Manual de Taller KAWASAKI KX250 (KX250R7F) MANUAL TALLER 2007

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KX250

Motorcycle

Service Manual

This quick reference guide will assist

you in locating a desired topic or pro-

cedure.

•Bend the pages back to match the

black tab of the desired chapter num-

ber with the black tab on the edge at

each table of contents page.

•Refer to the sectional table of contents

for the exact pages to locate the spe-

cific topic required.

Quick Reference Guide

General Information 1 j

Periodic Maintenance 2 j

Fuel System 3 j

Cooling System 4 j

Engine Top End 5 j

Engine Right Side 6 j

Engine Removal/Installation 7 j

Engine Bottom End/Transmission 8 j

Wheels/Tires 9 j

Final Drive 10 j

Brakes 11 j

Suspension 12 j

Steering 13 j

Frame 14 j

Electrical System 15 j

Appendix 16 j

KX250

Motorcycle

Service Manual

transmitted in any form or by any means, electronic mechanical photocopying, recording or otherwise,

without the prior written permission of Quality Divis ion/Consumer Products & Machinery Company/Kawasaki

Heavy Industries, Ltd., Japan.

No liability can be accepted for any inaccuracies or omissions in this publication, although every possible

care has been taken to make it as complete and accurate as possible.

The right is reserved to make changes at any time without prior notice and without incurring an obligation

to make such changes to products manufactured previously. See your Motorcycle dealer for the latest

information on product improvements incorporated after this publication.

All information contained in this publication is based on the latest product information available at the time

of publication. Illustrations and photographs in this publication are intended for reference use only and may

not depict actual model component parts.

LIST OF ABBREVIATIONS

A ampere(s) lb pound(s)

ABDC after bottom dead center m meter(s)

AC alternating current min minute(s)

ATDC after top dead center

newton(s)

BBDC before bottom dead center Pa pascal(s)

BDC bottom dead center PS horsepower

BTDC before top dead center psi pound(s) per square inch

°C degree(s) Celsius r revolution

DC direct current rpm revolution(s) per minute

farad(s)

TDC

top dead center

°F degree(s) Fahrenheit TIR total indicator reading

ft foot, feet Vvolt(s)

ggram(s) W watt(s)

h hour(s) Ω ohm(s)

L liter(s)

Read OWNER’S MANUAL before operating

Foreword

This manual is designed primarily for use by

trained mechanics in a properly equipped shop.

However, it contains enough detail and basic in-

formation to make it useful to the owner who de-

sires to perform his own basic maintenance and

repair work. A basic knowledge of mechanics,

the proper use of tools, and workshop proce-

dures must be understood in order to carry out

maintenance and repair satisfactorily. When-

ever the owner has insufficient experience or

doubts as to his ability to do the work, all ad-

justments, maintenance, and repair should be

carried out only by qualified mechanics.

In order to perform the work efficiently and

to avoid costly mistakes, read the text, thor-

oughly familiarize yourself with the procedures

before starting work, and then do the work care-

fully in a clean area. Whenever special tools or

equipment are specified, do not use makeshift

tools or equipment. Precision measurements

can only be made if the proper instruments are

used, and the use of substitute tools may ad-

versely affect safe operation.

To get the longest life out of your motorcycle:

•

Follow the Periodic Maintenance Chart in the

Service Manual.

•

Be alert for problems and non-scheduled

maintenance.

•

Use proper tools and genuine Kawasaki mo-

torcycle parts. Special tools, gauges, and

testers that are necessary when servicing

Kawasaki Motorcycles are introduced by the

Service Manual. Genuine parts provided as

spare parts are listed in the Parts Catalog.

•

Follow the procedures in this manual care-

fully. Don’t take shortcuts.

•

Remember to keep complete records of main-

tenance and repair with dates and any new

parts installed.

How to Use this Manual

In this manual, the product is divided into

its major systems and these systems make up

the manual’s chapters. The Quick Reference

Guide shows you all of the product’s system

and assists in locating their chapters. Each

chapter in turn has its own comprehensive Ta-

ble of Contents.

For example, if you want ignition coil informa-

tion, use the Quick Reference Guide to locate

the Electrical System chapter. Then, use the

Table of Contents on the first page of the chap-

ter to find the Ignition Coil section.

Whenever you see these WARNING and

CAUTION symbols, heed their i nstructions!

Always follow safe operating and maintenance

practices.

WARNING

This warning symbol identifies special

instructions or procedures which, if not

correctly followed, could result in per-

sonal injury, or loss of life.

CAUTION

This caution symbol identifies special

instructions or procedures which, if not

strictly observed, could result in dam-

age to or destruction of equipment.

This manual contains four more symbols (in

addition to WARNING and CAUTION) which will

help you distinguish different types of informa-

tion.

NOTE

○

This note symbol ind icates points of par-

ticular interest for more efficient and con-

venient operation.

•

Indicates a procedural step or work to be

done.

○

Indicates a procedural sub-step or how to do

the work of the procedural step it follows. It

also precedes the text of a NOTE.

Indicates a conditional step or what action to

take based on the results of the test or inspec-

tion in the procedural step or sub-step it fol-

lows.

In most chapters an exploded view illustration

of the system components follows the Table of

Contents. In these illustrations you will find the

instructions indicating which parts require spec-

ified tightening torque, oil, grease or a locking

agent during assembly.

GENERAL INFORMATION 1-1

General Information

Table of Contents

Before Servicing ..................................................................................................................... 1-2

Model Identification................................................................................................................. 1-7

General Specifications............................................................................................................ 1-8

Technical Information-Air Oil Separate System Inverted Front Fork ...................................... 1-11

Unit Conversion Table ............................................................................................................ 1-13

1-2 GENERAL INFORMATION

Before Servicing

Before starting to perform an inspection service or carry out a disassembly and reassembly opera-

tion on a motorcycle, read the precautions given below. To facilitate actual operations, notes, illustra-

tions, photographs, cautions, and detailed descriptions have been included in each chapter wherever

necessary. This section explains the items that require particular attention during the removal and

reinstallation or disassembly and reassembly of general parts.

Especially n ote the following:

Edges of Parts

Lift large or heavy parts wearing gloves to prevent injury

from possible sharp edges on the parts.

Solvent

Use a high flush-point solvent when cleaning parts. High

flush point solvent s hould be used according to directions

of the solvent manufacturer.

Cleaning vehicle before disassembly

Clean the vehicle thoroughly before disassembly. Dirt or

other foreign materials entering into sealed areas during ve-

hicle disassembly can cause excessive wear and decrease

performance of the vehicle.

Arrangement and Cleaning of Removed Parts

Disassembled parts are easy to confuse. Arrange the

parts according to the order the parts were disassembled

and clean the parts in order prior to assembly.

GENERAL INFORMATION 1-3

Before Servicing

Storage of Removed Parts

After all the parts including subassembly parts have been

cleaned, store the parts in a clean area. Put a clean cloth

or plastic sheet over the parts to protect from any foreign

materials that m ay collect before re-assembly.

Inspection

Reuse of worn or damaged parts may lead to serious ac-

cident. Visually inspect removed parts for corrosion, discol-

oration, or other damage. Refer to the appropriate sections

of this manual for service limits on individual parts. Replace

the parts if any damage has been found or if the part is be-

yond its service limit.

Replacement Parts

Replacement Parts must be KAWASAKI genuine or rec-

ommended by KAWASAKI. Gaskets, O rings, Oil seals,

Grease seals, circlips or cotter pins must be replaced with

new ones whenever disassembled.

Assembly Order

In most cases assembly order is the reverse of disassem-

bly, however, if assembly order is provided in this Service

Manual, follow the procedures given.

Tightening Sequ ence

Generally, when installing a part with several bolts, nut,

or screws, start them all in their holes and tighten them to

a snug fit. Then tighten them according to the specified se-

quence to prevent case warpage or deformation which can

lead to malfunction. Conversely when loosening the bolts,

nuts, or screws, first loosen all of them by about a quar-

ter turn and them remove them. If the specified tightening

sequence is not indicated, tighten the fasteners alternating

diagonally.

1-4 GENERAL INFORMATION

Before Servicing

Tightening Torque

Incorrect torque applied to a bolt, nut, or screw may

lead to serious damage. Tighten fasteners to the specified

torque using a good quality torque wrench.

Often, the tightening sequence is followed twice initial

tightening and final tightening with torque wrench.

Force

Use common sense during disassembly and assembly,

excessive force can cause expensive or hard to repair dam-

age. When necessary, remove screws that have a non

-permanent locking agent applied using an impact driver.

Use a plastic-faced mallet whenever tapping is necessary.

Gasket, O-ring

Hardening, shrinkage, or damage of both gaskets

and O-rings after disassembly can reduce sealing per-

formance. Remove old gaskets and clean the sealing

surfaces thoroughly so that no gasket material or other

material remains. Install new gaskets and replace used

O-rings when re-assembling

Liquid Gasket, Locking Agent

For applications that require Liquid Gasket or a

Non-permanent Locking Agent, clean the surfaces so

that no oil residue remains before applying liquid gasket or

non-permanent locking agent. Do not apply them exces-

sively. Excessive application c an clog oil passages and

cause serious damage.

Press

For items such as bearings or oil seals that must be

pressed into place, apply small amount of oil to the con-

tact area. Be sure to maintain proper alignment and use

smooth movements when installing.

GENERAL INFORMATION 1-5

Before Servicing

Ball Bearing and Needle Bearing

Do not remove pressed ball or needle unless removal is

absolutely necessary. Replace with new ones whenever

removed. Press bearings with the manufacturer and size

marks facing out. Press the bearing into place by putting

pressure on the correct bearing race as shown.

Pressing the incorrect race can cause pressure between

the inner and outer race and result in bearing damage.

Oil Seal, Grease Seal

Do not remove pressed oil or grease seals unless removal

is necessary. Replace with new ones whenever removed.

Press new oil seals with manufacture and size marks facing

out. Make sure the seal is aligned properly when installing.

Apply specified grease to the lip of seal before installing

the seal.

Circlips, Cotter Pins

Replace circlips or cotter pins that were removed with new

ones. Take care not to open the clip excessively when in-

stalling to prevent deformation.

Lubrication

It is important to lubricate rotating or sliding parts during

assembly to minimize wear during initial operation. Lubri-

cation points are called out throughout this manual, apply

the specific oil or grease as specified.

1-6 GENERAL INFORMATION

Before Servicing

Direction of Engine Rotation

When rotating the c rankshaft by hand, the free play

amount of rotating direction will affect the adjustment. Ro-

tate the crankshaft to positive direction (clockwise viewed

from output side).

Electrical Leads

A two-color lead is identified first by the primary color and

then the stripe color. Unless instructed otherwise, electrical

leads must be connected to those of the same color.

Instrument

Use a meter that has enough accuracy for an accurate

measurement. Read the manufacture’s instructions thor-

oughly before using the meter. Incorrect values may lead

to improper adjustments.

GENERAL INFORMATION 1-7

Model Identification

KX250-R1 Left Side View

KX250-R1 Right Side View

1-8 GENERAL INFORMATION

General Specifications

Items KX250-R1 KX250R6F ∼

Dimensions

Overall Length 2 185 mm (86.0 in.)

Overall Width 840 mm (33.1 in.) 815 mm (32.1 in.)

Overall Height 1 265 mm (49.8 in.)

Wheelbase

1 480 mm (58.3 in.)

Road Clearance 340 mm (13.4 in.)

Seat Height 965 mm (38.0 in.)

Dry Mass 97 kg (214 lb)

Curb Mass:

Front 49.9kg(110lb)

Rear

51.7kg(114lb)

Fuel Tank Capacity 8.2 L (2.2 US gal)

Engine

Type 2-stroke, single cylinder, piston reed valve

Cooling System Liquid-cooled

Bore and Stroke 66.4 × 72.0 mm (2.61 × 2.85 in.)

Displacement

249 cm³ (15.25 cu in.)

Compression Ratio:

Low Speed 10.5 : 1, (EUR) 10.2 : 1

High Speed 9.1 : 1, (EUR) 8.9 : 1

Carburetion System Carburetor, KEIHIN PWK38S

Starting System Primary kick

Ignition System CDI

Ignition Ti ming 14° BTDC @7 090 r/min (rpm)

Spark Plug NGK BR8ECMVX

Port Timing:

Inlet:

Open Full open

–

Scavenging:

Open 59.3° BBDC

Close 59.3° ABDC

Exhaust:

Open 82.0° BBDC (low speed), 93.1° BBDC (high speed)

Close 82.0° ABDC (low speed), 93.1° ABDC (high speed)

Lubrication System (Gasoline

:Oil)

Petrol mix (32 : 1)

Drive Train

Primary Reduction System:

Type Gear

Reduction Ratio 3.000 (63/21)

Clutch Type Wet, multi disc

GENERAL INFORMATION 1-9

General Specifications

Items KX250-R1 KX250R6F ∼

Transmission:

Type

5 speed, constant mesh, return shift

Gear Ratios:

1st 1.800 (27/15)

2nd 1.437 (23/16)

3rd 1.176 (20/17)

4th 1.000 (21/21)

5th

0.869 (20/23)

Final Drive System:

Type Chain drive

Reduction Ratio 3.923 (51/13)

Overall Drive Ratio 10.234 @Top gear

Transmission Oil:

Grade API S E, SF, or SG

API SH, SJ or SL with JASO MA

Viscosity SAE 10W-40

Capacity 0.85 L (0.90 US qt)

Frame

Type Tubular, semi-double cradle

Steering Angle 42° to either side

Caster (Rake Angle) 26°

Trail 105 mm (4.1 in.)

Front Tire:

Size 80/100-21 51M

Make/Type BRIDGESTONE M401, Tube type

(EUR) DUNLOP D755F, Tube type

Rear Tire:

Size 110/90-19 62M

Make/Type BRIDGESTONE M402, Tube type

(EUR) DUNLOP D755, Tube type

Rim Size:

Front 21 × 1.60

Rear 19 × 2.15

Front Suspension:

Type Telescopic fork (up side down)

Wheel Travel 300 mm (11.8 in.)

Rear Suspension:

Type

Swingarm (New U ni-trak)

Wheel Travel 310 mm (12.2 in.)

Brake Type:

Front and Rear

Single disc

Effective Disc Diameter:

Front 225 mm (8.9 in.)

Rear 215 mm (8.5 in.)

1-10 GENERAL INFORMATION

General Specifications

Specifications are subject to change without notice, and may not apply to every country.

EUR: Europe Model

US: United States Model

GENERAL INFORMATION 1-11

Technical Information-Air Oil Separate System Inverted Front Fork

This model has newly developed “air oil separate” inverted front fork.

utline

The design of the newly developed “air oil separate” inverted front fork aims at the improvement of

front suspension performance required for motocross racing. This new fork offers a higher level of

control and riding comfort achieved through consistent damping. Pressurization of the cylinder unit

prevents cavitation or the formation of air bubbles within the fork oil in low pressure zones within the

fork.

The cylinder unit and Travel Control Valve (TCV) provide a stepless, controlled feel of the front fork.

By controlling initial damping more efficiently, the fork is progressive and does not have potential hard

spots associated with inconsistent damping.

onstruction

The new fork, as shown, separates oil and air by using a cylinder unit similar to a shock absorber

within the fork. The cylinder unit r esides in the upper portion of the fork with the piston rod and fork

spring underneath. The TCV is located underneath the fork spring at the bottom of the inner fork

tube and provides damping resistance as the fork nears the lower part of it’s travel. Just like an

ordinary fork, the fork oil in the outer chamber, the airspring (air chamber), and fork spring also provide

compression damping.

Within the cylinder unit, a spring and free piston apply pressure to the oil and prevent oil/air cavitation

(the formation of bubbles within the fork oil caused by varying pressure). The floating piston also takes

up the additional volume within the cylinder unit as fluid is displaced by the piston rod. The free piston

is designed so that the varying pressure of the air chamber (airspring) outside the cylinder unit will not

affect the damping characteristics of the cylinder unit.

peration me chanism an d oil flow

The schematic drawing (A) illustrates the fork in a neutral position. The schematic drawing (B)

illustrates the direction of oil flow and the functioning of individual piston valves during fork operation.

The left arrows indicate oil flow during the rebound stroke and the right arrows during the compression

stroke.

(1) During compression: When the fork is compressed, the piston rod and rebound piston pass

through the oil within the cylinder unit. Oil is forced through the rebound piston and opens a

shimstack on the bottom of the rebound piston providing compression damping. Oil displaced by

the piston rod causes oil to flow through the c ompression piston opening the compression shims

creating further compression damping, and the free piston moves up to take up the displaced

volume of oil. The fork spring and air chamber also provide springing to assist in controlling fork

action.

As the fork nears the middle of its travel, the lower portion of the cartridge enters the TCV. The

TCV assists in controlling the rate at which the fork compresses, particularly in the middle of the

fork’s travel, by providing both speed and position sensitive damping. Once the fork nears the

end of its travel, the cylinder unit engages the large hydraulic bottoming stop at the bottom of the

fork to slow movement.

(2) During rebound: As the fork begins to rebound, the piston rod pulls the rebound piston through

the cylinder unit and oil is forced through the rebound piston, as shown by the left side arrows.

A shimstack on the top of the r ebound piston provides damping to control rebound speed. As

the piston rod comes out of the cylinder unit and the volume within the cylinder unit is reduced,

the free piston and spring maintain pressure on the oil and return oil to the chamber between the

pistons.

1-12 GENERAL INFORMATION

Technical Information-Air Oil Separate System Inverted Front Fork

Air O il Separate System Inverted Front Fork Diagram

1. Cylinder Unit

2. Outer Chamber

3. Oil Chamber

4. Oil Seal

5. Free Piston

6. Compression Piston

7. Rebound Piston

8. Fork Spring

9. Travel Control Valve

10. Inner Tube

11. Outer Tube

12. Air Chamber

13. Rebound Side

14. Compression Side

GENERAL INFORMATION 1-13

Unit Conversion Table

Prefixes for Units:

Prefix Symbol Power

mega M ×1000000

kilo k × 1 000

centi c ×0.01

milli m × 0.001

micro µ × 0.000001

Units o f Mass:

kg ×2.205=lb

g × 0.03527 = oz

Units of Volume:

L × 0.2642 = gal (US)

L × 0.2200 = gal (imp)

L × 1.057 = qt (US)

L × 0.8799 =

qt (imp)

L×2.113=

pint (US)

L × 1.816 = pint (imp)

mL × 0.03381 = oz (US)

mL × 0.02816 = oz (imp)

mL × 0.06102 = cu in

Units of Force:

N × 0.1020 = kgf

N × 0.2248 = lb

kgf × 9.807 = N

kgf × 2.205 = lb

Units of Length:

km × 0.6214 = mile

m × 3.281 = ft

mm × 0.03937 = in

Units of Torque:

N·m × 0.1020 = kgf·m

N·m × 0.7376 =

ft·lb

N·m × 8.851 = in·lb

kgf·m × 9.807 = N·m

kgf·m

×7.233=

ft·lb

kgf·m × 86.80 = in·lb

Units of Pressure:

kPa × 0.01020 = kgf/cm²

kPa × 0.1450 = psi

kPa × 0.7501 = cm Hg

kgf/cm²

× 98.07 = kPa

kgf/cm² × 14.22 = psi

cm Hg × 1.333 = kPa

Units o f Speed:

km/h × 0.6214 = mph

Units o f Power:

kW × 1.360 =

kW × 1.341 = HP

PS × 0.7355 = kW

× 0.9863 = HP

Units of Temperature:

PERIODIC MAINTENANCE 2-1

Periodic Maintenance

Table of Contents

Periodic Maintenance Chart .............. 2-3

Torque and Locking Agent................. 2-5

Specifications .................................... 2-9

Special Tools ..................................... 2-11

Periodic Maintenance Procedures..... 2-12

Fuel System.................................... 2-12

Fuel Hose and Connection

Check........................................ 2-12

Throttle Grip Free Play Inspection 2-12

Throttle Cable Adjustment ........... 2-12

Idle Speed Inspection .................. 2-13

Idle Speed Adjustment................. 2-13

Air Cleaner Element Cleaning and

Inspection.................................. 2-14

Fuel Tank and Tap Cleaning ........ 2-16

Fuel Tap Inspection...................... 2-16

Reed Valve Inspection ................. 2-16

Cooling System............................... 2-17

Coolant Level Inspection .............. 2-17

Coolant Deterioration Inspection .. 2-17

Coolant Draining .......................... 2-18

Coolant Filling .............................. 2-18

Air Bleeding.................................. 2-19

Cooling Hoses and Connections

Inspection.................................. 2-19

Engine Top End .............................. 2-20

Cylinder Head Warp Inspection ... 2-20

Cylinder Wear Inspection............. 2-20

Piston Diameter Measurement .... 2-20

Piston/Cylinder Clearance ........... 2-21

Piston Ring, Piston Ring Groove

Inspection.................................. 2-21

Piston Ring End Gap Inspection .. 2-22

Piston, Piston Pin, Connecting

Rod Wear Inspection................. 2-22

Exhaust Valve Clean and Inspect 2-22

Exhaust System ........................... 2-23

Muffler Baffle Change .................. 2-23

Engine Right Side ........................... 2-23

Clutch Lever Free Play Check ..... 2-24

Clutch Lever Free Play

Adjustment ................................ 2-24

Friction and Steel Plates Wear,

Damage Inspection ................... 2-25

Friction and Steel Plate Warp

Inspection.................................. 2-25

Engine Bottom End/Transmission .. 2-25

Transmission Oil Level Inspection 2-26

Transmission Oil Change............. 2-26

Wheel/Tires..................................... 2-27

Air Pressure Inspection/Adjust-

ment .......................................... 2-27

Tires Inspection............................ 2-27

Spoke Tightness Inspection......... 2-28

Rim Runout Inspection................. 2-28

Wheel/Bearing Inspection ............ 2-29

Final Drive....................................... 2-29

Drive Chain Slack Inspection ....... 2-29

Drive Chain Slack Adjustment ..... 2-30

Drive Chain Wear Inspection ....... 2-31

Drive Chain Lubrication................ 2-31

Sprocket Wear Inspection............ 2-32

Rear Sprocket Warp Inspection ... 2-32

Brakes............................................. 2-32

Brake Lever and Pedal Position

Adjustment ................................ 2-32

Brake Fluid Level Inspection........ 2-34

Brake Fluid Change ..................... 2-35

Brake Pad Wear Inspection ......... 2-37

Brake Master Cylinder Cup and

Dust Cover Replacement .......... 2-38

Caliper Fluid Seal and Dust Seal

Replacement............................. 2-39

Brake Hose and Connection

Check........................................ 2-42

Brake Hose Replacement ............ 2-42

Suspension..................................... 2-44

Front Fork Inspection ................... 2-44

Front Fork Oil Change (each fork

leg) ............................................ 2-44

Rear Shock Absorber Inspection . 2-52

Rear Shock Absorber Oil Change 2-52

Swingarm and Uni-Trak Linkage

Inspection.................................. 2-57

Swingarm and Uni-Track Linkage

Pivot Lubricate .......................... 2-57

Chain Guide Wear Inspection ...... 2-57

Chain Slipper Wear Inspection .... 2-57

Steering .......................................... 2-57

Steering Inspection ...................... 2-57

Steering Adjustment .................... 2-57

Stem Bearing Lubrication............. 2-60

2-2 PERIODIC MAINTENANCE

Frame ............................................. 2-60

Frame Inspection ......................... 2-60

Electrical System ............................ 2-60

Spark Plug Cleaning and

Inspection.................................. 2-60

General Lubrication ........................ 2-61

Lubrication ................................... 2-61

Nut, Bolt, and Fastener Tightness .. 2-63

Tightness Inspection .................... 2-63

PERIODIC MAINTENANCE 2-3

Periodic Maintenance Chart

The maintenance must be done in accordance with this chart to k eep the motorcycle in good running

condition.

FREQUENCY

OPERATION

Each

race

(or 2.5

hours)

Every 3

races

(or 7.5

hours)

Every 6

races

(or 15

hours)

Every 12

races

(or 30

hours)

See

Page

Spark plug - clean, gap †

•

R 2-60

Clutch - adjust

•

2-24

Clutch and friction plates - inspect †

•

2-25

Throttle cable - adjust

•

2-12

Air cleaner element - clean

•

2-14

Air cleaner element - replace If damaged 2-14

Carburetor - inspect and adjust

•

2-13

Transmission oil - change

•

2-26

Piston and piston ring - clean and inspect†

•

R 2-20

Cylinder head, cylinder - inspect

•

2-20

Small end bearing - inspect †

•

2-22

Reed valve - inspect †

•

2-16

Exhaust valve - clean and inspect

•

2-22

Muffler - clean and inspect†

•

2-23

Muffler packing - change

•

2-23

Kick pedal and shift pedal - clean

•

–

Engine sprocket - inspect †

•

2-32

Coolant - check †

•

2-17

Cooling hoses and connections - inspect †

•

2-19

Brake adjustment - inspect †

•

2-32

Brake pad wear - inspect †

•

2-37

Brake fluid level - inspect †

•

2-34

Brake fluid - change Every 2 years 2-35

Brake master cylinder cup and dust cover - replace Every 2 years 2-38

Brake c aliper fluid seal and dust seal - replace

Every 2 years 2-39

Brake hoses and pipe - replace Every 4 years 2-42

Brake hoses, connections - inspect †

•

2-42

Spoke tightness and rim runout - inspect †

•

2-28

Wheel bearing - inspect †

•

2-29

Drive chain - adjust

•

2-29

Drive chain - lubricate

•

2-31

Drive chain wear - inspect †

•

2-31

Chain slipper and guide - replace If damaged 2-57

Rear sprocket - inspect †

•

2-32

Front fork - inspect and clean

•

2-44

Front fork oil - change

•

2-44

2-4 PERIODIC MAINTENANCE

Periodic Maintenance Chart

FREQUENCY

OPERATION

Each

race

(or 2.5

hours)

Every 3

races

(or 7.5

hours)

Every 6

races

(or 15

hours)

Every 12

races

(or 30

hours)

See

Page

Rear shock oil - replace

•

2-52

Fuel system - clean

•

2-16

Fuel hose - replace Every 4 years 2-12

Fuel hose, connections - inspect †

•

2-12

Steering play - inspect †

•

2-57

Steering stem bearing - grease

•

2-60

Swing arm and Uni-Trak linkage pivots - grease

•

2-57

Swing arm and Uni-Trak linkage pivots - inspect †

•

2-57

Frame - clean and inspect

•

2-60

Wheel/tire (air pressure, excessive wear or

damage) - inspect

•

2-27

Rear shock absorber - i nspect

•

2-52

Nuts, bolts, fasteners - inspect †

•

2-63

General lubrication - perform

•

2-61

†: Replace, add, adjust, clean or torque if necessary.

R: Replace

PERIODIC MAINTENANCE 2-5

Torque and Locking Agent

Tighten all bolts and nuts to the proper torque using an accurate torque wrench. If insufficiently

tightened, a bolt or nut may become damaged, strip an internal thread, or break and then fall out. The

following table lists the tightening toque for the major bolts and nuts, and the parts requiring use of a

non-permanent locking agent or liquid gasket.

When checking the tightening toque of the bolts and nuts, first loosen the bolt or nut by half a turn

and then tighten to specified torque.

Letters used in the “Remarks” column mean:

AL: Tighten the two clamp bolts alternately two times to ensure eve tightening torque.

L: Apply a non-permanent locking agent to the threads.

LG: Apply liquid gasket to the threads.

S: Tighten the fasteners following the specified sequence.

Torque

Fastener

N·m kgf·m ft·lb

Remarks

Fuel System

Carburetor Top Cover Allen Bolts 3.9 0.40 35 in·lb

Reed Valve Screws 1.0 0.10 8.8 in·lb

Carburetor Holder Mounting Bolts 8.8 0.90 78 in·lb

Carburetor Holding Clamp Screw 1.5 0.15 13 in·lb

Air Cleaner Duct Clamp Screw 1.5 0.15 13 in·lb

Air Cleaner Duct Mounting N uts

3.0 0.30 27 in·lb

Air Cleaner Housing Bolts 8.8 0.90 78 in·lb

Rear Frame M ounting Bolts 34 3.5 25

Cooling System

Water P ump Cover Bolts 8.8 0.90 78 in·lb

Water Pump Cover Fitting Bolts 8.8 0.90 78 in·lb

Coolant Drain Plug 8.8 0.90 78 in·lb

Water Pump Impeller Bolt 6.9 0.70 61 in·lb

Right Engine Cover Bolts 8.8 0.90 78 in·lb

Radiator Shroud Bolts 8.8 0.90 78 in·lb

Radiator Mounting Bolts 8.8 0.90 78 in·lb

Radiator Screen Bolts 8.8 0.90 78 in·lb

Radiator Bracket Bolts 8.8 0.90 78 in·lb

Cooling Hose Clamp Screws 1.5 0.15 13 in·lb

Engine Top End

Main Exhaust Valve Cover Bolts

5.9 0.60 52 in·lb

Retaining Plate Bolts 5.9 0.60 52 in·lb

Subexhaust Valve Cover Bolts 8.8 0.90 78 in·lb

Cylinder Head Nuts

KX250-R1 25 2.5 18

KX250R6F ∼ 31 3.2 23

with

2.3 mm

Washer

Engine Mounting Bracket Nuts (Frame Side 8 mm) 29 3.0 22

Engine Mounting Bracket Nuts (Engine Side 10

mm)

49 5.0 22

KIPS Cover Bolts 5.9 0.60 52 in·lb

Governor Shaft Lever Mounting Bolt

5.9 0.60 52 in·lb

2-6 PERIODIC MAINTENANCE

Torque and Locking Agent

Torque

Fastener

N·m kgf·m ft·lb

Remarks

Sublever Allen Bolt

3.9 0.40 35 in·lb L

Main Lever Allen Bolt 3.9 0.40 35 in·lb L

Stopper Pin Allen Bolt 3.9 0.40 35 in·lb L

Cylinder Nuts

33 3.4 25

Muffler Damper Mounting Bolt 8.8 0.90 78 in·lb

Expansion Chamber Mounting Bolt 12 1.2 8.7

Muffler Mounting Bolts 8.8 0.90 78 in·lb

Inner Pipe Mounting Bolts 8.8 0.90 78 in·lb L

Muffler Pipe Mounting Bolts 8.8 0.90 78 in·lb L

Engine Right Side

Clutch Cover Bolts 8.8 0.90 78 in·lb

Right Engine Cover Bolts 8.8 0.90 78 in·lb

Governor Shaft Lever Positioning Plug

1.0 0.1 10 in·lb

Governor Shaft Lever Mounting Bolt 5.9 0.60 52 in·lb

Advancer

Lever Mounting Allen Bolts 3.9 0.4 35 in·lb L

Primary Gear Nut (KX250R6F ∼) 78 8.0 58

Clutch Hub Nut 98 10.0 72

Clutch Spring Bolts

8.8 0.90 78 in·lb

Gear Set Lever Nut 8.8 0.90 78 in·lb

Gear Set Lever Pivot Stud

– – –

L(Planted

Side)

Ratchet Plate Mounting Bolts 8.8 0.90 78 in·lb

Shift Mechanism Return Spring Pin 42 4.3 31 L

Shift Pedal Bolt

8.8 0.90 78 in·lb

Ratchet Guide Bolt 8.8 0.90 78 in·lb

Kick Pedal Mounting Bolt 25 2.5 18

Engine Removal/Installation

Engine Mounting Nuts 49 5.0 36

Engine Mounting Bracket Nuts:

Engine Side 10 mm 49 5.0 36

Frame Side 8 mm 29 3.0 22

Swing Arm Pivot Shaft Nut 98 10.0 72

Engine Bottom End/Transmission

Cylinder Stud

– – –

L(Planted

Side)

Crankcase Bolts

8.8

0.90 78 in·lb

Transmission Oil Drain Plug 20 2.0 14.5

Bearing Retaining Screws 4.9 0.50 43 in·lb L

Drive Shaft Bearing Retaining Bolts 8.8 0.90 78 in·lb

Shift Drum Bearing Retaining Bolts 8.8 0.90 78 in·lb

Shift Drum Operating Cam Bolt 24 2.4 17 L

Flywheel Nut 78 8.0 58

PERIODIC MAINTENANCE 2-7

Torque and Locking Agent

Torque

Fastener

N·m kgf·m ft·lb

Remarks

Wheels/Tires

Front Axle Nut 78 8.0 58

Front A xle Clamp Bolts 20 2.0 14.5 AL

Rear Axle Nut 110 11.0 80

Spoke Nipple Not less

than 2.2

Not less

than 0.22

Not less

than 19 in·lb

Final Drive

Rear Axle Nut 110 11.0 80

Engine Sprocket Cover Bolts 8.8 0.90 78 in·lb

Rear Sprocket Nuts 34 3.5 25

Brakes

Caliper Mounting Bolts (Front) 25 2.5 18

Brake Hose Banjo Bolts 25 2.5 18

Front Master Cylinder Clamp Bolts 8.8 0.90 78 in·lb S

Rear Master Cylinder Mounting Bolts 9.8 1.0 87 in·lb

Rear Master Cylinder Push Rod Locknut 18 1.8 13.0

Brake Disc Mounting Bolts:

Front 9.8 1.0 87 in·lb L

Rear 23 2.3 16.6 L

Caliper Bleed Va lves (Front, Rear) 7.8 0.8 69 in·lb

Caliper Holder Shaft 27 2.8 20

Brake Pad Bolt 18 1.8 13

Rear Brake P ad Bolt Plug 2.5 0.25 22 in·lb

Brake Pedal Mounting Bolt 25 2.5 18 L

Suspension

Front Fork Top Plug 29 3.0 22

Front Fork Clamp Bolts (Upper, Lower) 20 2.0 14.5 AL

Steering Stem Head Nut

78 8.0 58

Lock N ut/Adjuster Assembly 29 3.0 22

Adjuster Assembly 58 6.0 43 L

Base Valve Assembly 27 2.8 20

Front A xle Clamp Bolts 20 2.0 14.5 AL

Swingarm Pivot Shaft Nut 98 10.0 72

Ti e-rod Mounting Nut (Front, Rear)

83 8.5 61

Rocker Arm Pivot Nut 83 8.5 61

Rear Shock Absorber Mounting Nut (Upper) 39 4.0 29

Rear Shock Absorber Mounting Nut (Lower)

34 3.5 25

Steering

Steering Stem Head Nut 98 10.0 72

Steering Stem N ut 4.9 0.5 43 in·lb

Handlebar Holder Bolts 25 2.5 18

Front Fork Clamp Bolts (Upper, Lower) 20 2.0 14.5 AL

2-8 PERIODIC MAINTENANCE

Torque and Locking Agent

Torque

Fastener

N·m kgf·m ft·lb

Remarks

Frame

Rear Frame Mounting Bolt 34 3.5 25

Electrical System

Flywheel Nut 78 8.0 58

Stator Plate Mounting Screws 4.9 0.50 43 in·lb

Spark Plug 26 2.7 20

Magneto Cover Bolts 8.8 0.90 78 in·lb

Ignition Coil Mounting Bolts 8.8 0.90 78 in·lb

C.D.I Unit Mounting Bolts 8.8 0.90 78 in·lb

Basic Torque for General Fasteners

Torque

Threads diameter

(mm)

N·m

kgf·m ft·lb

5 3.4 ∼ 4.9 0.35 ∼ 0.50 30 ∼ 43 in·lb

6 5.9 ∼ 7.8 0.60 ∼ 0.80 52 ∼ 69 in·lb

8 14 ∼ 19 1.4 ∼ 1.9 10.0 ∼ 13.5

10 25 ∼ 34 2.6 ∼ 3.5 19.0 ∼ 25

12 44 ∼ 61 4.5 ∼ 6.2 33 ∼ 45

14 73 ∼ 98 7.4 ∼ 10.0 54 ∼ 72

16 115 ∼ 155 11.5 ∼ 16.0 83 ∼ 115

18 165 ∼ 225 17.0 ∼ 23.0 125 ∼ 165

20 225 ∼ 325 23 ∼ 33 165 ∼ 240

PERIODIC MAINTENANCE 2-9

Specifications

Item Standard Service Limit

Fuel System

Throttle G rip Free Play 2 ∼ 3mm(0.08∼ 0.12 in.)

–––

Air Cleaner Element Oil High quality foam air filter oil –––

Read Valve Warp 0.5 mm

(0.020 in.)

Cooling System –––

Coolant:

Type (Recommended) Permanent type antifreeze

Color Green

Mixed Ratio Soft water 50% and coolant 50%

Freezing Point –35°C (–31°F)

Total Amount 1.20 L (1.27 US qt)

Engine Top End

Cylinder Head Warp ––– 0.03 mm

(0.0012 in.)

Cylinder, Piston

Cylinder Inside Diameter (30 mm

(1.18 in.) below of the Cylinder

Head)

66.400 ∼ 66.415 mm (2.6142 ∼ 2.6148 in.)

66.46 mm

(2.617 in.)

Piston Diameter 66.336 ∼ 66.351 mm (2.6116 ∼ 2.6122 in.) 66.19 mm

(2.6059 in.)

Piston/Cylinder Clearance 0.049 ∼ 0.079 mm (0.0019 ∼ 0.0031 in.) –––

Piston Ring/Groove Clearance 0.025 ∼ 0.06 mm (0.00098 ∼ 0.00236 in.)

0.16 mm

(0.006 in.)

Piston Ring Groove Width 1.01 ∼ 1.03 mm (0.0398 ∼ 0.0406 in.)

1.11 mm

(0.044 in.)

Piston Ring Thickness 0.970 ∼ 0.985 mm (0.0382 ∼ 0.0388 in.) 0.90 mm

(0.035 in.)

Piston Ring End Gap 0.25 ∼ 0.45 mm (0.0098 ∼ 0.0177 in.)

0.75 mm

(0.030 in.)

Piston Pin Diameter 17.995 ∼ 18.000 mm

(0.7085 ∼ 0.7087 in.)

17.96 mm

(0.707 in.)

Piston Pin Hole Diameter 18.001 ∼ 18.011 mm

(0.7087 ∼ 0.7091 in.)

18.08 mm

(0.712 in.)

Small End Inside Diameter

22.003 ∼ 22.012 mm

(0.8663 ∼ 0.8666 in.)

22.05 mm

(0.868 in.)

Engine Right Side

Clutch Lever Free Play 8 ∼ 13 mm (0.3 ∼ 0.5 in.) –––

Friction Plate Thickness 2.92 ∼ 3.08 mm (0.115 ∼ 0.121 in.) 2.8 mm

(0.110 in.)

Steel Plate Thickness 1.46 ∼ 1.74 mm (0.057 ∼ 0.069 in.)

1.36 mm

(0.054 in.)

Friction Plate Warp

Not more than 0.15 mm (0.006 in.)

0.3 mm

(0.012 in.)

Steel Plate Warp Not more than 0.2 mm (0.008 in.) 0.3 mm

(0.012 in.)

2-10 PERIODIC MAINTENANCE

Specifications

Item Standard Service Limit

Engine Bottom End/Transmission

Transmission Oil:

Grade API SE, SF or SG

API SH, SJ or SL with JASO MA

Viscosity

SAE 10W-40

Capacity 0.85 L (0.90 US qt) –––

Wheels/Tires

Rim Runout:

Axial TIR 1.0 mm (0.04 in.) or less

TIR 2 mm (0.08

in.)

Radial TIR 1.0 mm (0.04 in.) or less

TIR 2 mm (0.08

in.)

Final Drive

Drive Chain Slack 52 ∼ 62 mm (2.05 ∼ 2.44 in.) –––

Drive Chain 20 Link Length 317.5 ∼ 318.2 mm (12.50 ∼ 12.53 in.) 323 mm

(12.72 in.)

Engine Sprocket Diameter 55.48 ∼ 55.68 mm (2.184 ∼ 2.192 in.)/13T

54.8 mm

(2.157 in.)

Rear Sprocket Diameter

247.64 ∼ 248.14 mm

(9.750 ∼ 9.769 in.)/51T

247.3 mm

(9.736 in.)

Rear Sprocket Runout TIR 0.4 mm (0.016 in.) or less TIR 0.5 mm

(0.020 in.)

Brakes

Brake Lever Free Play Adjustable (to suit rider) –––

Brake Fluid:

Grade:

Front DOT3 or DOT4 –––

Rear DOT4 –––

Brake Pad Lining Thickness:

Front 3.8 mm (0.150 in.) 1 mm (0.04 in.)

Rear 6.4 mm (0.252 in.) 1 m m (0.04 in.)

Suspension

Fork Oil:

Oil Viscosity KHL15-10 (KAYABA 01) or equivalent

Oil Quantity: (Adjustable range)

Outer (Outer/Inner Tubes):

KX250-R1 300 mL (10.14 US oz.) 280 ∼ 320 mL

(9.47 ∼ 10.82

US oz.)

KX250R6F ∼ 310 mL (10.48 US oz.) 290 ∼ 330 mL

(9.80 ∼ 11.16

US oz.)

Inner (Subtank) 160 mL (5.41 US oz.) –––

Electrical System

Spark Plug Gap 0.7 ∼ 0.8 mm (0.028 ∼ 0.031 in.) –––

PERIODIC MAINTENANCE 2-11

Special Tools

Spark Plug Wrench, Hex 21:

57001-110

Steering Stem Nut Wrench:

57001-1100

Jack:

57001-1238

TopPlugWrench(46mm):

57001-1622

2-12 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Fuel System

Fuel Hose and Connection Check

○

Check the fuel hose periodically in accordance with the

Periodic Maintenance Chart, and if the motorcycle is not

properly handled, the inside the fuel line can cause fuel

to leak [A] or the hose to burst. Remove the fuel tank and

check the fuel hose.

Replace the fuel hose if any fraying, cracks [B] or bulges

[C] are noticed.

•

Check that the hoses are securely c onnected and clamps

are tightened correctly.

•

When installing, route the hoses according to Cable,

Wire, and Hose Routing section in the Appendix chapter.

•

When installing the fuel hoses, avoid sharp bending, kink-

ing, flattening or twisting, and route the fuel hoses with a

minimum of bending so that the fuel flow will not be ob-

structed.

Replace the hose if i t has been sharply bent or kinked.

ThrottleGripFreePlayInspection

•

Check throttle grip free play [B] by lightly turning the throt-

tlegrip[A]backandforth.

If the free play is improper, adjust the throttle cable.

Throttle Grip Free Play

Standard: 2 ∼ 3 mm (0.08 ∼ 0.12 in.)

•

Check that the throttle grip moves smoothly from full open

to close, and the throttle closes quickly and completely in

all steering positions by the return spring.

If the throttle grip does not return properly, check the throt-

tle cable routing, grip free play, and cable damage. Then

lubricate the throttle cable.

•

Run the engine at the idle speed, and turn the handlebar

all the way to the right and left to ensure that the idle speed

does not change.

If the idle speed increase, check the throttle cable free

play and the cable routing.

Throttle Cable Adjustment

•

Loosen the locknut [A] at the upper end of the throttle

cable.

•

Turn the adjuster [B] until the proper amount of throttle

grip free play is obtained.

•

Tighten the locknut.

PERIODIC MAINTENANCE 2-13

Periodic Maintenance Procedures

If the throttle grip free play cannot be adjusted with the

adjuster at the upper end of the throttle cable, use the

cable adjuster [A] at the carburetor.

•

Pull the boot off of the carburetor top. Make the necessary

free play adjustment at the lower cable adjuster, tighten

the locknut [B], and install the boot.

•

Turn the handlebar from side to side while idling the en-

gine. If idle speed varies, the throttle cable m ay be poorly

routed or it may be damaged.

WARNING

Operation with an improperly adjusted, incorrectly

routed, or damaged cable could result in an unsafe

riding condition.

Idle Speed Inspection

•

Start the engine and warm it up thoroughly.

•

With the engine idling, turn the handlebar to both sides.

If handlebar movement changes the idle speed, the throt-

tle cable may be improperly adjusted or incorrectly routed,

or it may be damaged. Be sure to correct any of these

conditions before riding (see Cable, Harness, Hose Rout-

ing in the Appendix chapter).

WARNING

Operation with an improperly adjusted, incorrectly

routed, or damaged cable could result in an unsafe

riding condition.

•

Check idle speed.

Adjust it as needed.

Idle Speed Adjustment

•

First turn in the air screw [A] until it seats lightly, and back

it out the specified number of turns. (see specifications in

the Fuel System chapter)

•

Start the engine and warm it up thoroughly.

•

Turn the idle adjusting screw [B] to obtain desired idle

speed. If no idle is preferred, turn out the screw until the

engine stops.

•

Open and close the throttle a few times to make sure that

the idle speed is as desired. Readjust if necessary.

2-14 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Air Cleaner Element Cleaning and Inspection

The air cleaner element should be cleaned and oiled

before each race or practice session. A dirty or improperly

oiled element can diminish engine performance, cause

spark plug fouling, and could affect long term durability of

the engine. After cleaning, oil the air cleaner element using

a high-quality foam-air filter oil.

NOTE

○

In dusty areas, the element should be c leaned more

frequently than recommended interval.

○

After riding through rain or on muddy roads, the element

should be cleaned immediately.

○

Since r epeated cleaning opens the pores of the ele-

ment, replace it with a new one in accordance with the

Periodic Maintenance Chart. Also, if there is a break in

the element material or any other damage to the ele-

ment, replace the element with a new one.

WARNING

Clean the element in a well-ventilated area, and take

care that there are no sparks or flame anywhere

near the working area; this includes any appliance

with a pilot light. Because of the danger of highly

flammable liquids, do not use gasoline or a low

flash-point solvent to clean the element.

•

Remove:

Seat (see Frame chapter)

Wing Bolt [A]

Air Cleaner Element [B]

•

Stuff a clean, lint-free towel into the carburetor so no dirt

is allowed to enter the carburetor.

•

Wipe out the inside of the air cleaner housing with a clean

damp towel.

CAUTION

Check inside of the inlet tract and carburetor for

dirt. If dirt is present, clean the intake tract and car-

buretor thoroughly. You may also need to replace

the element and seal the housing and inlet tract.

•

Separate the element [A] from the frame [B].

PERIODIC MAINTENANCE 2-15

Periodic Maintenance Procedures

•

Clean the element [A] in a bath of a high-flash-point s ol-

vent using a soft bristle brush.

•

Squeeze it dry in a clean towel [A]. Do not wring the ele-

ment or blow it dry; the element can be damaged.

•

Check all the parts of the element for visible damage.

If any of the parts of the element are damaged, replace

them.

•

After cleaning, saturate the element with a high-quality

foam-air-filter oil, squeeze out the excess, then wrap it in

a clean towel and squeeze it as dry as possible.

○

Be careful not to tear the sponge filter.

•

Assemble the element.

•

Remove the towel from the carburetor.

•

Apply grease to all connections and screw holes in the air

cleaner housing and intake tract.

•

Install the element onto its frame, and coat the element

lip and lip seat with a thick layer of all-purpose grease to

assure a complete seal.

•

Install the air cleaner element so that its tab faces [A]

upward and its projections [B] align with the holes [C] in

the housing.

•

Tighten the wing bolt [D]

•

Install the seat.

2-16 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Fuel Tank and Tap Cleaning

WARNING

Clean the fuel tank in a w ell-ventilated area, and

take care that there is no sparks or flame anywhere

near the working area. Because of the danger of

highly flammable liquids, do not use gasoline or low

flash-point solvent to clean the tank.

•

Remove the fuel tank and drain it.

•

Pour some high-flash-point solvent into the fuel tank and

shake the tank to remove dirt and fuel deposits.

•

Pour the solvent out of the tank.

•

Remove the fuel tap from the tank by taking out the bolts.

•

Clean the fuel tap filter screen in a high flash-point sol-

vent.

•

Pour high-flash-point solvent through the tap in all lever

positions.

•

Dry the tank and tap with compressed air.

•

Install the tap in the fuel tank.

•

Install the fuel tank.

Fuel Tap Inspection

•

Remove the fuel tap.

•

Check the fuel tap filter screen [A] for any breaks or dete-

rioration.

If the fuel tap screen have any breaks or is deteriorated, it

may allow dirt to reach the carburetor, causing poor run-

ning. Replace the fuel tap.

If the fuel tap leaks, or allows fuel to flow when it is at OFF

position, replace the damaged O-ring [B].

Reed Valve Inspection

•

Inspect the reeds for cracks, folds, or other visible dam-

age.

If there is any doubt as to the condition of a reed, replace

the reed valve part with a new one.

If a reed becomes wavy, replace the valve part with a new

one even if its warp is less than the service limit.

•

Measure the clearance between the reed [A] and holder

[B], and check the reed warp as shown.

If any one of the clearance measurements exceeds the

service limit, replace the damaged valve parts with a new

one.

Reed Warp

Service Limit: 0.5 mm (0.020 in.)

PERIODIC MAINTENANCE 2-17

Periodic Maintenance Procedures

Cooling System

Check the coolant level each day before riding the motor-

cycle, and replenish coolant if the level is low. Change the

coolant in accordance with the Periodic Maintenance C hart.

WARNING

To avoid burns, do not remove the radiator cap

or try to inspect the coolant level or change the

coolant when the engine is still hot. Wait until it

cools down.

Coolant Level Inspection

NOTE

○

Check the level when the engine is cold (room or ambi-

ent temperature).

•

Place the motorcycle by using the side stand so that the

radiator cap is located uppermost in order to exhaust the

air accumulated in the radiator.

•

Remove the radiator cap [A].

NOTE

○

Remove the radiator cap in two steps. First turn the

cap counterclockwise to the first stop and wait there for

a few seconds. Then push down and turn it further in

the same direction and remove the cap.

•

Check the coolant level. The coolant level [A] should be

at the bottom of the filler neck [B].

If the coolant l evel is low, add coolant through the filler

opening to the bottom of the filler neck. Install the cap.

Recommended coolant:

Permanent type of antifreeze (soft water and ethylene

glycol plus corrosion and rust inhibitor chemicals for

aluminum engines and radiators)

Water and coolant mixture ratio:

1 : 1 (water 50%, Coolant 50%)

Total amount:

1.20 L (1.27 US qt.)

Coolant Deterioration Inspection

•

Visually inspect the coolant.

If whitish cotton-like wafts are observed, aluminum parts

in the cooling system are corroded. If the coolant is

brown, iron or steel parts are rusting. In either case, flush

thecoolingsystem.

If the coolant gives off an abnormal smell, check for a

cooling system leak. It may be caused by exhaust gas

leaking into the cooling system.

2-18 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Coolant Draining

The coolant should be changed periodically to ensure

long engine life.

WARNING

To avoid burns, do not remove the radiator cap or

try to change the coolant when the engine is still

hot. Wait until it cools down.

Coolant on tires will make them slippery and can

cause an accident and injury. Immediately wipe up

or wash away any coolant that spills on the frame,

engine or other painted parts. Since coolant is

harmful to the human body, do not use for drinking.

•

Remove the radiator cap.

NOTE

○

Remove the radiator cap in two steps. First turn the

cap counterclockwise to the first stop and wait there for

a few seconds. Then push down and turn it further in

the same direction and remove the cap.

•

Place a container under the coolant drain plug [A], and

drain the coolant from the radiator and engine by remov-

ing the drain plug on the water pump cover. Immediately

wipe or wash out any coolant that spills on the frame, en-

gine, or wheel.

•

Inspect the old coolant for visual evidence of corrosion

and abnormal smell (see Coolant Deterioration Inspec-

tion).

Coolant Filling

CAUTION

Use coolant containing corrosion inhibitors made

specifically for aluminum engines and radiators in

accordance with the instruction of the manufac-

ture’s. Soft or distilled water must be used with the

antifreeze (see below for antifreeze) in the cooling

system. If hard water is used in the system, it

causes scale accumulation in the water passages,

and considerably reduces the efficiency of the

cooling system.

Recommended Coolant

Type:

Permanen t type anti fre ez e (soft water

and ethylene glycol plus corrosion

and rust inhibitor chemicals for

aluminum engines and radiators)

Color: Green

Mixed ratio:

Soft water 50%, Coolant 50%

Freezing point:

−35°C (−31°F)

Total amount:

1.20 L (1.27 US qt.)

PERIODIC MAINTENANCE 2-19

Periodic Maintenance Procedures

•

Install the drain plug.

○

Replace the gasket with a new one.

Torque - Coolant Drain Plug on Water Pump Cover: 8.8 N·m

(0.90 kgf·m, 78 in·lb)

•

Fill the radiator up to the bottom of the radiator filler neck

[B] with coolant [A], and install the cap, turning it clockwise

about 1/4 turn.

NOTE

○

Pour in the coolant slowly so that it can expel the air

from the engine and radiator. The radiator cap must be

installed in two steps. First turn the cap clockwise to the

first stop. Then push down on it and turn it the rest of

the way.

•

Check the cooling system for leaks.

Air Bleeding

Before putting the motorcycle into operation, any air

trapped in the cooling system must be removed as follows.

•

Start the engine, warm up the engine thoroughly, and then

stop the engine. Wait until the engine cools down.

•

Remove the radiator cap.

•

Check the coolant level.

If the coolant level is low, add coolant up to the bottom of

the filler neck.

•

Install the radiator cap.

•

Check the cooling system for leaks.

Cooling Hoses and Connections Inspection

○

The high pressure inside the cooling hose [A] can cause

coolant to leak [B] or the hose to burst if the line is not

properly maintained. Visually inspect the hoses for signs

of deterioration. Squeeze the hoses. A hose should not

be hard and brittle, nor should it be soft or swollen.

Replace the hose if any fraying, cracks [C] or bulges [D]

are noticed.

•

Check that the hoses are securely connected and clamps

are tightened correctly.

2-20 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Engine Top End

Cylinder Head Warp Inspection

•

Lay a straightedge [A] across the lower surface of the

head at several different points, and measure warp by

inserting a thickness gauge [B] between the straightedge

and the head.

If warp exceeds the service limit, repair the mating sur-

face. Replace the cylinder head if the mating surface is

badly damaged.

Cylinder Head Warp

Service Lim it: 0.03 mm (0.0012 in.)

Cylinder Wear Inspection

NOTE

○

Measure the cylinder inside diameter when the cylinder

is cold (room or ambient temperature).

•

Visually Inspect the inside of the cylinder for scratches

and abnormal wear.

If the cylinder is damaged or badly worn, replace i t with a

new one.

•

Since there is a difference in cylinder wear in different di-

rections, take a side-to-side and a front-to back measure-

ment shown in the figure.

If any of the cylinder inside diameter measurements ex-

ceeds the service limit, the cylinder must be replaced with

a new one since the PLATING cylinder cannot be bored

or honed.

(A): 30 mm (1.2 in.)

Cylinder Inside D iameter

Standard: 66.400 ∼ 66.415 mm (2.6142 ∼ 2.6148

in.), and less than 0.01 mm (0.0004

in.) difference between any two

measurements.

Service Limit: 66.46 mm (2.617 in.), or more than 0.05

mm (0.020 in.) difference between any

two measurements.

Piston Diameter Measurement

•

Measure the outside diameter of the piston 20.5 mm (0.81

in.) [A] up from the bottom of the piston at a right angle to

the direction of the piston pin.

If the measurement is under the service limit, replace the

piston.

(A): 20.5 mm (0.81 in.)

Piston Diameter

Standard: 66.336 ∼ 66.351 m m (2.6116 ∼ 2.6122 in .)

Service Lim it: 66 .19 mm (2.606 in.)

PERIODIC MAINTENANCE 2-21

Periodic Maintenance Procedures

Piston/Cylinder Clearance

The piston-to-cylinder clearance is measured whenever a

piston or cylinder is replaced with a new one. The standard

piston-to-cylinder clearance must be adhered to whenever

the cylinder is replaced.

If only a piston is replaced, the clearance may exceed the

standard slightly. But it must not be less than the minimum,

in order to avoid piston seizure.

The most accurate way to find the piston clearance is

by making separate piston and cylinder diameter measure-

ments and then computing the difference between the two

values. Measure the piston diameter as just described, and

measure the cylinder diameter at the very bottom of the

cylinder.

Piston/Cylinder Clearance

Standard: 0.049 ∼ 0.079 mm (0.0023 ∼ 0.0031 in.)

Piston Ring, Piston Ring Gro ove Inspection

•

Visually inspect the piston rings and the piston ring

grooves.

If the rings are worn unevenly or damaged, they must be

replaced.

If the piston ring grooves are w orn unevenly or damaged,

the piston must be replaced and fitted with new rings.

•

Check for uneven groove wear by inspecting the ring seat-

ing.

•

The rings should fit perfectly parallel to the groove sur-

faces. If not, the piston must be replaced.

•

With the piston ring in its groove, make several mea-

surements with a thickness gauge [A] to determine piston

ring/groove clearance.

If the clearance exceeds the service limit, measure the

thickness of the piston ring

If the ring has worn down to less than the service limit,

replace the ring; if the groove width exceeds the service

limit, replace the piston.

Piston Ring/Groove Clearance

Standard: 0.025 ∼ 0.060 mm (0.0010 ∼ 0.0024 in.)

Service Limit: 0.16 mm (0.006 in.)

Piston Rin g Thickness

Standard: 0.970 ∼ 0.985 mm (0.0382 ∼ 0.0388 in.)

Service Limit: 0.90 mm (0.035 in.)

Piston Ring Groove Width

Standard: 1.01 ∼ 1.03 mm (0.0398 ∼ 0.0406 in.)

Service Limit: 1.11 mm (0.04 4 in.)

2-22 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Piston Ring End Gap Inspection

•

Place the piston ring [A] inside the cylinder [B], using the

piston to locate the ring squarely in place.

•

Set it close to the bottom of the cylinder, where cylinder

wear is low.

•

Measure the gap between the ends of the ring with a thick-

ness gauge [C]

If the gap is wider than the service limit, the ring is over-

worn and must be replaced.

Piston Ring End Gap

Standard: 0.25 ∼ 0.45 mm (0.0098 ∼ 0.0177 in.)

Service Lim it: 0.75 mm (0.030 in.)

Piston, Piston Pin, Connecting Rod Wear Insp ection

•

Visually inspect the snap ring [A] still fitted in place.

If the ring shows weakness or deformation, replace the

ring. Also if the pin hole groove shows excessive wear,

replace the piston.

•

Measure the diameter of the piston pin [B] with a microm-

eter.

If the piston pin diameter is less than the s ervice limit at

any point, replace the piston pin.

•

Using a cylinder gauge, measure the diameter of both of

piston pin holes [C] in the piston and the inside diameter

of the c onnecting rod small end.

If either piston pin h ole diameter exceeds the service limit,

replace the piston.

If the connecting rod small end inside diameter exceeds

the service limit, replace the crankshaft assembly.

•

Check the needle bearing [D].

○

The rollers in a needle bearing normally w ear very little,

and wear is difficult to m easure. Instead of measuring, in-

spect the bearing for abrasion, color change, other dam-

age.

If there is any doubt as to the condition of a needle bear-

ing, replace the bearing and piston pin.

Piston Pin Diameter

Standard: 17.99 5 ∼18.000 mm (0.7085 ∼ 0.7087 in.)

Service Limit: 17.96 mm (0.707 in.)

Piston Pin Hole Diameter

Standard: 18.00 1 ∼ 18.011 mm (0.7087 ∼ 0.7091 in.)

Service Limit: 18.08 mm (0.712 in.)

Small End Inside Diameter

Standard: 22.00 3 ∼ 22.012 mm (0.8663 ∼ 0.8666 in.)

Service Limit: 22.05 mm (0.868 in.)

Exhaust Valve Clean and Inspect

•

Refer to Exhaust Valve (KIPS) section in the Engine Top

End chapter.

PERIODIC MAINTENANCE 2-23

Periodic Maintenance Procedures

Exhaust System

•

The exhaust system, in particular, the baffle is equipped

in the muffler body to reduce exhaust noise and conduct

the exhaust gases away from the rider while minimizing

power loss. If carbon has built up inside the baffle, ex-

haust efficiency is reduced, causing engine performance

to drop.

•

If the muffler body is badly damaged, dented, cracked or

rusted, replace it. Replace the muffler baffle if the exhaust

noise becomes too loud or engine performance drops.

Muffler Baffle Change

•

Remove the muffler body.

•

Remove the inner pipe mounting bolts [A], and pull the

muffler pipe [B] from the muffler body.

•

Unscrew the i nner pipe mounting bolts [A].

•

Pull the inner pipe [B] from the muffler body.

•

Pull off the old muffler baffle, and install the new muffler

baffle [A] into the muffler body.

•

Apply silicone sealant to the circumference [B] of the muf-

fler pipe and inner pipe.

•

Apply a non-permanent locking agent to the pipe mount-

ing bolts.

•

Tighten:

Torque - Inner Pipe Mounting Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

Muffler Pipe Mounting Bolts: 8.8 N·m (0.90 kgf·m,

78 in·lb)

•

Install the muffler body.

Torque - Muffler Mounting Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

Engine Right S ide

WARNING

To avoid a serious burn, never touch the hot engine

or exhaust chamber during clutch adjustment.

2-24 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Clutch Lever Free Play Check

•

Slide the clutch lever dust covers [A] out of place.

•

Check that the clutch cable upper end is fully seated in

the adjusting bolt [B].

•

Check that the clutch lever [C] has 8 ∼ 13 mm (0.3 ∼ 0.5

in.) of play [D].

If it does not, adjust the lever play.

Clutch Lever Free Play Adjustment

•

Slide the clutch lever dust cover out of place.

•

Turn the adjuster [A] so that the clutch lever will have 8 ∼

13 mm (0.3 ∼ 0.5 in.) of play.

NOTE

○

Be sure that the outer cable end at the clutch lever is

fully seated in the adjusting bolt at the clutch lever, or

it could slip into the place later, creating enough cable

play to prevent clutch disengagement.

•

If it cannot be done, loosen the locknut [A] at the middle

of the c lutch cable, and turn the adjusting nut [B] so that

clutch lever has 8 ∼ 13 mm (0.3 ∼ 0.5 in.) of play.

•

After the adjustment is made, tighten the l ocknut, and

start the engine and check that the clutch does not slip

and that it release properly.

PERIODIC MAINTENANCE 2-25

Periodic Maintenance Procedures

Friction and Steel Plates Wear, Damage Inspection

•

Visually inspect the friction and steel plates to see if they

show any signs of seizure, or uneven wear.

If any plates show signs of damage, replace the friction

plates and steel plates as a set.

•

Measure the thickness [A] of the friction plates [B] and

steel plates with vernier calipers.

If they have worn past the service limit, replace them with

new ones.

Friction Plate Thickness

Standard: 2.92 ∼ 3.08 mm (0.115 ∼ 0.121 in.)

Service Limit: 2.8 m m (0.110 in.)

Steel Plate Thickness

Standard: 1.46 ∼ 1.74 mm (0.057 ∼ 0.069 in.)

Service Limit: 1.36 mm (0.054 in.)

Friction and Steel Plate Warp Inspection

•

Place each friction plate or steel plate on a surface plate,

and measure the gap between the surface plate [A] and

each friction plate or steel plate [B] with a thickness gauge

[C]. The gap is the amount of friction or steel plate warp.

If any plate i s warped over the service limit, replace it with

a new one.

Friction and Steel Plates Warp

Standard:

Friction Plate

0.15 mm (0.006 in.) or less

Steel Plate 0.2 mm (0.008 in.) or less

Service Limit:

Friction Plate

0.3 mm (0.012 in.)

Steel Plate 0.3 mm (0.012 in.)

Engine Bottom End/Transmission

In order for the transmission and clutch to function prop-

erly, always maintain the transmission oil at the proper level

and change the oil periodically.

WARNING

Motorcycle operation with insufficient, deteri-

orated, or contaminated transmission oil will

accelerated wear and may result in transmission

seizure, and injury.

2-26 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Transmission Oil Level Inspection

•

Situate the motorcycle so that it is perpendicular to the

ground.

•

If the motorcycle has just been used, wait several minutes

until the oil settles.

•

Check that the oil level comes up between the upper level

[A] and lower level [B] through the oil level gauge [C] on

the clutch cover.

If the oil level is too high, remove the excess oil through

the oil filler opening using a syringe or some other suitable

device.

If the o il level is too low, add the correct amount of oil.

Use the same type and make of oil that is already in the

engine.

NOTE

○

If the transmission oil type and make are unknown, use

any brand of the specified oil to top up the level in pref-

erence to running the engine with the oil level low. Then

at your earliest convenience, change the oil completely.

Transmission Oil Change

•

Warm up the engine thoroughly so that the oil will pick up

any sediment and drain easily. Then stop the engine.

•

Place an oil pan beneath the engine.

•

Removethetransmissionoildrainplug[A]onthebottom

of the engine, and let the oil drain completely.

NOTE

○

Hold the motorcycle upright so that the oil may drain

completely.

•

Replace the gasket at the drain plug with a new one.

•

After the oil has completely drained out, install the drain

plug with the gasket, and tighten it.

Torque - Transmission Oil Drain Plug: 20 N·m (2.0 kgf·m,

14.5 ft·lb)

•

Fill the engine with a good quality engine oil specified be-

low.

•

Check the oil level.

Recommended Transmission Oil

Grade API SE, SF or SG

API SH, SJ or SL with JASO MA

Viscosity

SAE10W-40

Capacity 0.85 L (0.90 US qt.)

NOTE

○

Although 10W-40 engine oil is the recommended oil

for most conditions, the oil viscosity may need to be

changed to accommodate atmospheric conditions in

your riding area.

PERIODIC MAINTENANCE 2-27

Periodic Maintenance Procedures

Wheel/Ti res

Air Pressure Inspection/Adjustment

•

Using tire air pressure gauge [A], measure the tire pres-

sure when the tires are cold.

Adjust the tire air pressure to suit track conditions and

rider preference, but do not stray too far from the recom-

mended pressure.

Track Condition

Tire Pressure

When the track is wet, muddy, sandy

or slippery, reduce the tire pressure

to increase the tire tread surface on

the ground.

80kPa(0.8kgf/cm²,

11 psi)

↑

When the track is pebbly or hard,

increasethetirepressuretoprevent

damage o r punctures, through the

tires w ill skid more easily.

↓

100 kPa (1.0 kgf/cm ²,

14 psi)

Tires Inspection

As the tire tread wears down, the tire becomes more sus-

ceptible the puncture and failure.

•

Remove any imbedded stones or other foreign particles

from the tread.

•

Visually inspect the tire for cracks and cuts, replacing the

tire in case of bad damage. Swelling or high spots indi-

cate internal damage, requiring tire replacement.

WARNING

To ensure safe handling and stability, use only the

recommended standard tires for replacement, in-

flated to the standard pressure.

NOTE

○

Check and balance the wheel when a tire is replaced

with a new one.

Standard Tire

Front:

Size 80/100-21 51M

Make

BRIDESTONE (EUR) DUNLOP

Type

M401, Tube (EUR) D755F, Tube

Rear:

Size 110/90-19 62M

Make

BRIDESTONE M402 (EUR) DUNLOP

Type

M402, Tube (EUR) D755, Tube

2-28 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Spoke Tightness Inspection

•

Check that all the spokes are tightened evenly.

If spoke tightness is uneven or loose, tighten the s poke

nipples evenly.

Torque - Spoke Nipples: 2.2 N·m (0.22 kgf·m, 19 in·lb)

•

Check the rim runout.

WARNING

If any spoke breaks, it should be r eplaced immedi-

ately. A missing spoke places an additional load on

the other spokes, which will eventually cause other

spokes to break.

Rim Runout Inspection

•

Place the jack under the frame so that the front/rear wheel

off the ground.

Special Tool - Jack: 57001-1238

•

Inspect the rim for small cracks, dents, bending, or warp-

ing.

If there is any damage to the rim, it must be replaced.

•

Set a dial gauge against the side of the rim, and rotate

the rim to measure the axial runout [A]. The difference be-

tween the highest and lowest dial readings is the amount

of runout.

•

Set a dial gauge against the outer circumference of the

rim, and rotate the rim to measure radial runout [B]. The

difference between the highest and lowest dial readings

is the amount of runout.

If rim runout exceeds the service limit, check the wheel

bearings first. Replace them if they are damaged. If the

problem is not due to the bearings, correct the rim warp

(runout). A certain amount of rim warp can be corrected

by recentering the rim. Loosen some spokes and tighten

others within the standard torque to change the position of

different parts of the rim. If the rim is badly bent, however,

it must be replaced.

Rim Runout (with tire installed)

Standard:

Axial

TIR 1.0 mm (0.039 in.) or less

Radial

TIR 1.0 mm (0.039 in.) or less

Service Li mit:

Axial

TIR 2 mm (0.08 in.)

Radial

TIR 2 mm (0.08 in.)

PERIODIC MAINTENANCE 2-29

Periodic Maintenance Procedures

Wheel/Bearing Inspection

•

Using a jack, raise the front wheel off the ground (see

Wheels/Tires chapter).

Special Tool - Jack: 57001-1238

•

Turn the handlebar all the way to the right or left.

•

Hold the front fork leg and move [A] the front wheel side-

ways with force to inspect the roughness of the hub bear-

ing.

•

Spin [B] the front wheel lightly, and check for smoothly

turn, roughness, binding or noise.

If roughness, binding or noise is found, remove the front

wheel and inspect the hub bearing (see Wheels/Tires

chapter).

•

Using a jack, raise the rear wheel off the ground (see

Wheels/Tires chapter).

Special Tool - Jack: 57001-1238

•

Hold the swingarm and move [A] the rear wheel sideways

with force to inspect the roughness of the hub bearing.

•

Spin [B] the front wheel lightly, and check for smoothly

turn, roughness, binding or noise.

If roughness, binding or noise is found, remove the rear

wheel and inspect the wheel bearing (see Wheels/Tires

chapter).

Final Drive

Drive Chain Slack Inspection

•

Raise the rear wheel off the ground.

•

Check the wheel alignment (see Wheel Alignment Inspec-

tion in the Final Drive chapter), and adjust it if necessary

(see Wheel Alignment Adjustment in the Final Drive chap-

ter).

NOTE

○

Clean the drive chain if it is dirty, and lubricate it if it

appears dry.

•

Rotate the rear wheel to find the position where the chain

is tightest (because it wears unevenly).

•

Measure the space (chain slack) [A] between the chain

and the swingarm at the rear of the chain slipper as

shown.

If the drive chain slack exceeds the standard, adjust it.

Chain Slack

Standard: 52 ∼ 62 mm (2.05 ∼ 2.44 in.)

2-30 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Drive Chain Slack Adjustment

•

Loosen the left and right chain adjuster locknuts [A].

•

Remove the cotter pin [B] and loosen the axle nut [C].

If the chain is too tight, turn in the left and right chain

adjusting bolts [D] evenly, and push the wheel forward

until the chain is too loose.

If the chain is too loose, turn out both chain adjusting

bolts evenly until the drive chain has the correct amount

of slack. To keep the chain and wheel properly aligned,

the notch on the left chain adjuster should align with the

same swingarm mark [E] as the right chain adjuster notch

[F].

•

Check the wheel alignment.

•

Tighten both chain adjuster locknuts securely.

•

Tighten the axle nut.

Torque - Rear Axle Nut: 110 N·m (11.0 kgf·m, 80 ft·lb)

•

Rotate the wheel, measure the chain slack again at the

tightest position, and readjust if necessary.

•

Install a new cotter pin [A] through the axle nut and axle,

and spread its ends.

NOTE

○

When inserting the cotter pin, if the slots in the nut do

not align with the cotter pin hole in the axle shaft, tighten

the nut clockwise [B] up to next alignment.

○

It should be within 30 degree.

○

Loosen once tighten again when the slot goes past the

nearest hole.

•

Bend the cotter pin [A] over the nut [B].

WARNING

If the axle nut is not securely tightened, or the cotter

pin is not installed, an unsafe riding condition may

result.

•

Check the rear brake (see Brakes chapter).

NOTE

○

In wet and muddy conditions, mud sticks to the chain

and sprockets resulting in an overly tight chain, and the

chain may break. To prevent this, adjust the chain to 62

∼

72 mm (2.44

∼

2.83 in.) of slack whenever necessary.

PERIODIC MAINTENANCE 2-31

Periodic Maintenance Procedures

Drive Chain Wear Inspection

•

Rotate the rear wheel to inspect the drive chain for dam-

aged rollers, and loose pins and links.

If there is any irregularity, replace the drive chain.

Lubricate the drive chain if it appears dry.

[A] Bushing

[B] Roller

[C] Pin

[D] Pin Link

[E] R oller Link

•

Stretch the chain taut by hanging a 98 N (10 kgf, 20 lb)

weight [A] on the chain.

•

Measure the length of 20 links [B] on the straight part [C] of

the chain from the pin c enter of the 1st pin to the pin center

of the 21st pin. Since the chain may wear unevenly, take

measurements at several places.

Chain 20-link Length

Standard: 317.5 ∼ 318.2 mm (12.50 ∼ 12.53 in.)

Service Limit: 323 m m (12.72 in.)

If any measurements exceed the service limit, replace the

chain. Also, replace the front and rear sprockets when the

drive chain is replaced.

WARNING

If the drive chain wear exceeds the service limit, re-

place the chain or an unsafe riding condition may

result. A chain that breaks or jumps off the sprock-

ets could snag on the engine sprocket or lock the

rear wheel, severely damaging the m otorcycle and

causing it to go out of control.

Standard Chain

Make:

DAIDO

Type: D .I.D 520DMA2

Link: 114 Links

Drive Chain Lubrication

•

If the chain appears especially dirty, it should be cleaned

before lubrication with high flash-point solvent.

•

If a special lubricant is not available, a heavy oil such as

SAE90 is preferred to a lighter oil because it will stay on

the chain longer and provide better lubrication.

•

Apply oil to the sides of the rollers so that oil will penetrate

to the rollers and bushings.

•

Wipe off any excess oil.

Oil applied area [A]

2-32 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Sprocket Wear Inspection

•

Visually inspect the front and rear sprocket teeth for wear

and damage.

If they are worn as illustrated or damaged, replace the

sprocket.

A. Worn Tooth (Engine Sprocket)

B. Worn Tooth (Rear Sprocket)

C. Direction of Rotation

•

Measure the diameter of the sprocket at the base of the

teeth.

If the sprocket is worn down to less than the service limit,

replace the sprocket.

Engine Sprocket Diameter

Standard: 55.48 ∼ 55.68 mm (2.184 ∼ 2.192 in.)/1 3T

Service Limit: 54.8 mm (2.175 in.)

Rear Sprocket Diameter

Standard: 247.64 ∼ 248.14 mm (9.750 ∼ 9.769

in.)/51T

Service Lim it: 24 7.3 mm (9.736 in.)

NOTE

○

If a sprocket requires replacement, the chain is proba-

bly worn also. When replacing a sprocket, inspect the

chain.

Rear Sprocket Warp Inspection

•

Using the jack, raise the rear wheel off the ground.

Special Tool - Jack: 57001-1238

•

Set a dial gauge [A] against the rear sprocket [B] near the

teeth as shown and rotate [C] the rear wheel to measure

the sprocket runout (warp). The difference between the

highest and lowest dial gauge readings is the amount of

runout (warp).

If the runout exceeds the service limit, replace the rear

sprocket.

Rear Sprocket Runout

Standard: TIR 0.4 mm (0.016 in.) or less

Service Lim it: TIR 0.5 mm (0.020 in.)

Brakes

Brake Lever and Pe dal Position Adjustment

WARNING

Always maintain proper brake adjustment. If ad-

justment is improper, the brake could drag and

overheat. This could damage the brake assembly

and possibly lock the wheel resulting in loss of

control.

PERIODIC MAINTENANCE 2-33

Periodic Maintenance Procedures

•

Adjust the front brake lever [A] to suit you.

•

Slide the brake lever dust cover [B] out of place.

•

Loosen the adjuster locknut [C] and turn the adjuster [D]

to either side.

•

After adjustment, tighten the locknut.

NOTE

○

Usually it is not necessary to adjust the pedal position,

but always adjust it when the master cylinder is disas-

sembled or pedal position is incorrect.

•

Measure the length indicated in the figure.

Length [A]

Standard: 68.5 ±1 mm (3.09 ±0.04 in.)

If it is not specified length, the brake pedal may be de-

formed or incorrectly installed.

If it is not within the specified length, adjust the clevis [A]

as following.

○

Loosen the push rod locknut [B].

○

Remove:

Cotter Pin [C]

Washer

Joint Pin [D]

○

Turn the clevis [D] to obtain the specified length.

○

Tighten the locknut.

Torque - Rear Master Cylinder Push Rod Locknut: 18 N·m

(1.8 kgf·m, 13 ft·lb)

○

Install the joint pin and new cotter pin.

2-34 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Brake Fluid Level Inspection

In accordance with the Periodic Maintenance Chart, in-

spect the brake fluid level in the front or rear brake fluid

reservoirs.

•

Check the brake fluid level in the front or rear brake reser-

voir [A].

NOTE

○

Hold the reservoir horizontal when checking brake fluid

level.

○

The front or rear reservoir must be kept above the lower

level line [B]. If the fluid level in front or rear reservoir is

lower than the lower level line, fill the reservoir to the

upper level line. Inside the reservoir is stopped end

showing the upper level line [C].

Torque - Brake Reservoir Cap Screws: 1.5 N·m (0.15 kgf·m,

13 in·lb)

WARNING

Do not mix two brands of fluid. Change the brake

fluid in the brake line completely if the brake fluid

must be refilled but the type and brand of the brake

fluid that is already in the reservoir are unidentified.

After changing the fluid, use only the same type and

brand of fluid thereafter.

PERIODIC MAINTENANCE 2-35

Periodic Maintenance Procedures

Brake Fluid Change

In accordance with the Periodic Maintenance Chart,

change the brake fluid. The brake fluid should also be

changed if it becomes contaminated with dirt or water.

Furthermore, the brake fluid should be changed to bleed

the air quickly and completely whenever the brake line

parts are removed.

WARNING

When working with the disc brake, observe the pre-

cautions listed below.

1. Never reuse old brake fluid.

2. Do not use fluid from a container that has been left

unsealed or that has been open for a long time.

3. Do not mix two types and brands of fluid for use in

the brake. This lowers the brake fluid boiling point

and could cause the brake to be ineffective. It may

also cause the rubber brake parts to deteriorate.

4. Don’t leave the reservoir cap off for any length of

time to avoid moisture contamination of the fluid.

5. Don’t change the fluid in the rain or when a strong

wind is blowing.

6. Except for the disc pads and disc, use only disc

brake fluid, isopropyl alcohol, or ethyl alcohol for

cleaning brake parts. Do not use any other fluid for

cleaning these parts. Gasoline, engine oil, or any

other petroleum distillate will cause deterioration of

the rubber parts. Oil spilled on any part will be diffi-

cult to wash off completely and will eventually dete-

riorate the rubber used in the disc brake.

7. When handing the disc pads or disc, be careful that

no disc brake fluid or any oil gets on them. Clean off

any fluid or oil that inadvertently gets on the pads or

disc with a high-flash point solvent. Do not use one

which will leave an oily residue. Replace the pads

with new ones if they cannot be cleaned satisfacto-

rily.

8. Brake fluid quickly ruins painted surfaces; any

spilled fluid should be completely wiped up imme-

diately.

9. If any of the brake line fittings or the bleed valve is

opened at any time, the AIRMUSTBEBLEDFROM

THEBRAKELINE.

Recommended Disc Brake Fluid

Type:

Front

DOT3 or DOT4

Rear

DOT4

2-36 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

NOTE

○

The procedure to change the front brake fluid. Chang-

ing the rear brake fluid is the same as for the front brake.

•

Level the brake fluid reservoir.

•

Remove the screw [A], reservoir cap [B] and diaphragm

[C].

•

Remove the rubber cap [A] on the bleed valve [B].

•

Attach a clear plastic hose [A] to the bleed valve on the

caliper, and run the other end of the hose into a container

[B].

PERIODIC MAINTENANCE 2-37

Periodic Maintenance Procedures

•

Change the brake fluid as follows:

○

Repeat this operation until fresh brake fluid comes out

from the plastic hose or the color of the fluid changes.

1. Open the bleed valve [A]

2. Apply the brake and hold it [B]

3. Close the bleed valve [C]

4. Release the brake [D]

○

Fill the reservoir with fresh specified brake fluid.

NOTE

○

The fluid level must be checked often during the chang-

ing operation and replenished with fresh brake fluid. If

the fluid in the reservoir runs out any time during the

changing operation, the brakes will need to be bled

since air will have entered the brake line.

•

Remove the clear plastic hose.

•

Tighten the bleed valves, and install the rubber caps.

Torque - Caliper Bleed Valve: 7.8 N·m (0.8 kgf·m, 69 in·lb)

Brake Reservoir Cap Screws: 1.5 N·m (0.15 kgf·m,

13 in·lb)

•

After c hanging the fluid, check the brake for good braking

power, no brake drag, and no fluid leakage.

If necessary, bleed the air from the lines.

WARNING

Do not mix two brands of fluid. Change the brake

fluid in the brake line completely if the brake fluid

must be refilled but the type and brand o f the brake

fluid that is already in the reservoir are unidentified.

Brake Pad Wear Inspection

•

Check the lining thickness and condition of the pads in

each caliper.

If either pad is damaged, replace both pads in the caliper

as a set.

If the lining thickness [A] of either pad is less than the

service limit [B], replace both pads in the caliper as a set.

Lining Thickness

Standard:

Front

3.8 mm (0.150 in.)

Rear

6.4 mm (0.252 in.)

Service Limit:

Front

1 mm (0.04 in.)

Rear

1 mm (0.04 in.)

•

Install the brake pad (see Brake Pad Installation in the

Brakes chapter).

•

Tighten:

Torque - Brake Pad Bolt: 18 N·m (1.8 kgf·m, 13 ft·lb)

2-38 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Brake Master Cylinder Cup and Dust Cover

Replacement

•

Remove the front master cylinder (see Brake chapter).

•

Remove the reservoir cap and diaphragm, and pour the

brake fluid into a container.

•

Unscrew the locknut and pivot bolt, and remove the brake

lever.

•

Pull the dust c over [A] out of place, and remove the circlip

[B].

Special Tool - Ins id e Circl ip Pliers : 57001-143

•

Remove the washer [C].

•

Pull out the piston [D], secondary cup [E], primary cup [F],

and return spring [G].

CAUTION

Do not remove the secondary cup from the piston

since removal will damage it.

•

Remove the rear master cylinder (see Brake chapter).

NOTE

○

Do not remove the push rod clevis for master cylinder

disassembly since removal requires brake pedal posi-

tion adjustment.

•

Remove the reservoir cap and diaphragm, and pour the

brake fluid into a container.

•

Slide the dust cover [A] on the push rod [B] out of place,

and remove the circlip [C].

Special Tool - Ins id e Circl ip Pliers : 57001-143

•

Pull out the push rod with the piston stop [D].

•

Take off the piston [E], secondary cup [F], primary cup [G],

and return spring [H].

CAUTION

Do not remove the secondary cup from the piston

since removal will damage it.

•

Before assembly, clean all parts including the master

cylinder with brake fluid or alcohol.

CAUTION

Except for the disc pads and disc, use only disc

brake fluid, isopropyl alcohol, or ethyl alcohol for

cleaning of the brake parts. Do not use any other

fluid for cleaning of these parts, Gasoline, engine

oil, or any other petroleum distillate will cause de-

terioration of the rubber parts. Oil spilled on any

part will be difficult to wash off completely, and will

eventually deteriorate the rubber used in the disc

brake.

PERIODIC MAINTENANCE 2-39

Periodic Maintenance Procedures

•

Replace the piston, secondary cup, primary cup and

spring as a s et with a new one.

•

Replace the dust cover with a new one.

•

Apply brake fluid to the removed parts and to the inner

wall of the cylinder.

•

Take care not to scratch the piston or the inner wall of the

cylinder.

•

Apply silicone grease (ex. PBC grease).

Brake Lever Pivot Bolt

Brake Lever Pivot Contact

Push Rod Contact (Rear)

Dust Covers

•

Tighten:

Torque - B ra ke Lev er Pivot Bolt: 5.9 N·m (0.6 kgf·m, 52

in·lb)

Caliper Fluid Seal and Dust Seal Replacement

•

Loosen the brake pad pin [A] and banjo bolt [B], and

tighten them loosely.

•

Remove:

Front Caliper Mounting Bolts [C]

Banjo Bolt

Brake Hose [E]

Front Caliper [D] (see Brakes chapter)

Brake Pads (see Brakes chapter)

•

Separate the caliper holder [A] from the caliper [B] and

remove the anti-rattle spring.

•

Using compressed air, remove the pistons. One way to

remove the pistons is as follows.

○

Cover the caliper opening with a clean, heavy cloth [A].

○

Remove the pistons by lightly applying compressed air [B]

to the hose joint opening.

WARNING

To avoid serious injury, never place your fingers or

palm in front of the piston. If you apply compressed

air into the caliper, the piston may crush your hand

or fingers.

2-40 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

○

Pull out the piston [A] by hand.

•

Remove the dust seals [B] and fluid seals [C].

NOTE

○

If compressed air is not available, do as follows for both

calipers coincidentally, with the brake hose connected

to the caliper.

○

Prepare a container for brake fluid, and perform the

work above it.

○

Remove the spring and pads (see Brakes chapter)

○

Pump the brake lever until the pistons come out of the

cylinders, and then disassembly the caliper.

•

Remove the rear caliper (see Brakes chapter).

•

Remove the pads (see Brakes chapter).

•

Separate the caliper holder [B] from the caliper [A].

•

Using compressed air, remove the piston.

○

Cover the caliper opening with a clean, heavy cloth [A].

○

Remove the piston by lightly applying compressed air [B]

to where the brake line fits into the caliper.

WARNING

To avoid serious injury, never place your fingers or

palm inside the caliper opening. If you apply com-

pressed air into the caliper, the piston may crush

your hand or finger.

•

Pull out the piston [A] by hand.

•

Remove the dust seal [B] and fluid seal [C].

•

Clean the caliper parts except for the pads.

CAUTION

For cleaning of the parts, use only disc brake fluid,

isopropyl alcohol, or ethyl alcohol.

•

The bleed valve was removed, install the bleed valve and

rubber cap.

To rque - Bleed Valve: 7.8 N·m (0.80 k gf·m, 69 in·lb)

PERIODIC MAINTENANCE 2-41

Periodic Maintenance Procedures

•

Replace the fluid seal(s) [A] with new ones.

○

Apply brake fluid to the fluid seal(s), and install them into

the cylinders by hand.

•

Replace the dust seal(s) [B] with new ones.

○

Apply brake fluid to the dust seal(s), and install them into

the cylinder by hand.

•

Apply brake fluid to the outside of the pistons [C], and

push them into each cylinder by hand.

•

Install t he anti-rattle spring [A] in the caliper as shown.

2-42 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

•

Replace the shaft rubber boot [A] and dust cover [B] if

they are damaged.

•

Apply a thin coat of PBC (Poly Butyl Cuprysil) grease to

the caliper holder shafts [C] and holder holes (PBC is a

special high temperature, water-resistance grease).

•

Install the pads (see Brakes chapter).

•

Install the caliper (see Brakes chapter).

•

Wipe up any spilled brake fluid on the caliper with wet

cloth.

Brake H ose and Conne ction Check

•

Inspect the brake hose and fittings for deterioration,

cracks and signs of leakage.

○

The high pressure inside the brake line can cause fluid to

leak [A] or the hose to burst if the line is not properly main-

tained. Bend and twist the rubber hose while examining

it.

Replace the hose if any cracks [B] or bulges [C] are no-

ticed.

Tighten any loose fittings.

Brake Hose Replacement

CAUTION

Brake fluid quickly ruins painted surfaces; any

spilled fluid should be completely w ashed away

immediately.

•

When removing the brake hose, take care not to spill the

brake fluid on the painted or plastic parts.

•

When removing the brake hose temporarily secure the

end of the brake hose to some high place to keep fluid

loss to a minimum.

•

Immediately wash away any brake fluid that spills.

PERIODIC MAINTENANCE 2-43

Periodic Maintenance Procedures

•

Remove each banjo bolts [A] and washers [B].

•

Replace the washers with new ones.

For Front Brake

•

Remove

Bolts [A]

Brake Hose Clamps [B]

For Rear Brake

•

Remove:

Master Cylinder [A]

Hose Clamps [B]

Caliper Cover [C]

Rear Wheel [D]

Rear Caliper [E]

•

When installing the hoses, avoid sharp bending, kinking,

flattening or twisting, and route the hoses according to

Cable, Wire, and Hose Routing section in the Appendix

chapter.

•

Tighten the banjo bolts on the hose fittings.

Torque - Bra ke Hose Banjo Bolts: 25 N·m (2.5 kgf·m, 18

ft·lb)

•

Fill the brake line after installing the brake hose (see

Brake Fluid Changing).

2-44 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Suspension

Front Fork Inspection

•

Holding the brake lever, compress the front fork several

times to check for smooth operation.

•

Visually inspect the front fork for oil leakage, scoring or

scratches on the outer surface of the inner tube [A].

If necessary, repair any damage.

•

Nick or rust damage can sometimes be repaired by using

a wet-stone to remove sharp edges or raised areas which

cause seal damage.

If the damage is not repairable, replace the inner tube.

Since damage to the inner tube damages the oil seal,

replace the oil seal whenever the inner tube is repaired

or replaced.

•

If the fork is not smooth, confirm the cause.

CAUTION

If the inner tube is badly bent or creased, replace

it. Excessive bending, followed by subsequent

straightening, can weaken the inner tube.

Front Fork Oil Change (each fork leg)

•

Loosen the front fork upper clamp bolts [A].

•

Loosen the fork top plug (subtank) [A] with the special

tool.

Special Tool - Top Plug Wrench, 46 mm: 57001-1622 [B]

•

Remove the front fork (see Front Fork Removal).

NOTE

○

Set rebound and compression damping setting to the

softest settings before disassembling to p revent the

needle of adjusters from damaging. Record the setting

before turning the adjuster.

•

Thoroughly clean the fork before disassembly.

CAUTION

Be careful not scratch the i nner tube and not to

damage the dust seal.

Avoid scratching or damaging the inner tube or the

dust seal. Use a mild detergent and sponge out dirt

with plenty of water.

PERIODIC MAINTENANCE 2-45

Periodic Maintenance Procedures

•

Using the special tool [A], remove the fork top plug [B]

(subtank) from the outer tube and slowly slide down the

outer tube [C].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

•

Place a drain pan under the front fork and drain fork oil

[A].

NOTE

○

Pump the fork tube several times to discharge the fork

oil.

•

Raise the outer tube and temporarily install the fork top

plug [A] (subtank) to the outer tube [B] with the special

tool [C].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

•

Hold the axle holder [A] with a vise.

○

Protect the axle holder with a rag when using a vise.

•

Loosen the adjuster assembly [B] completely.

WARNING

Clamping the axle holder too tight can damage it

which will affect riding stability.

Do not clamp the axle holder too tight.

•

Compress the outer tube by hands and install the top plug

wrench (special tool) [A] between the axle holder bottom

and lock nut.

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

WARNING

Be careful of reaction force in spring and fix surely

so that the special tool should not come off. Do not

place the finger etc. while servicing.

2-46 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

•

Hold the locknut [A] with a wrench [B] and remove the

adjuster assembly [C].

•

Remove the push rod [A].

•

With the outer tube compressed by hands, remove the

top plug wrench (special tool) [A].

CAUTION

Removing the lock nut and pushing the piston rod

thread into the cylinder unit will damage the oil seal.

Do not remove the lock nut from the piston rod.

•

Remove the f ork leg from the vise.

•

Loosen the fork top plug (subtank) with the special tool

[A].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622 [B]

•

Remove:

Cylinder Unit [A]

Spring Collar [B] (KX250-R1)

Fork Spring [C]

Spring Collar [D]

CAUTION

Disassembling the cylinder unit can lead to trouble.

Do not disassemble the cylinder unit.

PERIODIC MAINTENANCE 2-47

Periodic Maintenance Procedures

•

Holding the top plug wrench [A] with a vise, loosen the

base valve assembly [B] on the subtank [C].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622 [B]

•

Remove the base valve assembly [A] from the subtank

[B].

NOTE

○

Slowly compress the piston rod until it stops so that the

base valve assembly can be removed easily.

CAUTION

Disassembling the base valve assembly can lead to

trouble.

Do not disassemble the base valve assembly.

•

Drain the fork oil [A] from the cylinder unit [B] by pumping

the piston rod several times

•

Hold the front fork inverted position for more than 20 min-

utes to allow the fork oil to fully drain.

•

Clean the threads [A] of subtank and base valve assem-

bly.

2-48 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

•

With the piston rod in fully compressed position, pour the

specified amount of fork oil [A].

Recommended Oil: KHL15-10 (KAYABA01) or

equivalent

Recommended Quantity: 160 ml (5.41 US oz.)

NOTE

○

Plug the two oil holes [B] on the subtank [C] with fingers.

•

Pump [A] the piston rod [B] slowly several times to expel

air.

•

Replace the O-rings [A] on the base valve assembly with

new ones.

•

Apply specified fork oil to the O-rings [A] [B] and bushings

[C] on the base valve assembly.

•

With the piston rod held immorable in fully compressed

position [A], gently install the base valve assembly [B] to

the s ubtank.

•

Screw in the base valve assembly in the subtank when

the piston rod extends.

NOTE

○

When it is hard to screw in the base valve assembly,

pull down the piston rod a little.

PERIODIC MAINTENANCE 2-49

Periodic Maintenance Procedures

•

Holding the top plug wrench [A] (special tool) with a vise.

•

Holding the subtank [B] with the top plug wrench, torque

the base valve assembly [C].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

Torque - Base Valve Assembly: 27 N·m (2.8 kgf·m, 20 ft·lb)

•

Protect the piston rod end [A] with a rag [B] to prevent fork

damage.

•

Discharge the extra oil off the cylinder unit by pumping [C]

the piston rod to full stroke.

CAUTION

Be careful not to bend or damage the piston rod

when the piston rod is stroked. Service carefully

because oil flies out from the oil hole of the cylinder

unit.

NOTE

○

Set the compression damper setting to the softest.

○

Check the piston rod sliding surface for damage.

○

Apply fork oil to the piston rod sliding surface.

•

Drain the extra oil from the subtank oil hole [A].

•

With the cylinder unit in horizontal position, move [A] the

piston rod [B] by hand to inspect it if operating smoothly.

○

If the piston rod is not extend, remove the base valve

assembly and perform the air bleeding (pour the specified

amount fork oil and discharge an excess of oil).

2-50 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

•

Make sure about 16 mm (0.63 in.) [A] of push rod thread

is exposed from the lock nut [B].

•

Completely wipe of the fork oil from the following parts.

Cylinder Unit [A]

Spring Collar [B] (KX250-R1)

Fork Spring [C]

Spring Collar [D]

•

Insert above-mentioned parts into the fork.

•

Temporarily tighten the fork top plug [A] (subtank) using

the special tool.

Special Tool - Top Plug Wrench, 46 mm: 57001-1622 [B]

•

Clamp the axle holder with a vise.

○

Protect the axle holder with a rag when using a vise.

WARNING

Clamping the axle holder too tight can damage it

which will affect riding stability.

Do not clamp the axle holder too tight.

•

Compress the outer tube by hands and install the top plug

wrench [A] (special tool) between the axle holder bottom

and lock nut.

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

WARNING

Be careful of reaction force in spring and fix surely

so that special tool should not come off.

Do not place the fingers etc. while serving.

PERIODIC MAINTENANCE 2-51

Periodic Maintenance Procedures

•

Insert the push rod [A] into the piston rod.

•

Replace the O-ring and gasket on the adjuster assembly

with new ones and apply specified fork oil to the O-ring.

•

Slowly turn the adjuster assembly [A] clockwise until re-

sistance is felt and check the clearance between the lock

nut [B] and adjuster assembly [A] to provide more than 1

mm (0.04 in.) [C].

•

Turn the lock nut [A] counterclockwise until it contacts with

the adjuster assembly [B].

•

With the lock nut held immovable using a wrench, tighten

the adjuster assembly to the specified torque.

Torque - Lock Nut/Adjuster Assembly: 29 N·m (3.0 kgf·m,

22 ft·lb)

•

With the outer tube compressed by hands, remove the

special tool.

•

Apply a non-permanent locking agent to the threads of a

adjuster assembly.

•

Torque the adjuster assembly.

Torque - Adjuster Assembly: 58 N·m (6.0 kgf·m, 43 ft·lb)

•

Loosen and remove the fork top plug (subtank) form the

outer tube and slowly slide down the outer tube.

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

•

Pour [A] the specified amount of fork oil into the outer

tube.

Recommended Oil: KHL15-10 (KAYABA01) or

equivalent

Recommended Quantity:

KX250-R1: 300 mL (10.14 US oz.)

KX250-R2 ∼: 310 mL (10.48 US oz.)

2-52 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

•

Raise the outer tube and temporarily tighten the fork top

plug (subtank).

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

•

After installing the front fork, torque the top plug [A].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622 [B]

The torque of fork top plug is specified to 29 N·m (3.0

kgf·m, 22 ft·lb) however, when you use the top plug wrench

(special tool) [A], reduce the torque to 90% of the spec-

ified value [26 N·m (2.7 kgf·m, 20 ft·lb)] due to the dis-

tance [B] between the center of the s quare hole, where the

torque wrench is fitted, and that of the octagonal hole of the

wrench.

This torque value [26 N·m (2.7 kgf·m, 20 ft·lb)] is appli-

cable when you use a torque wrench whose length gives

leverage of approximately 310 mm between the grip point

to the center of the coupling square.

Rear Shock Absorber Inspection

•

Bounce [A] the rear of the motorcycle up and down and

check for smooth suspension stroke.

•

Lift the rear frame (see Carburetor Removal in the Fuel

System).

•

Check for a broken or collapsed spring.

•

Check the shock for a bent shaft or oil leaks.

If the shock does not smoothly or damaged, replace or

repair defective parts.

Rear Shock Absorber Oil Change

The oil s hould be changed in the rear shock absorber at

least once per racing season. The frequency for best per-

formance must be based upon riding conditions and rider

ability.

•

Remove the rear shock absorber from the frame (see

Suspension chapter).

•

Remove the shock absorber spring (see Suspension

chapter).

•

Point the valve [A] away from you. Slowly release nitro-

gen gas pressure by pushing down the valve core with a

screw driver.

WARNING

Do not to point the reservoir valve toward your face

or body when releasing nitrogen gas pressure. An

oil mist is often released with the nitrogen. Always

release nitrogen gas pressure before disassem-

bling the rear shock absorber to prevent explosive

separation of parts.

PERIODIC MAINTENANCE 2-53

Periodic Maintenance Procedures

•

Adjust the gas reservoir damping adjusters [A] to the soft-

est position.

•

Remove the air bleeder bolt [B] and pump the rear shock

to drain the oil out the rear shock body.

•

Install the air bleeder bolt.

•

Using the suitable tool [A] and press, push the reservoir

cap [B] in 10 mm (0.39 i n.).

•

Remove the circlip [C] from the gas reservoir.

•

Pull the gas reservoir cap [B] out of the gas reservoir using

the pliers [A].

•

Pry or tap [A] at the gaps [B] in the stop [C] with suitable

tools to free the stop from the rear shock body [D].

•

Slide the stop up the top of the piston rod then lightly tap

around the seal with a s uitable rod and mallet, and push

the seal assembly 10 mm (0.39 in.) down.

•

Remove the circlip [A].

•

Lightly move the piston rod back and forth, and pull out

the piston rod assembly.

•

Pour the oil out of the rear shock body.

2-54 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

•

Visually inspect the piston [A], O-ring [B], and oil seal assy

[C].

•

If the piston, O-ring and oil seal assy are badly scored,

rusty or damaged, replace them.

•

Using the grinder, shave off the stopper portion [A] of the

rod.

•

Remove:

Nut [B]

Washer [C]

Piston [D]

•

Install the new piston and tighten the locknut.

○

Discard a washer or two.

•

Pour KYB K2-C oil into the gas reservoir to 60 ∼ 70 mm

(2.63 ∼ 2.76 in.) [A] from the gas reservoir upper end.

•

Check that the bladder [A] on the gas reservoir cap is not

partially collapsed.

If it is, push down the valve core with a screwdriver.

•

Check the bladder for sign of damage or crack.

If necessary, replace it with a new one.

CAUTION

Do not use a damaged or partially collapsed blad-

der, because it may burst, gently reducing rear

shock performance. .

•

Apply grease to the lip [B] of the bladder and install the

reservoir cap [C].

•

Push the bladder into the gas reservoir slowly until it just

clears the circlip groove. Wipe out any spilled oil.

CAUTION

Ensure that no air remains in the system.

PERIODIC MAINTENANCE 2-55

Periodic Maintenance Procedures

•

Check the circlip for weakening, deformity and flaws.

If necessary, replace it with a new one.

CAUTION

If weakened, deformed or flawed circlip is used, the

gas reservoir cap may not hold when injecting the

nitrogen gas. This would allow oil and internal parts

to explode out of the reservoir.

•

Mount the circlip [A] in the groove in the gas reservoir.

•

Pull up the gas reservoir cap [A] against the circlip. The

end of the gas reservoir cap must align [B] with the end

of the gas reservoir [C].

WARNING

If the end of the gas reservoir cap and the end of

the gas reservoir are not aligned, the circlip is not

correctly fitting in the groove in the gas reservoir or

is deformed. In this case, the oil and internal parts

could explode out of the reservoir when injecting

the nitrogen gas or while riding the motorcycle.

•

Pour KYB K 2-C oil into the rear shock body to 55 mm

(1.77 in.) [A] from the lower end of the rear shock body

[B].

2-56 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

•

Insert the piston end [A] of the piston rod assembly into

the rear shock body [C] slowly. Do not insert the seal

assembly [B] yet. Pump the piston rod until all the air is

forced out of the rear shock body.

•

Push the seal assembly into the rear shock body until it

just clears the circlip groove.

•

Check the circlip.

If it is deformed or damaged, replace it with a new one.

•

Fit the circlip [A] into the groove in the rear shock body

[B].

CAUTION

If the circlip is not a certain fit in the groove in the

rear shock body, the piston rod assembly may come

out of the shock absorber when injecting th e nitro-

gen gas or riding the motorcycle.

•

Pull up the piston rod assembly [C] against the circlip.

•

Force the stop [D] into the rear shock body by lightly tap-

ping around the edge of the stop with a m allet.

•

Fully extend the piston rod assembly.

•

Install the suitable oil cup [A] to the air bleeder bolt hole,

and fill the specified oil into the cup.

•

Purge the air from between the gas reservoir [B] and rear

shock body [C] by slowly pumping the push rod [D] in and

out.

•

Install the air bleeder bolt securely.

To rque - Air Bleeder Bolt: 6.4 N·m (0.65 kgf·m, 5 6 in·lb)

•

Fully extend the push rod assembly.

•

Inject nitrogen gas to a pressure of 50 kPa (0.5 kgf/cm²,

7 psi) through the valve on the gas reservoir.

•

Check the rear shock body and gas reservoir for oil and

gas leaks.

If there are no leaks, inject the nitrogen gas up to the 980

kPa (10 kgf/cm², 142 psi) pressure.

WARNING

Pressurize the gas reservoir with nitrogen gas only.

Do not use air or other gases, since they may cause

premature wear, rust, fire hazard or substandard

performance.

High pressure gas is dangerous. Have a qualified

mechanic perform this procedure.

•

Install the spring and spring guide.

•

Adjust spring preload. Reinstall the rear shock absorber.

•

Install the parts removed.

PERIODIC MAINTENANCE 2-57

Periodic Maintenance Procedures

Swingarm and Uni-Trak Linkage Inspection

•

Check the uni-trak component parts for wear periodically,

or whenever excessive play is suspected.

•

Using the jack under the frame, raise the rear wheel off

the ground.

Special Tool - Jack: 57001-1238

•

Push and pull on the swingarm [A], up and down, to check

for wear.

A small amount of play on the swingarm is normal and no

corrective action is needed. However, if excessive play is

felt, remove the uni-trak parts f rom the frame and check

for wear.

Swingarm and Uni-Track Linkage Pivot Lubricate

•

Refer to the Swingarm Bearing Installation and Rocker

Arm Bearing Installation i n Suspension chapter.

Chain Guide Wear Inspection

•

Visually inspect the drive chain guide [A] and replace it if

excessively worn or damaged.

Chain Slipper Wear Inspectio n

•

Visually inspect the upper and lower chain slippers [A] on

the swingarm [B] and replace them if worn or damaged.

Steering

Steering Inspection

•

Using the jack, raise the front wheel off the ground.

Special Tool - Jack: 57001-1238

•

With the front wheel pointing straight ahead, alternately

nudge each end of the handlebar. The front wheel should

swing fully left and right from the force of gravity until the

fork hits the stop.

If the steering binds or catches before the stop, check the

routing of the cables, hoses, and harnesses.

If the steering feels tight, adjust or lubricate the steering.

•

Feel for steering looseness by pushing and pulling the

forks.

If you feel looseness, adjust the steering.

Steering Adjustment

•

Using the jack, raise the front wheel off the ground.

Special Tool - Jack: 57001-1238

2-58 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

KX250-R1:

•

Remove:

Number Plate [A]

Handlebar Holder Bolts [B]

Handlebar Holder [C]

Handle Bar [D]

•

Pull out the breather hose [E].

KX250R6F ∼:

•

Remove:

Number Plate [A]

Pad [B]

Handlebar Holder Bolts [C]

Handlebar Holders (Upper) [D]

Handlebar [E]

•

Pull out the breather hose [F].

•

Loosen the front fork upper clamp bolts [A], and remove

the steering stem head nut [B] and steering stem head

[C].

•

Turn the steering stem nut [A] with the steering stem nut

wrench [B] to obtain the proper adjustment.

If the steering is too tight, loosen the stem nut a fraction

of a turn; if the steering is too loose, tighten the stem nut

a fraction of a turn.

Special Tool - Steering Stem Nut Wrench: 57001-1100

NOTE

○

Turn the stem nut 1/8 turn at a time maximum.

•

Install the steering stem head.

•

Tighten the following:

Torque - Steering Stem Head Nut: 98 N·m (10.0 kgf·m, 72

ft·lb)

Upper Front Fork Clamp Bolts: 20 N·m (2.0 kgf·m,

14.5 ft·lb)

NOTE

○

Tighten the two clamp bolts alternately two times to en-

sure even tightening torque.

•

Check the steering again.

If the steering is too tight or too loose, repeat the adjust-

ment as mentioned above.

PERIODIC MAINTENANCE 2-59

Periodic Maintenance Procedures

KX250-R1:

•

Install the handlebar [A] on the handlebar holder as

shown.

Same Length [B]

Bridge Bar [C]

•

Install the handlebar holder [A] together with the handle-

bar so that the mark side [B] on the holder points at the

rear.

•

Tighten the handlebar holder bolts [C].

Torque - Handlebar Holder Bolts: 25 N·m (2.5 kgf·m, 18

ft·lb)

○

Tighten the holder bolts, front first and then the rear. If the

handlebar holder is correctly installed, there will be no gap

at the front and a gap [D] at the rear after tightening.

•

Install the number plate.

KX250R6F ∼:

•

Install the handlebar [A] on the handlebar holder as

shown.

Same Length [B]

Bridge Bar [C]

Protrusion of Graduation [D]

•

Install the handlebar holders. [A] with handlebar.

○

Tighten the front and rear bolts [B] of the handlebar

equally.

If the handlebar holders are correctly installed, there will

be same amount of gap [C] on the front and rear side of

the clamp after the bolts tightening.

Torque - Handlebar Holder Bolts: 25 N·m (2.5 kgf·m, 18

ft·lb)

•

Install:

Pad

Number Plate

2-60 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Stem Bearing Lubrication

•

Remove the steering stem (see Steering Stem Removal

in Steering chapter).

•

Using a high-flash-point solvent, wash the upper and

lower tapered rollers in the cages, and wipe the upper

and lower outer races, which are press-fitted into the

frame head pipe, clean off grease and dirt.

•

Visually check the outer races and the rollers.

Replace the bearing assemblies if they show wear or

damage.

•

Pack the upper and lower tapered roller bearings [A] in

the cages with grease, and apply a light coat of grease to

the upper and lower outer races.

•

Install the steering stem, and adjust the steering (see

Steering chapter).

Frame

Frame Inspection

•

Clean the frame with steam cleaner.

•

Visually inspect the frame and rear frame for cracks,

dents, bending, or warp.

If there is a ny damage to the frame, replace it.

WARNING

A repaired frame may fail in use, possibly causing

an accident. If the frame is bent, dented, cracked,

or warped, replace it.

Electrical System

Spark Plug Cleaning and Inspection

•

Remove:

Seat (see Frame chapter)

Fuel Tank (see Fuel System chapter)

Spark Plug Cap

•

Clean the cylinder head and area around the spark plug,

using the compressed air [A].

•

Remove the spark plug [A], using the spark plug wrench

[B].

Special Tool - Spark Plug Wrench: 57001-110

Owner’s Tool - Spark Plug Wrench, 16 mm: 92110-1200

•

Clean the spark plug, preferably in a sandblasting device,

and then clean off any abrasive particles. The plug may

also be cleaned using a high-flash-point solvent and a

non-wire brush.

CAUTION

Do not use wire brush when cleaning the spark plug

to prevent the platinum electrode damage.

If the spark plug electrodes are corroded or damaged,

or if the insulator is cracked, replace the plug. Use the

standard spark plug.

PERIODIC MAINTENANCE 2-61

Periodic Maintenance Procedures

•

Measure the gap [A] with a wire-type thickness gauge to

prevent possible damage to the platinum electrode.

If the gap is incorrect, replace it with the standard plug.

Spark Plug Gap

Standard: 0.7 ∼ 0.8 mm (0.028 ∼ 0.031 in.)

•

Install the spark plug.

Torque - Spark Plug: 26 N·m (2.7 kgf·m, 20 ft·lb)

•

Fit the plug cap securely.

○

Pull the spark plug cap [A] to make sure the installation of

the spark plug cap.

General Lubrication

Lubrication

•

Before lubricating each part, clean off any rusty spots with

rust remover and wipe off any grease, oil, dirt, or grime.

•

Lubricate the points listed below with indicated lubricant.

NOTE

○

Whenever the vehicle has been operated under

wet or rainy conditions, or especially after using a

high-pressure water spray, perform the general lubri-

cation.

Pivots: Lubricate with Engine Oil

Clutch Lever

Brake Lever

Kick Pedal

Shift Pedal

Rear Brake Rod Joint

Drive Chain

Rear Brake Rod Joint Pin

Points: Lubricate with Grease.

Clutch Inner Cable Upper End [A]

Throttle Inner Cable Upper End

Swingarm Pivot

Tie-Rod Pivot

Rocker Arm Pivot

Steering Stem Bearing

2-62 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Cables: Lubricate with Cable Lubricant

Throttle Cables

Clutch Cable

•

Lubricate the cables by seeping the oil between the inner

cable and cable housing.

○

The cable may be lubricated by using a commercially

available pressure cable lubricator with an aerosol cable

lubricant.

•

With the cable disconnected at the both ends, the cable

should move freely [A] within the cable housing.

If cable movement is not free after lubricating, if the c able

is frayed [B], or if the cable housing is kinked [C], replace

the cable.

PERIODIC MAINTENANCE 2-63

Periodic Maintenance Procedures

Nut, Bolt, and Fastener Tightness

Tightness Inspection

•

Check the tightness of bolts and nuts listed here. Also,

check to s ee that each cotter pin is in place and in good

condition.

NOTE

○

For the engine fasteners, check the tightness of them

when the engine is cold (at room temperature).

If there are loose fasteners, retorque them to the spec-

ified torque following the specified tightening sequence.

Refer to the appropriate chapter for torque specifications.

If torque specifications are not in the appropriate chapter,

see the Standard Torque Table. For each fastener, first

loosen it by 1/2 turn, then tighten it.

If cotter pins are damaged, replace them with new ones.

Nut, Bolt and Fastener to be checked

Wheels:

Spoke N ipples

Front Axle Nut

Rear Axle Nut Cotter P in

Rear Axle Nut

Final Drive:

Chain Adjuster Locknuts

Rear Sprocket Nuts

Brakes:

Front Master Cylinder Clamp Bolts

Caliper Mounting Bolts (Front)

Rear Master Cylinder Mounting Bolts

Rear Master Cylinder Joint Cotter Pin

Brake Lever Pivot Nut

Brake Pedal Bolt

Suspension:

Front Fork Clamp Bolts

Front Fender Mounting Bolt

Rear Shock Absorber Mounting Nuts

Swingarm Pivot Shaft Nut

Uni-Trak Link Nuts

Steering:

Steering Stem H ead Nut

Handlebar Holder Bolts

Engine:

Engine Mounting Nuts

Engine Bracket Nuts

Cylinder Head Nuts

Shift Pedal Bolt

Muffler Bolt and Nut

Kick Pedal Bolt

Others:

Rear Frame Mounting Bolts

FUEL SYSTEM 3-1

Fuel System

Table of Contents

Exploded View........................................................................................................................ 3-2

Specifications ......................................................................................................................... 3-6

Special Tool ............................................................................................................................ 3-7

Throttle Grip and Cable .......................................................................................................... 3-8

Free Play Inspection ......................................................................................................... 3-8

Free Play Adjustment ........................................................................................................ 3-8

Throttle Cable Installation ................................................................................................. 3-8

Throttle Cable Lubrication................................................................................................. 3-8

Carburetor .............................................................................................................................. 3-9

Idle Speed Inspection ....................................................................................................... 3-9

Idle Speed Adjustment...................................................................................................... 3-9

Service Fuel Level Inspection ........................................................................................... 3-9

Service Fuel Level Adjustment ......................................................................................... 3-10

Carburetor Removal.......................................................................................................... 3-11

Carburetor Installation....................................................................................................... 3-13

Fuel Inspection..................................................................................................................3-13

Carburetor Disassembly ................................................................................................... 3-14

Carburetor Assembly ........................................................................................................ 3-16

Carburetor Cleaning.......................................................................................................... 3-16

Carburetor Inspection ....................................................................................................... 3-16

Air Cleaner.............................................................................................................................. 3-18

Air Cleaner Housing Removal........................................................................................... 3-18

Air Cleaner Housing Installation........................................................................................ 3-18

Element Removal .............................................................................................................. 3-18

Element Installation ........................................................................................................... 3-19

Element Cleaning and Inspection ..................................................................................... 3-19

Fuel Tank................................................................................................................................ 3-20

Fuel Tank Removal ........................................................................................................... 3-20

Fuel Tank Installation ........................................................................................................ 3-20

Fuel Tap Removal ............................................................................................................. 3-21

Reed Valve ............................................................................................................................. 3-22

Reed Valve Removal ........................................................................................................ 3-22

Reed Valve Installation ..................................................................................................... 3-22

Reed Valve Inspection ...................................................................................................... 3-22

3-2 FUEL SYSTEM

Exploded View

FUEL SYSTEM 3-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Carburetor Top Cover Allen Bolts 3.9 0.40 35 in·lb

2 Reed Valve Screws 1.0 0.10 8.8 in·lb

3 Carburetor Holder Mounting Bolts 8.8 0.90 78 in·lb

Carburetor Holding Clamp Screw

1.5 0.15 13 in·lb

5. Throttle Cable

6. Throttle Grip

7. Spring

8. Retainer

9. Connector

10. Jet Needle Clip

11. Jet Needle

12. Throttle Valve

13. Choke Knob

14. Idle Adjusting Screw

15. Spring

16. Air Screw

17. Slow Jet

18. Power Jet

19. Main Jet

20. Float Valve Needle

21. Float

22. Throttle Sensor

23. Fuel Cut Valve

24. Carburetor Holder

25. Reed Valve

G: Apply grease.

O: Apply oil.

2T: Apply 2 stroke oil.

3-4 FUEL SYSTEM

Exploded View

FUEL SYSTEM 3-5

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Air Cleaner Duct Clamp Screw 1.5 0.15 13 in·lb

2 Air Cleaner Duct Mounting Nut 3.0 0.30 27 in·lb

3 Air Cleaner Housing B olts 8.8 0.90 78 in·lb

4 Rear Frame Mounting Bolts 34 3.5 25

5. Fuel Tank Cap

6. Fuel Tank

7. Fuel Tap

8. Element

9. Frame

10. Holder

11. Air Cleaner Duct

12. Air Cleaner Housing

13. Rear Frame

G: Apply grease.

O: High-quality foam-air-filter oil.

3-6 FUEL SYSTEM

Specifications

Item Standard Service Limit

Carburetor

Make/Type KEIHIN PWK38S –––

Main Jet: #160 –––

Power Jet: #55

Throttle Valve Cutaway #8

–––

Jet Needle NFTG –––

Jet Needle C lip Position 2nd groove from the top

SlowJet(PilotJet) #50 –––

Air Screw (Turns Out) 11/2 –––

Service Fuel Level 10.5 ±1 mm (0.413 ±0.039 in.) –––

(above the Bottom Edge of

the Carburetor Body)

Float Height 6.5 ±1 mm (0.256 ±0.039 in.) –––

Fuel Cut Valve see Electrical System chapter

Throttle Sensor see Electrical System chapter

FUEL SYSTEM 3-7

Special Tool

Fuel Level Gauge, M18 × 1.0:

57001-122

3-8 FUEL SYSTEM

Throttle Grip and Cable

If the throttle grip has excessive free play due to cable

stretch or misadjustment, there will be a delay in throttle re-

sponse. Also, the throttle valve may not open fully at full

throttle. On the other hand, if the throttle grip has no play,

the throttle will be hard to control, and the idle speed will

be erratic. Check the throttle grip play periodically in accor-

dance with the Periodic Maintenance Chart, and adjust the

play if necessary.

The throttle cable routing is shown in Cable, Wire and

Hose Routing in the Appendix chapter.

Free Play Inspection

•

RefertotheThrottleGripFreePlayInspectioninthePe-

riodic Maintenance chapter.

Free Play Adjustment

•

Refer to the Throttle Grip Free Play Adjustment in the

Periodic Maintenance chapter.

Throttle Cable Installation

•

Install the throttle cable in accordance with the Cable,

Wire and Hose Routing i n the Appendix chapter.

•

After the installation, adjust each cable properly.

WARNING

Operation with an incorrectly routed or improperly

adjusted cable could result in an unsafe riding con-

dition.

Throttle Cable Lubrication

•

Refer to the General Lubrication in the Periodic Mainte-

nance chapter.

FUEL SYSTEM 3-9

Carburetor

Since the carburetor regulates and mixes the fuel and air

going to the engine, there are two general types of carbure-

tor trouble: too rich a mixture (too much fuel), and too lean

a mixture (too little fuel). Such trouble can be caused by

dirt, wear, maladjustment, or improper fuel level in the float

chamber. A dirty or damaged air cleaner can also alter the

fuel to air ratio.

Idle Speed Inspection

•

Refer to the Idle Speed Inspection in the Periodic Main-

tenance chapter.

Idle Speed Adjustment

•

Refer to the Idle Speed Adjustment in the Periodic Main-

tenance chapter.

Service Fuel Level Inspection

WARNING

Gasoline is extremely flammable and can be ex-

plosive under certain conditions. Always stop the

engine and do not smoke. Make sure the area is

well ventilated and free from any source of flame

or sparks; this includes any appliance with a pilot

light.

•

Turn the fuel tap to the OFF position.

•

Remove the fuel tank.

•

Remove the c arburetor, and hold it in true vertical position

on a stand. The fuel hose and carburetor cable do not

have to be removed to inspect the fuel level [A].

•

Put the fuel tank on a bench, and connect the fuel tap to

the carburetor using a suitable hose.

•

Remove the drain plug from the bottom of the float bowl,

and screw a fuel level gauge [B] into the plug hole.

Special Tool - Fuel Level Gauge, M18 × 1.0: 57001-122

3-10 FUEL SYSTEM

Carburetor

•

Hold the gauge vertically against the side of the carbure-

tor body so that the “zero” line [C] is several millimeters

higher than the bottom edge [D] of the carburetor body.

•

Turn the fuel tap to the ON position to feed fuel to the

carburetor.

•

Wait until the fuel level in the gauge settles.

•

Keeping the gauge vertical, slowly lower the gauge until

the “zero” line is even with the bottom edge of the carbu-

retor body.

NOTE

○

Do not lower the “zero” line below the bottom edge of

the carburetor body. If the gauge is lowered and then

raised again, the fuel level measure shows somewhat

higher than the actual fuel level. If the gauge is lowered

too far, dump the fuel out of it into a suitable container

and start the procedure over again.

•

Read the fuel level in the gauge and compare it to the

specification.

Service Fuel Level (above the bottom edge of the

carburetor body)

Standard: 10.5 ±1 mm (0.413 ±0.039 in.)

If the fuel level is incorrect, adjust it.

•

Turn the fuel tap to the OFF position and remove the fuel

level gauge.

•

Install the drain plug on the bottom of the float bowl.

Service Fuel Level Adjustment

WARNING

Gasoline is extremely flammable and can be ex-

plosive under certain conditions. Always stop the

engine and do not smoke. Make sure the area is

well-ventilated and free from any source of flame

or sparks; this includes any appliance with a pilot

light.

•

Remove the carburetor, and drain the fuel into a suitable

container.

•

Remove the float bowl.

•

Drive out the pivot pin [A] and remove the float [B].

FUEL SYSTEM 3-11

Carburetor

•

Bend the tang [A] on the float arm very slightly to change

the float height. Increasing the float height lowers the fuel

level and decreasing the float height raises the fuel level.

Float Height

Standard: 6.5 ±1 mm (0 .256 ±0.039 in.)

NOTE

○

Float height [A] is the distance from the float bowl mat-

ing surface [B] of the carburetor body (with the gasket

removed) to the top of the float [C]. Measure the height

with the c arburetor upside down.

○

Do not push the needle rod [D] in during the float height

measurement.

•

Assemble the c arburetor, and recheck the fuel level.

If the fuel level cannot be adjusted by this method, the

float or the float valve is damaged.

Carburetor Removal

WARNING

Gasoline is extremely flammable and can be ex-

plosive under certain conditions. Always stop the

engine and do not smoke. Make sure the area is

well-ventilated and free from any source of flame

or sparks; this includes any appliance with a pilot

light.

•

Turn the fuel tap to the OFF position and pull the fuel hose

off the tap.

•

Remove the fuel tank and left shroud.

•

Disconnect the carburetor lead connector [A].

3-12 FUEL SYSTEM

Carburetor

•

Loosen the clamps [A].

•

Remove:

Right Side Cover

Muffler

Rear Frame Bolts [A] (Left and Right)

○

Loosen the rear frame bolts [B], pull up the rear frame [C]

with the air cleaner housing and remove the carburetor.

•

Drain the fuel from the float bowl by removing the drain

plug. After draining, install the drain plug securely.

•

Unscrew the carburetor cap bolts [A].

•

Pull out the throttle valve assembly [A].

CAUTION

If the throttle valve is not removed from the cable,

wrap it in a clean cloth to avoid damage.

•

After removing the carburetor, push a clean, lint-free towel

into the carburetor holder and the air cleaner duct to keep

dirt or other foreign material from entering.

WARNING

If dirt or dust is allowed to pass through into the

carburetor, the throttle may become stuck, possibly

causing an accident.

CAUTION

If dirt gets through into the engine, excessive en-

gine wear and possibly engine damage will occur.

FUEL SYSTEM 3-13

Carburetor

Carburetor Installation

•

Lifting up the link shaft end [A] of the throttle sensor install

the throttle valve assembly.

•

Being careful not to bend or otherwise damage the jet

needle. Check to see that the throttle valve [B] goes all the

way down into the carburetor body, and slides smoothly.

•

When installing the carburetor into the carburetor holder,

align the center [A] of the carburetor with the groove [B]

on the holder.

•

Tighten the clamps securely.

•

Route the air vent and overflow hoses properly (see Ap-

pendix chapter).

CAUTION

Always keep the hoses free of obstruction, and

make sure they do not get pinched by the chain or

shock absorber.

•

Connect the carburetor lead connector.

•

After installing the carburetor, do the following.

○

Turn the fuel tap to the ON position, and check for fuel

leakage from the carburetor.

WARNING

Fuel spilled from the carburetor is hazardous.

○

Adjust the following items if necessary:

Throttle Cable

Idle Speed

Fuel Inspection

WARNING

Gasoline is extremely flammable and can be ex-

plosive under certain conditions. Always stop the

engine and do not smoke. Make sure the area is

well-ventilated and free from any source of flame

or sparks; this includes any appliance with a pilot

light.

3-14 FUEL SYSTEM

Carburetor

•

Turn the fuel tap to the OFF position.

•

Remove the carburetor.

•

Place a suitable container beneath the carburetor.

•

Remove the drain plug [A] from the bottom of the float

bowl and check for water or dirt in the fuel.

If any water or dirt comes out, clean the carburetor, fuel

tap and fuel tank (see this chapter).

•

Install the drain plug on the float bowl, and tighten it se-

curely.

•

Install the carburetor.

Carburetor Disassembly

•

Remove the carburetor.

•

Unscrew the carburetor top cap bolts [A].

•

Pull out the throttle valve assembly.

•

Remove the throttle valve assembly [A], spring [B], re-

tainer [C] and carburetor cap from the carburetor cable

lower end.

•

Disassemble the throttle valve assembly; connector [A],

jet needle with circlip [B] and throttle valve [C].

•

Remove the choke knob/starter plunger assembly [A]

from the carburetor.

FUEL SYSTEM 3-15

Carburetor

•

Remove the fuel cut valve [A] from the carburetor.

•

Remove the throttle sensor mounting bolt [A].

•

Before removing the throttle sensor [B], mark [C] the car-

buretor body and sensor so that it can be installed later in

the same position.

•

Remove the throttle sensor link assembly screws [A].

•

Remove the link assembly [B].

•

Remove the following parts from the carburetor body.

[A] Idle Adjusting Screw

[B] Spring

[C] Air Screw

[D] Spring

[E] Slow Jet

[F] Main Jet

[G] Float Valve Needle

[H] Float

[I] Pin

[J] O-ring

[K] Float Bowl

[L] Power Jet

3-16 FUEL SYSTEM

Carburetor

Carburetor Assembly

•

Clean the disassembly parts before assembling.

•

Replace the O-rings with a new one if it is deteriorated or

damaged.

•

Turn in the air screw [A] fully but not tightly, and then back

it out the specified number of turns. (see Specifications

of this chapter)

•

Install the throttle sensor so that the marks aligns and

check it position (see Electrical System chapter).

Carburetor Cleaning

WARNING

Clean the carburetor in a well-ventilated area, and

take care that there is no spark or flame anywhere

near the working area; this includes any appliance

with a pilot light. Because of the danger of highly

flammable liquids, do not use gasoline or low flash

-point solvent to clean the carburetor.

•

Make sure the fuel tap is in the OFF position.

•

Remove the carburetor.

•

Drain the fuel in the carburetor.

•

Disassemble the carburetor.

CAUTION

Do not use compressed air on an assembled carbu-

retor, the float may be deformed by the pressure.

Remove as many rubber or plastic parts from the

carburetor as possible before cleaning the carbu-

retor with a cleaning solution. This will prevent

damage or deterioration of the parts. Do not use

a strong carburetor cleaning solution which could

attack the plastic parts; instead, use a mild high

flash-point cleaning solution safe for plastic parts.

Do not use wire or any other hard instrument to

clean carburetor parts, especially jets, as they may

be damaged.

•

Immerse all the metal parts in a carburetor cleaning solu-

tion.

•

Rinse the parts in water.

•

After the parts are cleaned, dry them with compressed air.

•

Blow through the air and fuel passages with compressed

air.

•

Assemble the carburetor, and install it on the motorcycle.

Carburetor Inspection

WARNING

Gasoline is extremely flammable and can be ex-

plosive under certain conditions. Always stop the

engine and do not smoke. Make sure the area is

well-ventilated and free from any source of flame

or sparks; this includes any appliance with a pilot

light.

FUEL SYSTEM 3-17

Carburetor

•

Remove the carburetor.

•

Before disassembling the carburetor, check the fuel level

(see Fuel Level Inspection).

If the fuel level is incorrect, inspect the rest of the carbu-

retor before correcting it.

•

Pull the carburetor cable to check that the throttle valve

[A] moves smoothly and returns by spring pressure.

If the throttle valve does not move smoothly. Replace the

carburetor.

•

Disassemble the carburetor.

•

Clean the carburetor.

•

Check the O-rings on the float bowl, pilot screw, and throt-

tle sensor are in good condition.

If any of the O-rings are not in good condition, replace

them.

•

Check the tapered portion [A] of the pilot screw [B] for

wear or damage.

If the pilot screw is worn or damaged on the tapered por-

tion, it will prevent the engine from idling smoothly. Re-

place it.

•

Remove the float valve needle.

•

Check the plastic tip [A] of the float valve needle [B] for

wear.

If the needle is worn as shown right [C], replace the valve

needle.

•

Push the rod [D] in the valve needle, then release it.

If the rod does not come out fully by spring tension, re-

place the valve needle.

Push and release [E]

•

Remove the slow jet.

•

Check the slow jet for any damage.

If the slow jet is damaged, replace it with a new one.

•

Remove the throttle valve and jet needle.

•

Inspect the outside of the throttle valve for scratches and

abnormal wear.

If it is badly scratched or worn, replace the throttle valve.

•

Inspect the inside of the carburetor body for these same

faults.

If it is badly scratched or worn, replace the entire carbu-

retor.

•

Check the jet needle for wear.

A worn jet needle should be replaced.

•

Clean the fuel and air passages with a high flash-point

solvent and compressed air.

3-18 FUEL SYSTEM

Air Cleaner

Air Cleaner Hou s ing Removal

•

Remove:

Side Covers (see Frame chapter)

Seat (see Frame chapter)

Muffler (see E ngine Top End chapter)

Bolts and Rear Fender [A] (see Frame chapter)

Screws and Rear Flap [B] (see Frame chapter)

Rear Frame M ounting Bolts [C]

•

Loosen the air cleaner duct clamp [D].

•

Remove the rear frame.

•

Unscrew the bolt [A].

•

Remove the air cleaner housing [B].

Air Cleaner Housing I nstallation

•

Installation is the reverse of the removal.

•

Install the air cleaner housing and tighten it.

Torque - Air Cleaner Housing Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

•

Tighten the rear frame mounting bolts.

Torque - Rear Frame Mounting Bolts: 34 N·m (3.5 kgf·m, 25

ft·lb)

Element Removal

•

Remove the seat.

•

Remove the wing bolt [A] and pull out the element [B].

•

Stuff a clean, lint-free towel into the carburetor so no dirt

is allowed to enter the carburetor.

•

Wipe out the inside of the air cleaner housing with a clean

damp towel.

CAUTION

Check inside of the inlet tract and carburetor for

dirt. If dirt is present, clean the intake tract and car-

buretor thoroughly. You may also need to replace

the element and seal the housing and inlet tract.

FUEL SYSTEM 3-19

Air Cleaner

Element Installation

•

When installing the element, coat the lip of the element

with a thick layer of all purpose grease [A] to assure a

complete seal against the air cleaner element base. Also,

coat the base where the lip of the element fits.

•

Apply grease to all connections and screw holes in the air

cleaner housing and intake tract.

•

Take out the towel from the carburetor securely.

•

Install the element so that its tab [A] faces upward and fit

the element projections [B] to the holes of the housing [C].

•

Tighten the wing bolt [D].

•

Install the seat (see Frame chapter).

Element Cleaning and Inspection

•

Refer to the Air Cleaner Element Cleaning and Inspection

in the Periodic Maintenance chapter.

3-20 FUEL SYSTEM

Fuel Tank

Fuel Tank Removal

WARNING

Gasoline is extremely flammable and can be ex-

plosive under certain conditions. Always stop the

engine and do not smoke. Make sure the area is

well-ventilated and free from any source of flame

or sparks; this includes any appliance with a pilot

light.

•

Remove:

Seat [A] (see Frame chapter)

Bolts [B]

Radiator Shrouds [C]

•

Turn the fuel tap lever [A] to the OFF position.

•

Slide out the clamp [B] and pull the fuel hose [C] off the

fuel tap [D].

•

Remove the fuel tank mounting bolt [A] and band [B].

•

Pull out the fuel tank breather hose [C].

•

Remove the fuel tank [D].

•

Drain the fuel.

Fuel Tank Installation

•

Check the rubber dampers [A] on the frame.

If the dampers are damaged or deteriorated, replace

them.

•

Be sure the fuel hose is clamped to the fuel tap to prevent

leaks.

•

Insert the fuel tank breather hose outlet end into the steer-

ing stem hole (see Appendix chapter).

FUEL SYSTEM 3-21

Fuel Tank

Fuel Tap Removal

•

Remove the fuel tank and drain it.

•

Remove the mounting bolts [A] and take out the fuel tap

[B].

3-22 FUEL SYSTEM

Reed Valve

Reed Valve Removal

•

Remove the carburetor.

•

Remove the holder mounting bolts [A], and take off the

carburetor holder [B].

•

Take the reed valve [A] out of the cylinder.

Reed Valve Installation

•

Tighten the carburetor holder mounting bolts.

Torque - Carburetor Holder Mounting Bolts: 8.8 N·m (0.90

kgf·m, 78 in·lb)

Reed Valve Inspection

•

Refer to the Reed Valve Inspection in the Periodic Main-

tenance chapter.

COOLING SYSTEM 4-1

Cooling System

Table of Contents

Exploded View........................................................................................................................ 4-2

Specifications ......................................................................................................................... 4-4

Special Tool ............................................................................................................................ 4-5

Coolant ................................................................................................................................... 4-6

Coolant Level Inspection ................................................................................................... 4-6

Coolant Deterioration Inspection....................................................................................... 4-6

Coolant Draining ............................................................................................................... 4-6

Coolant Filling ................................................................................................................... 4-6

Air Bleeding....................................................................................................................... 4-6

Cooling System Pressure Testing ..................................................................................... 4-6

Cooling System Flushing .................................................................................................. 4-7

Disassembly and Assembly Precautions................................................................................ 4-8

Water Pump............................................................................................................................ 4-9

Water Pump Cover Removal ............................................................................................ 4-9

Water Pump Cover Installation ........................................................................................ 4-9

Impeller R emoval .............................................................................................................. 4-9

Impeller Installation ........................................................................................................... 4-9

Impeller Inspection............................................................................................................ 4-10

Water Pump Shaft Removal ............................................................................................. 4-10

Water Pump Shaft Installation .......................................................................................... 4-10

Oil Seal Removal .............................................................................................................. 4-10

Oil Seal Installation ........................................................................................................... 4-11

Radiator.................................................................................................................................. 4-12

Radiator Removal ............................................................................................................. 4-12

Radiator Installation .......................................................................................................... 4-12

Radiator Inspection ........................................................................................................... 4-13

Cap Inspection .................................................................................................................. 4-13

Filler Neck Inspection........................................................................................................ 4-14

Cooling Hoses, Breather Hose Inspection ........................................................................ 4-14

Cooling Hoses, Breather Hose Installation ....................................................................... 4-14

4-2 COOLING SYSTEM

Exploded View

COOLING SYSTEM 4-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Water Pump Cover Bolts 8.8 0.90 78 in·lb

2 Water Pump Cover Fitting Bolts 8.8 0.90 78 in·lb

3 Coolant Drain Plug 8.8 0.90 78 in·lb

4 Water Pump Impeller Bolt 6.9 0.70 61 in·lb

5 Right Engine Cover Bolts 8.8 0.90 78 in·lb

6 Radiator Shroud Bolts 8.8 0.90 78 in·lb

7 Radiator Mounting Bolts 8.8 0.90 78 in·lb

8 Radiator Screen Bolts 8.8 0.90 78 in·lb

9 Radiator Bracket Bolts 8.8 0.90 78 in·lb

10 Cooling Hose Clamp Screws 1.5 0.15 13 in·lb

11. Radiator

12. Radiator Cap

13. Water Pump Cover

14. Impeller

15. Oil Seal (Short)

16. Oil Seal (Long)

17. Bearing

18. Water Pump Gear

19. Right Engine Cover

20. Cylinder Head

21. Cylinder

G: Apply grease.

M: Apply m olybdenum disulfide grease.

R: Replacement Part

4-4 COOLING SYSTEM

Specifications

Item Service Limit

Coolant

Type Permanent type antifreeze for aluminum engines and radiators

Color Green

Mixed Ratio Soft water 50%, antifreeze 50%

Total Amount

1.20 L (1.27 US qt.)

Radiator

Cap Relief Pressure 93 ∼ 123 kPa (0.95 ∼ 1.25 kgf/cm², 13 ∼ 18 psi)

COOLING SYSTEM 4-5

Special Tool

Bearing Driver Set:

57001-1129

4-6 COOLING SYSTEM

Coolant

Check the coolant level each day before riding the motor-

cycle, and replenish coolant if the level is low. Change the

coolant in accordance with the Periodic Maintenance Chart

(see Periodic Maintenance chapter).

WARNING

To avoid burns, do not remove the radiator cap

or try to inspect the coolant level or change the

coolant when the engine is still hot. Wait until it

cools down.

Coolant Level Inspection

•

Refer to the Coolant Level Inspection in the Periodic Main-

tenance chapter.

Coolant Deterioration Inspection

•

Refer to the Coolant Deterioration Inspection in the Peri-

odic Maintenance chapter.

Coolant Draining

•

Refer to the Coolant Draining in the Periodic Maintenance

chapter.

Coolant Filling

•

Refer to the Coolant Filling in the Periodic Maintenance

chapter.

Air Bleeding

•

Refer to the Air Bleeding in the Periodic Maintenance

chapter.

Cooling S ystem Pressure Testing

CAUTION

During pressure testing, do not exceed the pres-

sure for which the system is designed to work. The

maximum pressure is 123 kPa (1.25 kgf/cm², 18 psi).

•

Remove the radiator cap, and install a cooling system

pressure tester [A] and adapter [B] on the radiator filler

neck [C].

NOTE

○

Wet the adapter cap sealing surfaces with water or

coolant to prevent pressure leaks.

•

Builduppressureinthesystemcarefullyuntilthepres-

sure reaches 123 kPa (1.25 kgf/cm², 18 psi).

•

Watch the gauge for at least 6 seconds. If the pressure

holds steady, the cooling system i s all right.

•

Remove the pressure tester, replenish the coolant, and

install the radiator cap.

If the pressure drops and no external source is found,

check for internal leaks. Check the cylinder head gasket

for leaks.

COOLING SYSTEM 4-7

Coolant

Cooling System Flushing

Over a period of time, the cooling system accumulates

rust, scale, and lime in the water jacket and radiator. When

this accumulation is suspected or observed, flush the cool-

ing system. If this accumulation is not removed, it will clog

up the water passages and considerably reduce the effi-

ciency of the cooling system.

•

Drain the cooling system.

•

Fill the cooling system with fresh water mixed with a flush-

ing compound.

CAUTION

Avoid the use of a flushing compound which is

harmful to the aluminum engine and radiator.

Carefully follow the instructions supp lied by the

manufacture of the cleaning product.

•

Warm up the engine, and run it at normal operating tem-

perature for about ten minutes.

•

Stop the engine, and drain the cooling system after the

coolant cools down.

•

Fill the system with fresh water.

•

Warm up the engine and drain the system after the

coolant cools down.

•

Repeat the previous two steps once more.

•

Fill the system with a permanent type coolant, and bleed

the air from the system (see Air Bleeding).

4-8 COOLING SYSTEM

Disassembly and Assembly Precautions

•

Prior to disassembly of cooling system parts (radiator,

pump, etc), wait until the coolant cools down, and then

drain the coolant.

•

After assembling and filling the system with coolant, bleed

any air from the system.

COOLING SYSTEM 4-9

Water Pump

Water Pump Cover Removal

•

Drain the coolant (see Coolant Draining).

•

Loosen the cooling hose clamps [A], and disconnect the

cooling hoses on the water pump cover [B].

•

Unscrew the cover bolts [C], and remove the water pump

cover.

Water Pump Cover Installation

•

Replace the pump cover gasket [A] with a new one.

•

Be sure the dowel pins [B] are in position.

•

Tighten the water pump cover bolts.

Torque - Water Pump Cover Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

•

Install the hose clamp [A] as shown and tighten the clamp

screw securely.

Torque - Cooling Hose Clamp Screws: 1.5 N·m (0.15 kgf·m,

13 in·lb)

Impeller Removal

•

Drain the coolant (see Coolant Draining).

•

Remove the cover bolts and hose, and take out the water

pump cover from the right engine cover.

•

Remove the impeller bolt [A], and take out the impeller [B]

and washer.

Impeller Installation

•

Tighten the impeller bolt.

Torque - Water Pump Impeller Bolt: 6.9 N·m (0.70 kgf·m, 61

in·lb)

4-10 COOLING SYSTEM

Water Pump

Impeller Inspection

•

Visually check the impeller [A].

If the surface is corroded, or if the blades [B] are dam-

aged, replace the impeller.

Water Pump Shaft Removal

•

Remove:

Right Engine Cover (see Engine Right Side chapter)

•

Pull out the water pump shaft [A] toward inside of the right

engine cover.

Water Pump Shaft Installation

•

To prevent the oil seal lips from peeling, apply a molybde-

num disulfide grease [A] to the water pump shaft [B] and

insert it into the oil seals [C] from the inside of the right

engine cover [D].

CAUTION

Be sure to apply a molybdenum disulfide grease

to the water pump shaft when installing. If it is in-

stalled dry, the seals may wear excessively.

•

Instal the impeller and check to see that the impeller turn

freely.

Oil Seal Removal

•

Remove:

Right Engine Cover (see Engine Right Side chapter)

Water Pump Shaft

•

Insert a bar [A] into the water pump shaft hole from the

outside of the right engine cover, and remove the ball

bearing [B] by tapping [C] evenly around the bearing in-

ner race.

COOLING SYSTEM 4-11

Water Pump

•

Insert a bar [A] into the water pump shaft hole from the

inside of the right engine cover, and remove the oil seal

[B] by tapping [C] evenly around the seal lips.

Oil Seal Installation

CAUTION

If the oil seal or ball bearing is removed, replace all

of them with new ones at the same time

•

Be sure to replace the oil seals.

•

Apply plenty of high temperature grease to the oil seal lips

[A].

•

Press the oil s eals [B] into the hole from the outside of the

right engine cover.

Special Tool - Bearing Driver Set: 57001-1129 [C]

•

Set the oil seal (thick) so that dual lips side face outward

and set the oil seal (thin) so that a lip faces outward as

shown.

NOTE

○

Use a bearing driver larger in diameter than the oil seal,

and press the oil seal into the hole until the edge of the

oil seal faces [D] the surface of right engine cover.

•

Press the ball bearing into the hole until the bearing is

bottomed against the step [E].

Special Tool - Bearing Driver Set: 57001-1129

4-12 COOLING SYSTEM

Radiator

Radiator Removal

•

Drain the coolant (see Coolant Draining)

•

Remove:

Radiator Shrouds

Fuel Tank (see Fuel System chapter)

•

Unscrew the clamps [A] and the bolts [B].

•

Remove the radiator screens [C].

•

Unscrew the bolts [A].

•

Remove:

Radiator Brackets [B]

Radiator [C] with the cooling hoses

Radiator Installation

•

Radiator installation is the reverse of removal.

•

Tighten:

Torque - Cooling Hose Clamp Screws: 1.5 N·m (0.15 kgf·m,

13 in·lb)

Radiator Bracket Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

Radiator Mounting Bolts 8.8 N·m (0.90 kgf·m, 78

in·lb)

Radiator Screen Bolts 8.8 N·m (0.90 kgf·m, 78

in·lb)

Radiator Shroud Bolts 8.8 N·m (0.90 kgf·m, 78

in·lb)

•

Route the cooling and breather hoses correctly.

COOLING SYSTEM 4-13

Radiator

Radiator Inspection

•

Check the radiator core.

If there are obstructions to air flow, remove them.

If the corrugated fins are deformed, carefully straighten

them with the thin blade of a screwdriver [A].

CAUTION

Do not tear the radiator tubes while straightening

the fins.

If the air passages of the radiator core are blocked more

than 20% by unremovable obstructions or irreparably de-

formed fins, replace the radiator with a new one.

CAUTION

When cleaning the radiator with steam cleaner, be

careful of the following to prevent radiator damage.

Keep the steam gun [C] away more than 0.5 m (1.64

ft) [B] from the radiator core. Hold the steam gun

perpendicular to the core surface. Run the steam

gun following the core fin direction [A].

Cap Inspection

•

Check the condition of the valve spring [B], and the top

and bottom valve seals [A] of the radiator cap.

If any one of them shows visible damage, replace the cap.

•

Wet the top and bottom valve seals with water or coolant

to prevent pressure leaks.

•

Install the cap [A] on a cooling system pressure tester [B].

•

Watching the pressure gauge, slowly pump the pressure

tester to build up the pressure. The gauge hand must

remain within the relief pressure range in the table below

at least 6 seconds. Continue to pump the tester until the

relief valve opens, indicated by the gauge hand flicking

downward. The relief valve must open within the specified

range.

Radiator Cap Relief Pressure:

Standard: 93 ∼ 123 kPa (0.95 ∼ 1.25 kgf/cm², 13 ∼ 18 psi)

If the cap cannot hold the pressure, or if the relief pressure

is too high or too low, replace the cap with a new one.

4-14 COOLING SYSTEM

Radiator

Filler Neck Inspection

•

Check the radiator filler neck for signs of damage.

•

Check the condition of the top and bottom sealing seats

[A] in the filler neck. They must be smooth and clean for

the radiator cap to function properly.

Cooling Hoses, Breather Hose Inspection

•

Refer to the Cooling Hoses and Connections Inspection

in the Periodic Maintenance chapter.

Cooling Hoses, Breather Hose Installation

•

Install the cooling hoses or breather hose being careful

to follow the performed bends (see Appendix chapter).

Avoid sharp bending, kinking, flattening, or twisting.

•

Tighten the hose clamps s ecurely.

ENGINE TOP END 5-1

Engine Top End

Table of Contents

Exploded View........................................................................................................................ 5-2

Specifications ......................................................................................................................... 5-4

Special Tools .......................................................................................................................... 5-5

Cylinder Head......................................................................................................................... 5-6

Cylinder Compression Measurement................................................................................ 5-6

Cylinder Head Removal .................................................................................................... 5-6

Cylinder Head Installation ................................................................................................. 5-7

Cylinder Head Warp Inspection ........................................................................................ 5-7

Cylinder .................................................................................................................................. 5-8

Cylinder Removal.............................................................................................................. 5-8

Cylinder Installation........................................................................................................... 5-8

Piston Removal................................................................................................................. 5-9

Piston Installation..............................................................................................................5-10

Cylinder Wear Inspection.................................................................................................. 5-11

Piston Diameter Measurement ......................................................................................... 5-11

Piston/Cylinder Clearance ................................................................................................ 5-11

Piston Ring, Piston Ring Groove Inspection ..................................................................... 5-11

Piston Ring End Gap Inspection ....................................................................................... 5-11

Piston, Piston Pin, Connecting Rod Wear Inspection ....................................................... 5-11

Exhaust Valve (KIPS) ............................................................................................................. 5-12

Exhaust Valve Removal .................................................................................................... 5-12

Exhaust Valve Installation ................................................................................................. 5-13

Muffler (Expansion Chamber, Muffler Body)........................................................................... 5-18

Muffler Removal................................................................................................................ 5-18

Muffler Installation.............................................................................................................5-18

Muffler Baffle Change ....................................................................................................... 5-19

5-2 ENGINE TOP END

Exploded View

ENGINE TOP END 5-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

Main Exhaust Valve Cover Bolts

5.9 0.60 52 in·lb

2 Retaining Plate Bolts 5.9 0.60 52 in·lb

3 Subexhaust Valve Cover B olts 8.8 0.90 78 in·lb

Cylinder Head Nuts:

KX250-R1 25 2.5 18

KX250R6F ∼ 31 3.2 23

with 2.3 mm

washer

Engine Mounting Bracket Nuts (Frame

Side8mm)

29 3.0 22

Engine Mounting Bracket Nuts (Engine

Side 10 mm)

49 5.0 22

7 KIPS Cover Bolts 5.9 0.60 52 in·lb

Governor Shaft Lever Mounting Bolt

5.9 0.60 52 in·lb

9 Sublever Allen Bolt 3.9 0.40 35 in·lb L

10 Main Lever Allen Bolt 3.9 0.40 35 in·lb L

Stopper Pin A llen Bolt

3.9 0.40 35 in·lb L

12 Cylinder Nuts 33 3.4 25

13 Muffler Damper Mounting Bolt 8.8 0.90 78 in·lb

14 Expansion Chamber Mounting Bolt 12 1.2 8.7

15 Muffler Mounting Bolts 8.8 0.90 78 in·lb

16 Muffler Pipe Mounting Bolts 8.8 0.90 78 in·lb L

17 Inner Pipe Mounting Bolts 8.8 0.90 78 in·lb L

18. Main Exhaust Valve Cover

19. Subexhaust Valves

20 Subexhaust Valve Covers

21. Cylinder Head

22. KIPS Cover

23. Engine Mounting Brackets

24. Spring

25. Governor Shaft Lever

26. Subexhaust Valve (Right Side)

27. Main Exhaust Valve

28. Exhaust Valve Shaft

29. Subexhaust Valve (Left Side)

30. Cylinder

31. Stopper Pin

32. Piston Rings

33. Piston

34. Piston Pin

35. IN Mark

36. Expansion Chamber

37. Springs

38. Connecting Seal

39. Muffler Body

40. Reed Valve

G: Apply g rease.

L: Apply a non-permanent locking agent.

M: Apply molybdenum disulfide grease.

O: Apply 2-stroke engine oil.

R: Replacement Part

SS: Apply silicone sealant.

A: KX250-R1 Model

B: KX250R6F Model ∼

5-4 ENGINE TOP END

Specifications

Item Standard Service Limit

Cylinder Head

Cylinder Compression (Usable range) –––

825 ∼ 1 275 kPa (8.4 ∼ 13.0 kgf/cm², 119

∼ 185 psi)

Cylinder Head Warp ––– 0.03 mm (0.0012 in.)

Cylinder, Piston

Cylinder Inside Diameter 66.400 ∼ 66.415 mm (2.6142 ∼ 2.6148 in.) 66.46 mm (2.617 in.)

30 mm (1.18 in.) below of the

cylinder head)

Piston Diameter 66.336 ∼ 66.351 mm (2.6116 ∼ 2.6122 in.) 66.19 mm (2.6059 in.)

Piston/Cylinder Clearance 0.049 ∼ 0.079 mm (0.0019 ∼ 0.0031 in.)

–––

Piston Ring/Groove Clearance 0.025 ∼ 0.06 mm (0.00098 ∼ 0.00236 in.) 0.16 mm (0.006 in.)

Piston Ring Groove Width 1.01 ∼ 1.03 mm (0.0398 ∼ 0.0406 in.) 1.11 mm (0.044 In.)

Piston Ring Thickness 0.970 ∼ 0.985 mm (0.0382 ∼ 0.0388 in.) 0.90 mm (0.035 in.)

Piston Ring End Gap 0.25 ∼ 0.45 mm (0.0098 ∼ 0.0177 in.) 0.75 mm (0.030 in.)

Piston Pin Diameter 17.995 ∼ 18.000 mm (0.7085 ∼ 0.7087 in.) 17.96 mm (0.707 in.)

Piston Pin Hole Diameter

18.001 ∼ 18.011 mm (0.7087 ∼ 0.7091 in.) 18.08 mm (0.712 in.)

Small End Inside Diameter 22.003 ∼ 22.012 mm (0.8663 ∼ 0.8666 in.) 22.05 mm (0.868 in.)

ENGINE TOP END 5-5

Special Tools

Compression Gauge, 20 kgf/cm²:

57001-221

Piston Pin Puller Assembly:

57001-910

Compression Gauge Adapter, M14 × 1.25:

57001-1159

5-6 ENGINE TOP END

Cylinder Head

Cylinder Compression Measurement

•

Start the engine.

•

Thoroughly warm up the engine so that the engine oil be-

tween the piston and cylinder wall will help seal compres-

sion as it does during normal running.

•

Stop the engine.

•

Remove the fuel tank (see Fuel System chapter).

•

Remove the spark plug, and screw a compression gauge

firmly into the spark plug hole.

Special Tools - Compression Gauge, 20 kgf/cm²: 57001-221

[A]

Compression Gauge Adapter, M14 × 1.25:

57001-1159 [B]

•

With the throttle fully open, turn the engine over sharply

with the kickstarter several times until the compression

gauge stops riding; the compression is the highest read-

ing obtainable.

Cylinder Compression

Usable Range:

825 ∼ 1275kPa(8.4∼ 13.0 kgf/cm², 119

∼ 185 psi)

If cylinder compression is higher than the usable range,

check the following:

1. Carbon build up on the piston head and cylinder head -

clean off any carbon on the piston head.

2. Cylinder head gasket, cylinder base gasket - use only

the proper gaskets for the cylinder head and base. The

use of gasket of the incorrect thickness will change the

compression.

If cylinder compression is lower than the usable range,

check the following:

1. Piston/cylinder clearance, piston seizure.

2. Gas leakage around the cylinder head - replace the

damaged gasket and check the cylinder head for warp-

ing.

3. Piston ring, piston ring groove.

Cylinder Head Removal

•

Drain the coolant (see Cooling System chapter).

•

Remove:

Radiator Shrouds

Seat

Side Covers

Fuel Tank (see Fuel System chapter)

Cooling Hose [A]

Spark Plug [B]

Bolts & Nuts [C]

Engine Mounting Brackets [D]

ENGINE TOP END 5-7

Cylinder Head

•

Remove the cylinder head nuts [A], and take off the cylin-

der head [B] and the O-rings.

Cylinder Head Installation

•

Scrape out any carbon and clean the head with a high

flash-point solvent.

•

Check for a crust of minerals and rust in the head water

jacket, and remove them if necessary.

•

Install new O-rings [A] to the grooves of the cylinder se-

curely.

•

Be sure the dowel pins [B] are in position.

CAUTION

Do not reuse the old cylinder head bolt washers.

•

Release the cylinder head bolt washers with new ones.

•

Temporarily tighten the head nuts diagonally.

Torque - Cylinder Head Nuts: 9.8 N·m (1.0 kgf·m, 87 in·lb)

•

Tighten the head nuts diagonally.

Torque - Cylinder Head Nuts:

KX250-R1: 25 N·m (2.5 kgf·m, 18 ft·lb)

KX250R6F ∼: 31 N·m (3.2 kgf·m, 23 ft·lb) with

2.3 mm washer

•

Tighten the engine mounting bracket nuts.

Torque - Engine Mounting Bracket Nuts:

10 mm: 49 N·m (5.0 kgf·m, 36 ft·lb)

8mm:29N·m(3.0kgf·m,22ft·lb)

•

Tighten the spark plug.

Torque - Spark Plug: 26 N·m (2.7 kgf·m, 20 ft·lb)

Cylinder Head Warp Inspe ction

•

Refer to the Cylinder Head Warp Inspection in the Peri-

odic Maintenance c hapter.

5-8 ENGINE TOP END

Cylinder

Cylinder Removal

•

Drain the coolant (see Cooling System chapter).

•

Remove the cylinder head (see this chapter).

•

Remove the cooling hoses.

•

Unscrew the KIPS cover bolts [A] and remove the KIPS

cover [B].

•

Remove:

Bolt [A] and Spring [B]

Governor Shaft Lever [C]

•

Remove the magneto l ead and the clutch cable from

clamp.

•

Remove the cylinder nuts [A].

•

Lift off the cylinder, and remove the cylinder base gasket.

If necessary, tap lightly around the base of the cylinder

with a plastic mallet [A], taking care not to damage the

cylinder.

•

Remove the exhaust valves from the cylinder (see Ex-

haust Valve Removal).

Cylinder Installation

•

Scrape any c arbon out of the exhaust port.

•

Check on a crust of minerals and rust in the cylinder water

jacket, and remove them if necessary.

•

Replace the cylinder base gasket with a new one.

•

Apply 2-stroke engine oil to the piston surface, piston

rings and cylinder bore.

ENGINE TOP END 5-9

Cylinder

•

Check to see that the pin [A] in each piston ring groove

is between the ends of the piston ring, and fit the base of

the cylinder over each ring, pressing in on opposite sides

of the ring as necessary. Be certain that the rings do not

slip out of position.

•

Tighten the cylinder nuts diagonally.

Torque - Cylinder Nuts: 33 N·m (3.4 kgf·m, 25 ft·lb)

•

Set the spring [A] as shown.

[B] Governor Shaft Lever

[C] Exhaust Valve Shaft

•

Using a 14 mm open-end wrench [D], install the governor

shaft lever [B] as shown.

•

Tighten:

Torque - Governor Shaft Lever Mounting Bolt [B]: 5.9 N·m

(0.60 kgf·m, 52 in·lb)

NOTE

○

Put a screw driver ( 6 mm) [F] on the hollow of cylin-

der as shown to prevent the lever link portion [G] from

bending.

•

Install the KIPS cover.

•

Install the removed parts.

Piston Removal

•

Remove the cylinder.

•

Stuff a clean cloth into the crankcase opening around the

connecting rod so that no parts will fall into the crankcase.

•

Remove one of the piston pin snap rings with needle nose

pliers.

•

Remove the piston by pushing the piston pin out the side

from which the snap ring was removed. Use a piston pin

puller assembly [A], if the pin is tight.

Special Tool - Piston Pin Puller Assembly: 57001-910

•

Remove the piston ring(s).

○

Carefully spread the ring [A] opening with your thumbs

and then push up on the opposite side of the ring to re-

move it.

5-10 ENGINE TOP END

Cylinder

Piston Installation

•

Stuff a clean cloth into the crankcase opening around the

connecting rod so that no parts will fall into the crankcase.

•

Scrape off any carbon of the piston, then lightly polish the

piston with fine emery cloth.

•

Clean carbon and dirt out of the piston ring groove using

a suitable tool.

CAUTION

Carbon particles can be very abrasive to piston

ring. Don’t allow such particles to fall onto the

cylinder walls.

•

When installing the piston ring on the piston, note the fol-

lowing:

○

The top [A] and second [B] rings are identical.

○

First fit one end of the piston ring against the pin in the

ring groove, spread the ring opening with the other hand

and then slip the ring into the groove.

○

Install the ring so that the pin [A] in the piston ring groove

is between the ends of the piston ring.

•

Apply 2-stroke engine oil to the connecting rod needle

bearing and the piston pin.

•

Install the piston so that the “IN” marked side [A] faces the

back side of the engine.

•

When installing a piston pin snap ring [A], compress it only

enough to install it and no more.

CAUTION

Do not reuse snap rings, as removal weakens and

deforms them. They could fall out and score the

cylinder wall.

•

Fit a new piston pin snap ring into the side of the piston so

that the ring opening [B] does not coincide with the notch

[C] in the edge of the piston pin hole.

ENGINE TOP END 5-11

Cylinder

Cylinder Wear Inspection

•

Refer to the Cylinder Wear Inspection in the Periodic

Maintenance chapter.

Piston Diameter Measurement

•

Refer to the Piston Diameter Measurement in the Periodic

Maintenance chapter.

Piston/Cylinder Clearance

•

Refer to the Piston/Cylinder Clearance i n the Periodic

Maintenance chapter.

Piston Ring, Piston Ring Gro ove Inspection

•

Refer to the Piston Ring, Piston Ring Groove Inspection

in the Periodic Maintenance chapter.

Piston Ring End Gap Inspection

•

Refer to the Piston Ring End Gap Inspection in the Peri-

odic Maintenance c hapter.

Piston, Piston Pin, Connecting Rod Wear Inspection

•

Refer to the Piston, Piston Pin, Connecting Rod Wear

Inspection in the Periodic Maintenance chapter.

5-12 ENGINE TOP END

Exhaust Valve (KIPS)

Exhaust Valve Removal

•

Remove:

Carburetor (see Fuel System chapter)

Cylinder Head (see Cylinder Head Removal)

KIPS Cover (see Cylinder Removal)

Bolt [A] and Spring [B]

Governor Shaft Lever [C]

•

Remove:

Cylinder (see Cylinder Removal)

Main Exhaust Valve Cover Bolts [A]

Main Exhaust Valve Cover [B] and Gasket

KX250-R1:

•

Remove:

Subexhaust Valve Cover B olts [A]

Subexhaust Valve Covers [B]

Gaskets [C]

Springs [D]

KX250R6F ∼:

•

Remove:

Subexhaust Valve Cover B olts [A]

Subexhaust Valve Cover [B]

O-rings [C]

Springs [D]

•

Remove:

Retaining Plate Bolts [A]

Retaining Plate [B]

Stopper Pin Allen Bolt [C]

Stopper Pin [D]

Main Lever Allen Bolt [E]

Sublever Allen Bolts [F]

ENGINE TOP END 5-13

Exhaust Valve (KIPS)

•

Pull out the exhaust valve shaft [A] from the cylinder.

•

Remove:

Sublever (Right) [B]

Collar [C]

Main Lever [D] with Spring

Sublever (Left) [E]

•

Pull out:

Main Exhaust Valves [A]

Subexhaust Valves [B]

Exhaust Valve Installation

•

Remove any carbon and clean the valves with a high-flash

point solvent.

•

Check the following for signs of damage.

Exhaust Valves

Exhaust Valve Shaft

Oil Seal on Exhaust Valve Shaft

If necessary, replace damaged or worn items with new

ones

•

Set up the main exhaust valve assembly as shown.

Slide Valve [A]

Valve Holder [B]

•

Check the slide valve move smoothly.

•

Replace the O-ring [A] w ith a new one and apply high

temperature grease to it.

•

Apply a 2-stroke engine oil to the surface [B] of the cylin-

der, shown with X marks.

•

Install the main exhaust valve so that its chamfer side [C]

faces downward.

[D] Front

5-14 ENGINE TOP END

Exhaust Valve (KIPS)

•

Be sure the dowel pins [A] are in positions.

•

Install the retaining plate [B] so that its hollows [C] are

aligned with the dowel pins.

•

Tighten the retaining plate bolts.

Torque - Retaining Plate Bolts: 5.9 N·m (0.60 kgf·m, 52

in·lb)

•

Set the subexhaust valves and sublevers.

○

Apply a 2-stroke engine oil to the surfaces of the cylinder,

shown with X marks (shown in illustration below).

○

Insert the subexhaust valves [A] so that their arrows [B]

point opposite.

[C] Front

○

Sublever (right) [A] does not have the plated (yellow color)

rivet portion [B].

○

Set the sublever (right), aligning its hook portion [C] with

the pin [D] of the subexhaust valve.

[E] Apply a 2-stroke engine oil.

[F] Front

○

Sublever (left) [A] has the plated (yellow color) rivet por-

tion [B]

○

Set the sublever (left), aligning its hook portion [C] with

the pin [D] of the subexhaust valve.

[E] Apply a 2-stroke engine oil.

[F] Front

KX250-R1:

•

Install the subexhaust valve covers on the cylinder.

○

Set the gasket [A] on the valve cover [B] as shown.

ENGINE TOP END 5-15

Exhaust Valve (KIPS)

○

Insert the springs [A] and valve cover with gasket.

○

Tighten the subexhaust valve cover bolts [B].

Torque - Subexhaust Valve Cover Bolts: 8.8 N·m (0.90

kgf·m, 78 in·lb)

NOTE

○

Be careful not to bite the gasket [C] when installing the

subexhaust cover bolts.

KX250R6F ∼:

•

Install the subexhaust valve cover [A] in the cylinder.

○

Replace the O-ring [B] w ith a new one and apply high

temperature grease to it.

○

Insert the springs [A] and valve cover with O-ring.

○

Tighten the subexhaust valve cover bolts [B].

Torque - Subexhaust Cover Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

•

Fit the spring [A] to the main lever [B].

5-16 ENGINE TOP END

Exhaust Valve (KIPS)

•

Apply a high temperature grease to the oil seal lip [A].

•

Apply a 2-stroke engine oil to the surfaces [B] of the ex-

haust valve shaft [C], shown with X marks.

•

Install:

Exhaust Valve Shaft [C]

Sublever (Right) [D]

Collar [E]

Main Lever [F]

Collar [E]

Sublever (Left) [G]

•

Insert the stopper pin [H]. Apply a non-permanent locking

agent to the stopper pin Allen bolt [I] and torque it.

Torque - Stopper Pin Allen Bolt: 3.9 N·m (0.40 kgf·m, 35

in·lb)

•

Apply a non-permanent locking agent to the main lever

Allen bolt [J] and torque it.

Torque - Main Lever Allen Bolt: 3.9 N·m (0.40 kgf·m, 35

in·lb)

•

Apply a non-permanent locking agent to the sublever

Allen bolts [K] and temporarily tighten them.

•

Torque the sublever Allen bolts [A] with the exhaust valve

shaft [B] fully turned clockwise [ C].

Torque - Sublever Allen B olts: 3.9 N·m (0.40 kgf·m, 35 in·lb)

NOTE

○

When exhaust valve shaft turns clockwise and with the

subexhaust valves fully opened, check the end of the

subexhaust valves [A] and exhaust ports [B] are aligned

with. Turn the cylinder upside down and the alignment

of the valve and port can be viewed from the exhaust

pipe port [C].

○

Check that exhaust valves operate smoothly by turning

the exhaust valve shaft.

•

Install the main exhaust valve cover [A].

○

Replace the gasket [B] with a new one.

○

Torque:

Torque - Main Exhaust Valve Cover Bolts [C]: 5.9 N·m (0.60

kgf·m, 52 in·lb)

○

Align the mark [D] on the cover with the hole [E] on the

clamp.

ENGINE TOP END 5-17

Exhaust Valve (KIPS)

•

Install the cylinder (see Cylinder Installation)

Torque - Cylinder Nuts: 33 N·m (3.4 kgf·m, 25 ft·lb)

•

Set the spring [A] as shown.

[B] Governor Shaft Lever

[C] Exhaust Valve Shaft

•

Using a 14 mm open-end wrench [D], install the governor

shaft lever [B] as shown.

•

Tighten:

Torque - G overnor Shaft Lever Mounting Bolt [E]: 5.9 N·m

(0.60 kgf·m, 52 in·lb)

NOTE

○

Put a screw driver ( 6 mm) [F] on the hollow of cylin-

der as shown to prevent the lever link portion [G] from

bending.

•

Install the KIPS cover.

•

Install the removed parts.

5-18 ENGINE TOP END

Muffler (Expansion Chamber, Muffler Body)

Muffler Removal

•

Remove:

Right Radiator Shroud

Right Side Cover

Springs [A] on Connecting Seal

•

Remove the m ounting bolts [A] and pull the muffler body

[B] off toward the rear.

•

Remove the exhaust pipe holding springs [A].

•

Remove the muffler damper mounting bolts [A], and pull

off the expansion chamber to the front ward.

•

Remove the O-rings from the expansion chamber.

○

Be sure to remove exhaust gasket.

Muffler Installation

•

Scrape any carbon out of the exhaust chamber.

•

Check the exhaust O-rings [A] and gasket [B] for signs of

damage.

If necessary, replace them with new ones.

ENGINE TOP END 5-19

Muffler (Expansion Chamber, Muffler Body)

•

Hook [A] the spring side which turns freely to the expan-

sion chamber.

•

Tighten:

Torque - Muffler Damper Mounting Bolts: 8.8 N·m (0.90

kgf·m, 78 in·lb)

•

Install the springs [A] on connecting seal [B], as shown.

[C] Expansion Chamber

[D] Muffler Body

NOTE

○

Apply grease to the indicated area [E] to make service

easy.

•

Tighten:

Torque - Muffler Mounting Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

Muffler Baffle Change

•

Refer to the Exhaust System in the Periodic Maintenance

chapter.

ENGINE RIGHT SIDE 6-1

Engine Right Side

Table of Contents

Exploded View........................................................................................................................ 6-2

Specifications ......................................................................................................................... 6-6

Special Tools .......................................................................................................................... 6-7

Clutch Cable ........................................................................................................................... 6-8

Clutch Lever Free Play Check .......................................................................................... 6-8

Free Play Adjustment ........................................................................................................ 6-8

Clutch Cable Removal ...................................................................................................... 6-8

Clutch Cable Installation ................................................................................................... 6-8

Clutch Cable Lubrication and Inspection .......................................................................... 6-8

Clutch Cover........................................................................................................................... 6-9

Clutch Cover Removal ...................................................................................................... 6-9

Clutch Cover Installation ................................................................................................... 6-9

Right Engine Cover ................................................................................................................6-10

Right Engine Cover Removal............................................................................................ 6-10

Right Engine Cover Installation......................................................................................... 6-10

Right Engine Cover Disassembly ..................................................................................... 6-11

Exhaust Advancer Assembly Disassembly/Assembly ...................................................... 6-12

Right Engine Cover Assembly .......................................................................................... 6-12

Clutch ..................................................................................................................................... 6-13

Clutch Removal................................................................................................................. 6-13

Clutch Installation..............................................................................................................6-14

Friction and Steel Plates Wear, Damage Inspection......................................................... 6-15

Friction and Steel Plate Warp Inspection.......................................................................... 6-15

Spring Free Length Measurement .................................................................................... 6-15

Friction Plate/Clutch Housing Clearance Inspection......................................................... 6-15

Clutch Hub Spline Inspection............................................................................................ 6-16

Release Shaft Removal .................................................................................................... 6-16

External Shift Mechanism....................................................................................................... 6-17

External Shift Mechanism Removal .................................................................................. 6-17

External Shift Mechanism Installation ............................................................................... 6-17

External Shift Mechanism Inspection................................................................................ 6-18

Primary Gear .......................................................................................................................... 6-19

Primary Gear Removal (KX250-R1) ................................................................................. 6-19

Primary Gear Removal (KX250R6F ∼) ............................................................................. 6-19

Primary Gear Installation (KX250-R1) .............................................................................. 6-19

Primary Gear Installation (KX250R6F ∼) .......................................................................... 6-19

Kickstarter............................................................................................................................... 6-21

Kick Pedal Removal.......................................................................................................... 6-21

Kick Pedal Installation....................................................................................................... 6-21

Kickshaft Removal ............................................................................................................ 6-21

Kickshaft Installation ......................................................................................................... 6-21

Kickstarter Assembly Disassembly/Assembly .................................................................. 6-22

Idle Gear Removal ............................................................................................................ 6-22

Idle Gear Installation ......................................................................................................... 6-22

6-2 ENGINE RIGHT SIDE

Exploded View

ENGINE RIGHT SIDE 6-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Clutch Cover Bolts 8.8 0.90 78 in·lb

2 Right Engine Cover Bolts 8.8 0.90 78 in·lb

3 Governor Shaft Lever Positioning Plug 1.0 0.1 10 in·lb

Governor Shaft Lever Mounting Bolt

5.9 0.60 52 in·lb

5 Advancer Lever Mounting A llen Bolt 3.9 0.4 35 in·lb L

6 Primary Gear Nut 78 8.0 58 Lh

Clutch Hub Nut

98 10.0 72

8 Clutch Spring Bolts 8.8 0.90 78 in·lb

9. Clutch Lever

10. Clutch Cable

11. Clutch Cover

12. Right Engine Cover

13. Governor Shaft Lever

14. Exhaust Advancer Assembly

15. Water Pump Drive Gear

16. Primary Gear

17. Clutch Hub

18. Steel Plate

19. Friction Plate

20. Push Rod Holder

21. Clutch Pressure Plate

22. Clutch Housing

23. Sleeve

24. Push Rod

25. Release Lever Shaft

EO: Apply engine oil.

G: Apply grease.

HG: Apply high temperature grease.

L: Apply a nonpermanent locking agent to the threads.

Lh: Left-hand threads

M: Apply m olybdenum disulfide grease.

O: Apply oil.

R: Replacement Part

A: KX250-R1 Model

B: KX250T6F Model ∼

6-4 ENGINE RIGHT SIDE

Exploded View

ENGINE RIGHT SIDE 6-5

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Gear Set Lever Nut 8.8 0.90 78 in·lb

2 Ratchet Plate Mounting Bolts 8.8 0.90 78 in·lb

3 Shift Mechanism Return Spring Pin 42 4.3 31 L

4 Shift Pedal Bolt 8.8 0.90 78 in·lb

5 Ratchet Guide Bolt 8.8 0.90 78 in·lb

6 Kick Pedal Mounting Bolt 25 2.5 18

7. Shift Shaft

8. Shift Pedal

9. Ratchet Assembly

10. Gear Set Lever

11. Shift Drum Operating Cam

12. Ratchet Gear

13. Kick Gear

14. Kick Shaft

15. Kickstarter Idle Gear

16. Kick Pedal

G: Apply grease.

L: Apply a nonpermanent locking agent to the threads.

M: Apply m olybdenum disulfide grease.

R: Replacement Part

St: Stake the fasteners.

6-6 ENGINE RIGHT SIDE

Specifications

Item Standard Service Limit

Clutch

Lever Free Play 8 ∼ 13 mm (0.3 ∼ 0.5 in.) –––

Friction Plate Thickness 2.92 ∼ 3.08 mm (0.115 ∼ 0.121 in.) 2.8 mm (0.110 in.)

Steel Plate Thickness 1.46 ∼ 1.74 mm (0.057 ∼ 0.069 in.) 1.36 mm (0.054 in.)

Friction Plate Warp

0.15 mm (0.006 in.) or less 0.3 mm (0.119 in.)

Steel Plate Warp 0.2 mm ( 0.008 in.) or less 0.3 mm (0.119 in.)

Clutch Spring Free Length 35.0 mm (1.378 in.) 33.6 mm (1.323 in.)

Friction Plate/Clutch Housing

Clearance

0.15 ∼ 0.45 mm (0.0059 ∼ 0.0177 in.) 0.8 mm (0.0315 in.)

ENGINE RIGHT SIDE 6-7

Special Tools

Outside Circlip Pliers:

57001-144

Clutch Holder:

57001-1243

Flywheel Holder:

57001-1313

Gear Holder, m2.0:

57001-1557

6-8 ENGINE RIGHT SIDE

Clutch Cable

Due to friction plate wear and clutch cable stretch over

a long period of use, the clutch must be adjusted in accor-

dance with the Periodic Maintenance Chart.

WARNING

To avoid a serious burn, never touch the hot engine

or exhaust chamber during clutch adjustment.

Clutch Lever Free Play Check

•

Refer to the Clutch Lever Free Play Check in the Periodic

Maintenance chapter.

Free Play Adjustment

•

Refer to the Clutch Lever Free Play Adjustment in the

Periodic Maintenance chapter.

Clutch Cable Removal

•

Loosen the locknut [A] at the middle of clutch cable, and

turn the adjusting nut [B] to give the cable plenty of play.

•

Slide the dust cover out of place.

•

Turn the adjuster [A] to give the cable plenty of play.

•

Line up the slot [B] in the clutch lever, adjuster and ad-

justing bolt, and free the cable from the clutch lever.

•

Remove the magneto cover.

•

Free the clutch inner cable tip [A] from the clutch release

lever [B].

CAUTION

Do not remove the clutch release shaft unless it is

absolutely necessary. If removed, release shaft oil

seal must be replaced with a new one.

•

Pull the clutch cable out of frame.

Clutch Cable I nstallation

•

Run the clutch cable according to the Cable, Wire and

Hose Routing in the Appendix chapter.

•

Adjusttheclutchcable(seeFreePlayAdjustment).

Clutch Cable Lubrication and Inspection

•

Refer to the General Lubrication in the Periodic Mainte-

nance chapter.

ENGINE RIGHT SIDE 6-9

Clutch Cover

Clutch Cover Removal

•

Drain the engine oil (see Engine Bottom End/Transmis-

sion chapter).

•

Remove the brake pedal (see Brake chapter).

•

Unbolt the clutch cover bolts [A], and take off the clutch

cover [B].

Clutch Cover I nstallation

•

There are two knock pins of the mating surfaces of right

engine cover and clutch cover.

•

Replace the clutch cover gasket with a new one.

•

Tighten the clutch cover bolts.

Torque - Clutch Cover Bolts: 8.8 N·m (0.90 kgf·m, 78 in·lb)

•

Install the brake pedal (see Brake chapter)

6-10 ENGINE RIGHT SIDE

Right Engine Cover

Right Engine Cover Removal

•

Remove:

Engine Oil (drain) (see Engine Bottom End/Transmis-

sion chapter)

Coolant (drain) (see Cooling System chapter)

Cooling Hose Lower End

Kick Pedal

Brake Pedal

Muffler

•

Unscrew the KIPS cover bolt [A] and remove the KIPS

cover [B] from the right side of the c ylinder.

•

Remove:

Bolt [A] and Spring [B]

Governor Shaft Lever [C]

•

Remove the cover bolts [A] and take off the right engine

cover [B] and gasket.

Right Engine Cover Installation

•

There are two knock pins of the mating surfaces of the

crankcase and right engine cover.

•

In case the exhaust advancer assembly has been re-

moved, install it and turn the gear so as to level the gear

drive pin [A].

CAUTION

If the gear drive pin is not positioned level, it may

fall out when installing the right engine cover.

•

Apply a high-temperature grease to the kick pedal oil seal

lips and kick shaft spline.

•

Tighten the right engine cover bolts and kick shaft mount-

ing bolt.

Torque - Right Engine Cover Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

Kick Pedal Mounting Bolt: 25 N·m (2.5 kgf·m, 18

ft·lb)

ENGINE RIGHT SIDE 6-11

Right Engine Cover

•

Set the spring [A] as shown.

[B] Governor Shaft Lever

[C] Exhaust Valve Shaft

•

Using a 14 mm open-end wrench [D], install the governor

shaft lever [B] as shown.

•

Tighten:

Torque - G overnor Shaft Lever Mounting Bolt [E]: 5.9 N·m

(0.60 kgf·m, 52 in·lb)

NOTE

○

Put a screw driver ( 6 mm) [F] on the hollow of cylin-

der as shown to prevent the lever link portion [G] from

bending.

•

Install the KIPS cover.

Torque - KIPS Cover Bolts: 5.9 N ·m (0.60 kgf·m, 52 in·lb)

•

Apply grease to the inside of the brake pedal boss.

•

Tighten the brake pedal mounting bolt.

Torque - Brake Pedal Mounting Bolt: 25 N·m (2.5 kgf·m, 18

in·lb)

•

Fillthecoolingsystemwithcoolant(seeCoolingSystem

chapter).

•

Fill the transmission with oil (see Engine Bottom

End/Transmission chapter).

•

Check the rear brake.

Right E ngine Cover Disassembly

•

Remove the right engine cover.

•

Turn the governor shaft lever [A] to the left, and remove

the exhaust advancer assembly [B].

•

Remove the Allen bolts [C], and take off the advancer

lever.

•

Pull the dust cover [D].

•

Remove the plug screw [A] and take out the governor

shaft lever positioning pin [B].

•

Pull the governor shaft lever [C] out of the right engine

cover.

•

Pull off the water pump s haft (see Cooling System chap-

ter).

6-12 ENGINE RIGHT SIDE

Right Engine Cover

Exhaust Advancer Assembly Disassembly/Assembly

•

The exhaust advancer assembly [A] consists of the fol-

lowing parts.

[A] Pins

[B] Rod

[C] Guide

[D] O-ring

[E] Steel Balls

[F] Holder

[G] Needle Bearing

[H] Spacer

[I] Collar

[J] Spring

[K] Gear

•

Check the exhaust advancer assembly parts for damage.

Any damaged parts should be replaced with new ones.

•

When assembling, apply molybdenum disulfide grease

between the rod and inside/outside diameter parts of the

holder, needle bearing and spacer .

Right Engine Cover Assembly

•

Apply high temperature grease to the oil seal lips before

inserting the governor shaft lever.

•

Apply molybdenum disulfide grease to the surface of the

lever shaft, and insert the governor shaft lever [A] into the

right engine cover hole.

•

Insert the positioning pin [B] into the hole then fit it to the

groove [C] of the shaft.

•

Tighten the governor shaft lever positioning plug screw

[D] securely.

Torque - Governor Shaft Lever Positioning Plug: 1.0 N·m

(0.1 kgf·m, 10 in·lb)

•

Install the dust cover.

•

Apply a non-permanent locking agent to the threads of

the advancer mounting Allen bolts.

•

Tighten the advancer lever mounting Allen bolts [A].

Torque - Advancer Lever Mounting Allen Bolts: 3.9 N·m

(0.4 kgf·m, 35 in·lb)

•

Fit the advancer lever pin [B] into the groove [C] on the

exhaust advancer assembly [D], and install the assembly

in the engine cover while turning the governor shaft lever

to the left.

ENGINE RIGHT SIDE 6-13

Clutch

Clutch Removal

•

Remove the clutch c over (see Clutch Cover Removal).

•

Remove the c lutch spring bolts [A], spring, and clutch

pressure plate [B].

•

Remove the push rod holder assy [A], friction plates [B],

steel plates [C], and push rod.

•

Remove the clutch hub nut [A] and washer.

NOTE

○

Use the clutch holder [B] to prevent the clutch hub from

rotating.

Special Tool - Clutch Holder: 57001-1243

•

Remove the clutch hub and housing, needle bearing [A],

and sleeve [B].

6-14 ENGINE RIGHT SIDE

Clutch

Clutch Installation

•

Apply molybdenum disulfide grease to the outside of the

sleeve.

•

Apply transmission oil to the inside of the clutch housing

gear and kickstarter driven gear.

•

Install the sleeve, needle bearing, clutch hub and hous-

ing.

○

Do not forget to install the thrust washer [A] before in-

stalling the clutch hub [B].

•

Tighten the c lutch hub nut [A].

Torque - Clutch H ub Nut: 98 N·m (10 kgf·m, 72 ft·lb)

NOTE

○

Use the clutch holder [B] to prevent the clutch hub from

rotating.

Special Tool - Clutch Holder: 57001-1243

•

Install the friction plates and steel plates, starting with a

friction plate and alternating them. Finishing with a friction

plate.

CAUTION

If dry steel plates and friction plates are installed,

apply transmission oil to the surfaces of each plate

to avoid clutch plate seizure.

•

Apply molybdenum disulfide grease to the rubbing portion

of the push rod holder.

•

Tighten the clutch spring bolts fixing the flywheel with the

Special Tool.

Torque - Clutch Spring Bolts: 8.8 N·m (0.90 kgf·m, 78 in·lb)

Special Tool - Flywheel Holder: 57001-1313

ENGINE RIGHT SIDE 6-15

Clutch

•

Check the release shaft lever positions [A].

○

Remove the magneto cover.

○

Pushing [B] the release shaft lever [C] lightly upward,

measure the distance between the lever and the seating

surface [D] of clutch cable, as shown.

Release Shaft Lever Position

Standard:

33.5 ∼ 40.5 mm

If the lever position is not within the standard, select the

correct thickness o f adjusting washer(s) according to the

tables shown.

Adjusting Washers

Thickness Part Number

1.5 mm 92200-1548

1.0 mm 92200-0045

Release Shaft Lever Position and Adjusting Washer

Selection

Position Distan ce Judgment

Washers

Thickness

Qty

33.5 mm to 40.5 mm

Standard

1.5 mm 1

More than 40.5 mm Too bi g 1.0 mm 1

Less than 33.5 mm Too sm al l 1.0 mm 2

Remove the push rod holder assy as necessary and re-

install the clutch.

Friction and Steel Plates Wear, Damage Inspection

•

Refer to the Friction and Steel Plates Wear, Damage In-

spection in the Periodic Maintenance chapter.

Friction and Steel Plate Warp Inspection

•

Refer to the Friction and Steel Plate Wrap Inspection in

the Periodic Maintenance chapter.

Spring Free Length Meas urement

•

Since the spring [A] becomes shorter as it weakens,

check its free length to determine its condition.

If any of the springs is shorter than the service limit, it must

be replaced.

Standard: 35 mm (1.378 in.)

Service Limit: 33.6 mm (1.323 in.)

Friction Plate/Clutch Housing Clearance Inspection

•

Measure the clearance between the tangs [A] on the fric-

tion plate and the fingers [B] of the clutch housing.

If this clearance is excessive, the clutch will be noisy.

If the clearance exceeds the service limit, replace the fric-

tion plates.

Friction Plate/Clutch Housing Clearance

Standard: 0.15 ∼ 0.45 mm (0.0059 ∼ 0.0177 in.)

Service Limit: 0.8 mm (0.0315 in.)

6-16 ENGINE RIGHT SIDE

Clutch

Clutch Hub Spline Inspection

•

Visually inspect where the teeth on the steel plates wear

against the splines [A] of the clutch hub.

If there are notches worn into the splines, replace the

clutch hub. Also, replace the clutch plates if their teeth

are damaged.

Release Shaft Removal

•

When the release shaft remove, do following procedure.

○

Remove the magnet cover and the magneto flywheel.

○

Remove the clutch cover and loosen the clutch spring

bolts.

○

Disconnect the clutch cable lower end [A] and then re-

move the release shaft assembly [B].

ENGINE RIGHT SIDE 6-17

External Shift Mechanism

External Shift Mechanism Removal

•

Remove:

Shift Pedal

Right Engine Cover (see Right Engine Cover Removal)

Clutch Housing (see Clutch Removal)

•

Pull out the external shift shaft [A].

•

Remove the bolts [B] and take off the shift ratchet assem-

bly [C] with collar.

•

Remove the nut [D], and take off the gear set lever [E].

External Shift Mechanism Installation

•

Install the gear set lever.

○

Do not forget to install the color.

•

Tighten the gear set lever nut.

Torque - Gear Set Lever Nut: 8.8 N·m (0.9 0 k gf·m, 78 in·lb )

•

Set up the shift ratchet assembly as shown in the figure.

Ratchet [A]

Pawls [B]

Pins [C]

Springs [D]

•

Then install the ratchet assembly [A] to the ratchet plate

[B] as shown in the figure.

•

Install the ratchet assembly to the shift drum.

•

Tighten:

Torque - Ratchet Plate Mounting Bolts: 8.8 N·m (0.90 kgf·m,

78 in·lb)

○

Do not forget to install the collar [A].

•

Before installing the shift shaft, apply high temperature

grease to the oil seal lips and shift shaft splines.

•

Instal the removal parts.

6-18 ENGINE RIGHT SIDE

External Shift Mechanism

•

Install the shift pedal [A] as shown.

[B] 4 ∼ 24 mm (0.16 ∼ 0.94 in.)

•

Tighten:

Torque - Shift Pedal Bolt: 8.8 N ·m (0.90 kgf·m, 78 in·lb)

External Shift Mechanism Inspection

•

Check the shift shaft [A] for bending or damage to the

splines.

If the shaft is bent, straighten or replace it. If the splines

are damaged, replace the shift mechanism.

•

Check the return spring [B] for cracks or distortion.

If the spring i s damaged in any way, replace it.

•

Check the shift mechanism arm [C] for distortion.

If the shift mechanism arm is damaged in any way, re-

place the shift mechanism.

•

Check the collar [D] for damage.

If the collar is damaged in any way, replace it.

•

Check the ratchet assembly for damage.

If ratchet, pawls, pins or springs are damaged in any way,

replace them.

•

Check that the return spring pin [A] is not loose.

If it is loose, unscrew it, apply a non-permanent locking

agent to the threads, and tighten it.

Torque - Shift Mechnism Return Spring Pin: 42 N·m (4.3

kgf·m, 31 ft·lb)

•

Check the gear set lever and its spring for cracks or dis-

tortion.

If the lever or spring is damaged in any way, replace them.

•

Visually inspect the shift drum cam.

If it is badly worn or if it s hows any damage, replace it.

ENGINE RIGHT SIDE 6-19

Primary Gear

Primary Gear Removal (KX2 50-R1)

•

Remove the right engine cover (see Right Engine Cover

Removal)

•

Removetheclutch(seeClutchRemoval).

•

Remove the circlip [A], and take off the water pump drive

gear [B] and primary gear [C].

Special Tool - Outside Circlip Pliers: 57001-144

Primary Gear Removal (KX250R6F

∼

)

•

Remove:

Right Engine Cover (see Right Engine Cover Removal)

•

Removetheclutch(seeClutchRemoval).

•

Temporarily install the clutch housing [A].

•

Using the gear holder [B], secure the primary gear.

Special Tool - Gear Holder, m2.0: 57001-1557

•

Remove the clutch housing.

•

Remove the primary gear nut [C], washer, water pump

drive gear [D] and the primary gear [E].

○

Primary gear nut is left-hand threads.

Primary Gear Installation (KX250-R1)

•

Install the following as shown.

Primary Gear [A]

Water Pump Drive Gear [B]

•

Replace the old circlip with a new one [C].

Special Tool - Outside Circlip Pliers: 57001-144

Primary Gear Installation (KX250R6F

∼

)

•

Fit the woodruff key [A] securely in the slot of the crank-

shaft before installing the primary gear.

6-20 ENGINE RIGHT SIDE

Primary Gear

•

Insert the primary gear [A] and water pump drive gear [B]

to the crankshaft.

•

Install the washer [C] so that concave side faces inward

(primary gear side).

•

Install the primary gear nut [D].

•

Using the gear holder [A], secure the clutch gear and the

bottom of the primary gear; then, tighten the primary gear

nut [B].

○

Primary gear nut is left-hand threads.

Torque - Primary Gear Nut: 78 N·m (8.0 kgf·m, 58 ft·lb)

Special Tool - Gear Holder, m2.0: 57001-1557

•

Install:

Clutch (see Clutch Installation)

Right Engine Cover (see Right Engine Cover Installa-

tion)

ENGINE RIGHT SIDE 6-21

Kickstarter

Kick Pedal Removal

•

Remove:

Mounting Bolt [A]

Kick Pedal [B]

Kick Pedal Installation

•

Install the kick pedal [A] as shown.

[B] 8 ∼ 28 mm (0.32 ∼ 1.10 in.)

•

Apply a non-permanent locking agent to the mounting

bolt.

•

Torque.

Torque - Kick Pedal Bolt: 25 N·m (2.5 kgf·m, 18 ft·lb)

Kickshaft Removal

•

Remove:

Right Engine Cover (see Right Engine Cover Removal)

Clutch Housing (see Clutch Removal)

•

Pull the end of the kick spring [A] out of the hole in the

crankcase.

•

Turn the kickshaft counterclockwise [C] and remove the

kickstarter assembly [B].

•

Remove the bolts [A], take off the ratchet guide [B].

Kickshaft Installation

•

Install the ratchet guide [A].

Torque - Ratchet Guide Bolt: 8.8 N·m (0.90 kgf·m, 78 in·lb)

•

Apply molybdenum disulfide grease to the end of the kick-

shaft.

•

Insert the kickstarter assembly [B] into the crankcase.

○

Securely engage the s topper portion [C] of the ratchet

gear with the guide.

•

Insert the spring end [D] into the hole [E].

•

Install:

Clutch Housing (see Clutch Installation)

Right Engine Cover (see Right Engine Cover Installa-

tion)

6-22 ENGINE RIGHT SIDE

Kickstarter

Kickstarter Assembly Disassembly/Assembly

•

The kickstarter assembly consists of the following parts.

•

Check the kickstarter assembly parts for damage. Any

damaged parts should be replaced with new ones.

[A] Idle Gear

[B] Circlip

[C] Washer

[D] Spring

[E] Ratchet Gear

[F] Kick Gear

[G] Kick Shaft

[H] Kick Spring

[I] Spring Guide

•

Apply molybdenum disulfide grease to the inside of the

kick gear and ratchet gear.

•

When assembling the ratchet gear [A] onto the kick shaft

[B], align the punch mark [C] on the ratchet gear with the

punch mark [C] on the k ick shaft.

•

Replace the circlips that were removed with new ones.

Special Tool - Out side Circ lip Pliers : 57001-144

Idle Gear Removal

•

Remove:

Right Engine Cover (see Right Engine Cover Removal)

Clutch Housing (see Clutch Removal)

•

Remove the circlip [A] and pull off the idle gear [B].

Special Tool - Out side Circ lip Pliers : 57001-144

Idle Gear Installation

•

Apply molybdenum disulfide grease to the inside of the

idle gear.

•

Replace the circlip with a new one.

Special Tool - Out side Circ lip Pliers : 57001-144

ENGINE REMOVAL/INSTALLATION 7-1

Engine Removal/Installation

Table of Contents

Exploded View........................................................................................................................ 7-2

Special Tool ............................................................................................................................ 7-4

Engine Removal/Installation ................................................................................................... 7-5

Engine Removal................................................................................................................ 7-5

Engine Installation............................................................................................................. 7-6

7-2 ENGINE REMOVAL/INSTALLATION

Exploded View

ENGINE REM OVAL/INSTALLATION 7-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Engine Mounting Nuts 49 5.0 36

Engine Mounting Bracket Nuts (Engine Side 10

mm)

49 5.0 36

Engine Mounting Bracket Nuts (Frame Side 8 mm)

29 3.0 22

4 Swing Arm Pivot Shaft Nut 98 10.0 72

5. Frame

6. Engine Mounting Bracket

7. Swing Arm Pivot Shaft

7-4 ENGINE REMOVAL/INSTALLATION

Special Tool

Jack:

57001-1238

ENGINE REM OVAL/INSTALLATION 7-5

Engine Removal/Installation

Engine Removal

•

Drain the engnie oil (see Engine Bottom End/Transmis-

sion chapter).

•

Drain the coolant (see Cooling System chapter).

•

Remove:

Radiator Shrouds

Side Covers

Seat

Fuel Tank

Cooling Hoses

Radiators

Expansion Chamber

Ignition Coil

Spark Plug Cap

Carburetor (with C ables, Hoses and Wires)

Clutch Cable Lower End

Drive Chain

Engine Sprocket

Shift Pedal

Brake P edal

•

Disconnect the magneto output lead, and free the leads

from the clamp at the left side of the cylinder.

•

Unbolt the mounting bolts [A] and remove the engine

mounting brackets [B].

•

Place a jack [A] under the frame to lift the motorcycle off

the ground, and put blocks under the front and rear tires

to steady the motorcycle.

WARNING

The swingarm pivot shaft also serves as the en-

gine mounting bolt. Take precautions to insure the

frame is well supported, and that the motorcycle

will not fall over when the pivot shaft is removed.

Special Tool - Jack: 57001-1238

•

Remove the engine mounting bolts [B].

•

Pull out the swing arm pivot shaft [C].

•

Lift the engine out to the right.

7-6 ENGINE REMOVAL/INSTALLATION

Engine Removal/Installation

Engine Installation

•

Tighten the following nuts.

Torque - Engine Mounting Nuts:

49N·m(5.0kgf·m,36ft·lb)

Engine Mounting Bracket Nuts:

10 m m: 49 N· m (5.0 kgf·m, 36 ft· lb )

8 mm: 29 N·m (3.0 kgf·m, 22 ft·lb)

Swing Arm Pivot Shaft Nut: 98 N·m (10.0 kgf·m, 72

ft·lb)

•

To route the leads, cables and hoses, refer to the Appen-

dix chapter.

•

To install parts removed, refer to the appropriate chapters.

•

Fill the cooling system with coolant (see Cooling System

chapter).

•

Fill the engine with engine oil (see Engine Bottom

End/Transmission chapter).

•

Adjust:

Throttle Cable

Clutch Cable

Drive Chain

Rear Brake

ENGINE BOTTOM END/TRANSMISSION 8-1

Engine Bottom End/Transmission

Table of Contents

Exploded View........................................................................................................................ 8-2

Specifications ......................................................................................................................... 8-4

Special Tools .......................................................................................................................... 8-5

Transmission Oil..................................................................................................................... 8-6

Oil Level Inspection........................................................................................................... 8-6

Oil Change ........................................................................................................................ 8-6

Crankcase .............................................................................................................................. 8-7

Crankcase Splitting ........................................................................................................... 8-7

Crankcase Disassembly ................................................................................................... 8-8

Crankcase Assembly ........................................................................................................ 8-8

Crankshaft, Connecting Rod .................................................................................................. 8-12

Crankshaft Removal ......................................................................................................... 8-12

Crankshaft Installation ...................................................................................................... 8-12

Crankshaft Disassembly ................................................................................................... 8-12

Crankshaft Assembly ........................................................................................................ 8-12

Connecting Rod Big End Radial Clearance ...................................................................... 8-13

Connecting Rod Big End Seizure ..................................................................................... 8-13

Connecting Rod Big End Side Clearance ......................................................................... 8-13

Crankshaft Runout ............................................................................................................ 8-13

Crankshaft Alignment........................................................................................................ 8-14

Transmission .......................................................................................................................... 8-15

Shaft Removal .................................................................................................................. 8-15

Shaft Installation ...............................................................................................................8-15

Shaft Disassembly ............................................................................................................ 8-15

Shaft Assembly ................................................................................................................. 8-15

Shift Drum and Fork Installation ........................................................................................ 8-16

Shift Fork Bending ............................................................................................................ 8-17

Shift Fork/Gear Groove Wear ........................................................................................... 8-17

Shift Fork Guide Pin/Shift Drum Groove Wear ................................................................. 8-17

Gear Damage ................................................................................................................... 8-17

Gear Dog/Gear Dog Hole Damage................................................................................... 8-18

Ball Bearing Wear ............................................................................................................. 8-18

8-2 ENGINE BOTTOM END/TRANSMISSION

Exploded View

ENGINE BOTTOM END/TRANSMISSION 8-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Crankcase Bolts 8.8 0.90 78 in·lb

2 Bearing Retaining Screws 4.9 0.50 43 in·lb L

3 Shift Drum B earing Retaining Bolts 8.8 0.90 78 in·lb

Transmission Oil Drain Plug

20 2.0 14.5

5 Drive Shaft Bearing Retaining Bolts 8.8 0.90 78 in·lb

6 Flywheel Nut 78 8.0 58

Shift Drum Operating Cam Bolt

24 2.4 17 L

8. Left Crankcase

9. Right Crankcase

10. Crankshaft Assembly

11. Stator

12. Flywheel Magneto

13. Drive Shaft

14. Output Shaft

15. Engine Sprocket

16. Shift Fork

17. Shift Rod

18. Shift Drum Operating Cam

19. Shift Drum

20. Shift Pedal

21. Shift Shaft

EO: Apply engine oil to the transmission gears and shift forks, etc.

G: Apply high temperature grease.

L: Apply a non-permanent locking agent.

LG: Apply liquid gasket to the left and right case mating surface.

M: Apply m olybdenum disulfide grease.

O: Apply 2-stroke engine oil.

R: Replacement parts.

8-4 ENGINE BOTTOM END/TRANSMISSION

Specifications

Item Standard Service Limit

Transmission Oil

Grade API SE, SF or SG –––

API SH, SJ or SL with JASO MA

Viscosity SAE 10W-40 –––

Capacity 0.85 L (0.90 US qt)

–––

Crankshaft, Connecting Rod

Connecting Rod Bend Not more than 0.03 mm (0.0012 in.)/100

mm (3.937 in.)

0.2 mm (0.008 in.)/100

mm (3.937 in.)

Connecting Rod Big End

Radial Clearance

0.037 ∼ 0.049 mm (0.0015 ∼ 0.0019 in.) 0.10 mm (0.004 in.)

Connecting Rod Big End Side

Clearance

0.45 ∼ 0.55 mm (0.0177 ∼ 0.0217 in.) 0.70 mm (0.028 in.)

Crankshaft Runout TIR 0.03 mm (0.0012 in.) or less TIR 0.05 mm (0.002 in.)

Transmission

Gear Backlash 0.02 ∼ 0.20 mm (0.0008 ∼ 0.0078 in.) 0.30 mm (0.012 in.)

Shift Fork Ear Thickness 4.40 ∼ 4.50 mm (0.1732 ∼ 0.1772 in.) 4.30 mm (0.169 in.)

Gear Shift Fork G roove W idth 4.55 ∼ 4.65 mm (0.1791 ∼ 0.1830 in.) 4.75 mm (0.187 in.)

Shift Fork Guide Pin Diameter 5.90 ∼ 6.00 mm (0.2323 ∼ 0.2362 in.) 5.80 mm (0.228 in.)

Shift Drum Groove Width 6.05 ∼ 6.20 mm (0.2382 ∼ 0.2440 in.) 6.25 mm (0.246 in.)

ENGINE BOTTOM END/TRANSMISSION 8-5

Special Tools

Bearing Puller Adapter:

57001-136

Outside Circlip Pliers:

57001-144

Bearing Puller:

57001-158

Crankcase Splitting Tool Assembly:

57001-1098

Bearing Driver Set:

57001-1129

Crankshaft Jig:

57001-1174

Kawasaki Bond (Liquid Gasket - Silver):

92104-002

8-6 ENGINE BOTTOM END/TRANSMISSION

Transmissio n Oil

In order for the transmission and clutch to function prop-

erly, always maintain the transmission oil at the proper level

and change the oil periodically.

WARNING

Motorcycle operation with insufficient, deteri-

orated, or contaminated transmission oil will

accelerated wear and may result in transmission

seizure, and injury.

Oil Level Inspection

•

Refer to the Transmission Oil Level Inspection in the Pe-

riodic Maintenance chapter.

Oil Change

•

Refer to the Transmission Oil C hange in the Periodic

Maintenance chapter.

ENGINE BOTTOM END/TRANSMISSION 8-7

Crankcase

Crankcase Splitting

•

Remove the engine (see the Engine Removal/Installation

chapter).

•

Set the engine on a clean surface while parts are being

removed.

•

Remove:

Cylinder Head (see Engine Top End chapter)

Cylinder (see Engine Top End chapter)

Piston (see Engine Top End chapter)

Right Engine Cover (see Engine Right Side chapter)

Clutch (see Engine Right Side chapter)

Primary Gear (see Engine Right Side chapter)

Kickstarter Assembly (see Engine Right Side chapter)

Kickstarter Idle Gear (see Engine Right Side chapter)

External Shift Mechanism (see Engine Right Side chap-

ter)

Shift Ratchet Assembly (see Engine Right Side chapter)

Gear Set Lever [A]

Shift Drum Operating Cam [B]

Output Shaft Sleeve [C] and O-rings [D]

Flywheel Magneto and Stator (see Electrical System

chapter)

•

Remove the crankcase bolts [A].

•

Install the crankcase splitting tool [A] and bearing puller

adapter [B] into the left side of the crankcase. Be certain

to screw the tool in all the way.

Special Tools - Bearing Puller Adapter: 57001-136

Crankcase Splitting Tool Assembly: 57001

-1098

•

Tighten the bolt on the crankcase splitting tool to split t he

crankcase halves.

•

Once the crankcase is split, remove the crankcase split-

ting tool, and lift off the left crankcase half.

8-8 ENGINE BOTTOM END/TRANSMISSION

Crankcase

•

Pull out the shift rods [A].

•

Disengage the shift fork guide pins from the shift drum

grooves.

•

Take off the shift drum [B]

•

Remove the shift forks [C] from the transmission gears.

•

Take out the drive shaft [D] and output shaft [E] together

with their gear meshed.

•

Remove the crankshaft from the right crankcase half us-

ingapress.

Crankcase Disassembly

CAUTION

Do not remove the bearings and the oil seals unless

it is necessary.

Removal may damage them.

Crankcase Assembly

•

Before fitting the left case on the right case, note the fol-

lowing:

○

Chip off the old gasket from the mating surfaces of the

crankcase halves, and clean off the crankcase with a high

flash-point solvent. After cleaning, apply transmission oil

to the transmission gears, shift drum, shift forks and so

on.

○

Be sure to replace any oil seal removed with a new one.

Press in the new oil seal using a press and suitable tools

so that the seal surface is flush with the surface of the

crankcase.

○

Apply high temperature grease to the oil seal lips.

○

Press in the ball bearings using the bearing driver set until

the bearing is bottomed.

Special Tool - Bearin g Driver Set: 57001-1129

○

Install the bearings for the output shaft and drive shaft

into the left crankcase half so that stepped sides face [A]

inside.

ENGINE BOTTOM END/TRANSMISSION 8-9

Crankcase

○

Install the bearing for the shift drum so that its s ealed side

faces [ A] inside.

CAUTION

Install the bearings for the crankshaft in the right

and left crankcase so that their sealed sides face

toward the oil seal side.

○

Tighten the output and drive shaft bearing retaining

bolts/screws securely.

Torque - Bearing Retaining Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

Bearing Retaining Screws: 4.9 N·m (0.50 kgf·m, 43

in·lb)

○

If the crankshaft bearings stay on the crankshaft when

splitting the crankcase, remove the bearings from the

crankshaft and reinstall them in the crankcase, and then

assemble the crankcase (see Crankshaft Removal and

Installation).

•

Turn the crankshaft [A] to BDC, and install the crankshaft

jig [C] between the flywheels opposite the connecting rod

[B] big end to protect flywheel alignment as shown.

○

If the crankshaft has been removed from the crankcase,

install the jig between the crankshaft flywheels before

pressing the crankshaft into the right crankcase half.

Special Tool - Crankshaft Jig: 57001-1174

•

Install the transmission shaft as a set (see this chapter).

•

Install the shift fork, shift drum and shift rod.

•

Check to see that the crankcase knock pins [A] and O-ring

[B] are in place on the right crankcase half.

○

Replace the O-ring with a new one.

8-10 ENGINE BOTTOM END/TRANSMISSION

Crankcase

•

Apply liquid gasket to the mating surface [A] of the

crankcase half.

Sealant - Kawasaki Bond (Liquid Gasket - Silver): 92104

-002

○

Apply liquid gasket [B] to the outside of O-ring seating

surface [C].

○

After fitting the left case on the right case, wipe off any

excess liquid gasket, shown w ith X marks.

NOTE

○

Make the application finish within 30 minutes when the

liquid gasket to the mating surface of left c rankcase half

is applied.

•

Using a suitable tool on the left crankcase to press [A]

around the hole for the crankshaft, fit the crankcase

halves together with a press on the tool.

NOTE

○

Constantly check the alignment of the two crankcase

halves, and the position of the transmission shafts, and

shift drum. The front and rear of the crankcase must be

pushed together evenly.

ENGINE BOTTOM END/TRANSMISSION 8-11

Crankcase

•

Remove the crankshaft jig from the flywheels.

•

Tighten the crankcase bolts starting with the ones around

the crankshaft, and then the farther ones.

○

At this time, tighten the crankcase bolt [A] and clamp [B]

for the breather hoses together.

○

At this time, tighten the crankcase bolt [C] and plate [D]

for the exhaust pipe holding spring together.

Torque - Crankcase Bolts: 8.8 N·m (0.90 kgf·m, 78 in·lb)

•

Check to see that the crankshaft, drive shaft, and output

shaft all turn freely (in the neutral position).

If the crankshaft will not turn, probably the crankshaft is

not centered; tap the appropriate end of the crankshaft

with a mallet to reposition it.

•

Install the gear set lever [A].

○

Fit each end of the spring [B] or original positions.

○

Do not forget to install the colar and washer [C].

•

Tighten the gear set lever nut [D].

Torque - Gear Set Lever Nut: 8.8 N·m (0.9 kgf·m, 78 in·lb)

•

To install the shift drum cam [A], use the driver [B] to bring

the gear set lever [C] to the bottom of the crankcase.

•

Mate the shift drum pin [D] into the shift drum hole.

○

Fit the groove [E] of the shift drum cam on the shift drum

pin.

•

Apply non-permanent locking agent to the shift drum cam

bolts and tighten them.

Torque - Shift Drum Operating Cam Bolt: 24 N·m (2.4 kgf·m,

17 ft·lb)

•

Check to see that gears shift smoothly from 1st to 5th

gear, and 5th to 1st while spinning the output shaft.

•

Set the shift drum in the neutral position.

•

Replace the O-rings [A] on the output shaft with new ones.

•

Install two O-rings on the grinding faces of the output shaft

while expanding the O-ring by the hand.

•

Apply grease to t he inside of the output shaft collar [B].

•

Insert the collar with the oil groove end facing [C] in.

•

Install the other removed parts.

8-12 ENGINE BOTTOM END/TRANSMISSION

Crankshaft, Connecting Rod

Crankshaft Removal

•

Split the crankcase (see Crankcase Splitting).

•

Remove the transmission shafts (see Transmission Shaft

Removal).

•

Using a press, remove the crankshaft from the right

crankcase.

○

If the bearings stay on the crankshaft when splitting the

crankcase or removing the crankshaft from the right

crankcase, remove the bearings from the crankshaft with

a bearing puller [A] and adapter [B].

Special Tools - Bearing Puller: 57001-158

Bearing Puller Adapter: 57001-136

Crankshaft Installation

•

When installing the crankshaft bearings [B], apply high

temperature grease to the outer sides of the bearings,

and then press them into the crankcase using the bearing

driver [A] until the bearing bottoms against the step.

○

Position the crankcase half so that the main bearing hous-

ing is seated on a suitable press fixture.

○

Install the crankshaft bearing so that the mark side faces

out.

Special Tool - Bearin g Driver Set: 57001-1129

•

Insert the crankshaft jig [C] between the c rankshaft fly-

wheels opposite the connecting rod [B] big end to protect

flywheel alignment as shown, and press the crankshaft

[A] into the right crankcase.

○

When pressing, position the jig in the crankcase opening

so the jig does not hit the crankcase.

Special Tool - Crankshaft Jig: 57001-1174

•

Apply 2-stroke oil to the connecting rod big end bearing.

Crankshaft Disassembly

Since assembly of the crankshaft demands exacting tol-

erances, the disassembly and reassembly of the crankshaft

can only be done by a shop having the necessary tools and

equipment.

•

If it should be necessary to disassemble the crankshaft,

use a press to remove the crankpin.

Crankshaft Assembly

Since the assembly of the crankshaft demands exacting

tolerances, the disassembly and reassembly of the c rank-

shaft can only be done by a shop having the necessary tools

and equipment.

•

Reassemble the crankshaft according to the standard tol-

erances in Specifications.

○

Connecting rod bend, twist

○

Connecting rod big end radial clearance.

○

Cold-fitting tolerance between crankpin and flywheels.

○

Side clearance between the c onnecting rod big end and

one of flywheels.

○

Crankshaft runout.

ENGINE BOTTOM END/TRANSMISSION 8-13

Crankshaft, Connecting Rod

Connecting Rod Big En d Radial Clearance

•

Set the crankshaft in a flywheel alignment jig or on V

blocks, and place a dial gauge against the connecting rod

big end.

•

Push the connecting rod first towards the gauge and then

in the opposite direction. The difference between the two

gauge readings is the radial clearance.

If the radial clearance exceeds the service limit, the crank-

shaft should be either replaced or disassembled and the

crankpin, needle bearing, and connecting rod big end ex-

amined for wear.

Connecting Rod Big End Radial Clearance

Standard: 0.037 ∼ 0.049 mm (0.0015 ∼ 0.0019 in.)

Service Limit: 0.10 mm (0.004 in.)

Connecting Rod Big End Seizure

In case of serious seizure with damaged flywheels, the

crankshaft must be replaced.

In case of less serious damage, disassemble the crank-

shaft and replace the crankpin, needle bearing, side

washers, and connecting rod.

Connecting Rod Big End Sid e Clearance

•

Measure the side clearance [A] of the connecting rod with

a thickness gauge.

If the clearance exceeds the service limit, replace the

crankshaft.

Connecting Rod Big End Side Clearance

Standard: 0.45 ∼ 0.55 mm (0.0177 ∼ 0.0217 in.)

Service Limit: 0.70 mm (0.028 in.)

Crankshaft Runout

•

Set the crankshaft in a flywheel alignment jig or on V

blocks, and place a dial gauge against the points indi-

cated.

•

Turn the crankshaft slowly. The maximum difference in

gauge readings is the crankshaft runout.

If the runout at either point exceeds the service limit, align

the flywheels so that the runout falls within the service

limit.

Crankshaft Runout

Standard: TIR 0.03 mm (0.0012 in.) or less

Service Limit: TIR 0.05 mm (0.002 in. )

(A): 8.5 mm (0.335 in.)

8-14 ENGINE BOTTOM END/TRANSMISSION

Crankshaft, Connecting Rod

Crankshaft Alignment

•

In the case of horizontal misalignment, which is the most

common, strike the projecting rim of the flywheel with a

plastic, soft lead, or brass hammer as indicated in the

figure.

•

Recheck the runout with a dial gauge, repeating the

process until the runout falls within the service limit.

○

Vertical misalignment is corrected either by driving a

wedge in between the flywheels or by squeezing the

flywheel rims in a vise, depending on the nature of the

misalignment. In cases of both horizontal and vertical

misalignment, correct the horizontal misalignment first.

CAUTION

Don’t hammer the flywheel at point “A”.

If flywheel misalignment cannot be corrected by the above

method, replace the crankpin or the crankshaft itself.

ENGINE BOTTOM END/TRANSMISSION 8-15

Transmission

Shaft Removal

•

Split the crankcase (see Crankcase Splitting).

•

Pull off the shift rods [A], and disengage the shift fork

guide pins from the shift drum grooves.

•

Remove the shift drum [B]

•

Remove the shift forks [C] from the transmission gears.

•

Take out the drive shaft [D] and output shaft [E] together,

with their gears meshed.

Shaft Installation

•

Hold the drive shaft [A] and output shaft [B] together, with

their gears meshed, and fit them into the right crankcase

half.

•

To install the shift forks and shift drum (see Shift Drum

and Fork Installation).

Shaft Disassembly

•

Remove the transmission shafts (see Shaft Removal).

•

Using circlip pliers to remove the circlips, disassemble the

transmission shaft.

Special Tool - Outside Circlip Pliers: 57001-144

Shaft Assembly

•

Apply engine oil liberally to the transmission shaft, gears

and bearings.

•

Replace any circlips that were removed with new ones.

○

Always install circlips [A] so that the opening [B] is aligned

withasplinegroove[C].

Special Tool - Outside Circlip Pliers: 57001-144

•

The drive shaft gears can be identified by s ize; the small-

est diameter gear is 1st gear, and the largest is 5th. Be

sure that all parts are put back in the correct sequence,

and facing the proper direction, and that all circlips and

the washers are properly in place.

A. 1st gear (15T; part of drive shaft)

B. 5th gear (23T; dog recesses face left)

C. 3rd gear (17T; fork groove goes to the left side of the

gear teeth)

D. 4th gear (21T; dog recesses face right)

E. 2nd gear (16T; chamfered side faces right)

F. Circlip

•

The output shaft gears can be identified by size; the

largest diameter gear is 1st gear, and the s mallest is

5th. Be sure that all parts are put back in the correct

sequence and facing the proper direction, and that all

circlips are properly in place.

8-16 ENGINE BOTTOM END/TRANSMISSION

Transmissio n

A. 2nd gear (23T; dog recesses face right)

B. 4th gear (21T; fork groove goes to the right side of the

gear teeth)

C. 3rd gear (20T; dog recesses face left)

D. 5th gear (20T; fork groove goes to the left side of the

gear teeth)

E. 1st gear (27T; dog recesses face left)

F. Circlip

G. Collar

•

Check that each gear spins or slides freely on the trans-

mission shaft without binding after assembly.

Shift Drum and Fork Installation

•

Apply a little transmission oil to the shift fork [A] ears, and

fit the shift forks into the gear grooves.

Drive shaft 3rd gear and 4th

gear shift fork [A]

ears are shorter than those of the

other two shift forks

Output shaft 4th gear shift

fork [B]

guide pin goes to center side of

the ears

Output shaft 5th gear shift

fork [C]

guide pin goes to left side of the

ears

•

Tighten the shift drum bearing retaining screws or bolts.

Torque - Shift Drum Bearing Retaining bolts: 8.8 N·m (0.90

kgf·m, 78 in·lb)

•

Install the shift dram [A].

•

Fit the shift fork guide pins into the corresponding shift

drum grooves.

•

Apply a little engine oil to the shift rods [A], and slide them

into the shift forks [B].

•

Holding the shift drum with the suitable too and tighten

the shift drum operating plate bolt.

Torque - Shift Drum Operating Cam Bolt: 24 N·m (2.4 kgf·m,

17 ft·lb)

ENGINE BOTTOM END/TRANSMISSION 8-17

Transmission

Shift Fork Bending

•

Visually inspect the shift forks, and replace any fork that is

bent. A bent fork could cause difficulty in s hifting, or allow

the transmission to jump out of gear when under power.

A. 90°

Shift Fork/Gear Groove Wear

•

Measure the thickness of the shift fork ears [A], and mea-

sure the width [B] of the shift fork grooves in the transmis-

sion gears.

If the thickness of a shift fork ear is less than the service

limit, the shift fork must be replaced.

Shift Fork Ear Thickness

Standard: 4.40 ∼ 4.50 mm (0.1732 ∼ 0.1772 in.)

Service Limit: 4.3 m m (0.169 in.)

If a gear shift fork groove is worn over the service limit,

the gear must be replaced.

Shift Fork Groove Width

Standard: 4.55 ∼ 4.65 mm (0.1791 ∼ 0.1830 in.)

Service Limit: 4.75 mm (0.187 in.)

Shift Fork Guide Pin/Shift Drum Groove We ar

•

Measure the diameter [A] of each shift fork guide pin, and

measure the width [B] of each shift drum groove.

If the guide pin on any shift fork is less than the service

limit, the fork must be replaced.

Shift Fork Guide Pin Diameter

Standard: 5.90 ∼ 6.00 mm (0.2323 ∼ 0.2362 in.)

Service Limit: 5.80 mm (0.228 in.)

If any shift drum groove is worn over the service limit, the

drum must be replaced.

Shift Drum Groove Width

Standard: 6.05 ∼ 6.20 mm (0.2382 ∼ 0.2440 in.)

Service Limit: 6.25 mm (0.246 in.)

Gear Damage

•

Visually inspect the gear teeth on the transmission gears.

Repair lightly damaged gear teeth with an oilstone. The

gear must be replaced if the teeth are badly damaged.

When gear is repaired or replaced, the driving gear should

also be inspected and repaired or replaced if necessary.

8-18 ENGINE BOTTOM END/TRANSMISSION

Transmissio n

Gear Dog/Gear Dog Hole Damage

•

Visually inspect the gear dogs [A] and gear dog holes [B].

Replace any damaged gears or gears w ith excessively

worn dogs or dog holes.

Ball Bearing Wear

•

Check the ball bearing on the crankcase.

Since the ball bearings are made to extremely close toler-

ances, the wear must be judged by feel rather than mea-

surement. Clean each bearing in a high flash-point sol-

vent, dry it (do not spin the bearing while it is dry), and oil

it with engine oil.

○

Spin the bearing by hand to check its condition.

If the bearing is noisy, does not spin smoothly, or has any

rough spots, replace it.

WHEELS/TIRES 9-1

Wheels/Tires

Table of Contents

Exploded View........................................................................................................................ 9-2

Specifications ......................................................................................................................... 9-4

Special Tools .......................................................................................................................... 9-5

Wheels (Rims) ........................................................................................................................ 9-6

Front Wheel Removal ....................................................................................................... 9-6

Front Wheel Installation .................................................................................................... 9-6

Rear Wheel Removal........................................................................................................ 9-7

Rear Wheel Installation..................................................................................................... 9-8

Wheels Inspection............................................................................................................. 9-9

Spoke Tightness Inspection.............................................................................................. 9-9

Rim Runout Inspection ...................................................................................................... 9-9

Axle Inspection..................................................................................................................9-10

Tires........................................................................................................................................ 9-11

Air Pressure Inspection/Adjustment.................................................................................. 9-11

Tires Inspection.................................................................................................................9-11

Tire Removal.....................................................................................................................9-11

Installation......................................................................................................................... 9-12

Hub Bearings.......................................................................................................................... 9-14

Hub Bearing Removal....................................................................................................... 9-14

Hub Bearing Installation.................................................................................................... 9-14

Hub Bearing Inspection..................................................................................................... 9-14

9-2 WHEELS/TIRES

Exploded View

WHEELS/TIRES 9-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Spoke Nipple 2.2 0.22 19 in·lb

2 Front Axle Nut 78 8.0 58

3 Front Axle Clamp Bolts 20 2.0 14.5 AL

4 Rear Axle Nut 110 11.0 80

5. Spoke

6. Front Tire

7. Rim

8. Front Axle

9. Swingarm

10. Rear Tire

11. Rear Axle

AL: Tighten the two clamp bolts alternately two times to ensure even tightening torque.

G: Apply grease.

R: Replacement Part

WL: Apply soap and water solution, or rubber lubricant.

9-4 WHEELS/TIRES

Specifications

Item Standard Service Limit

Wheels (Rims)

Rim Size:

Front 21 × 1.60 –––

Rear 19 × 2.15 –––

Rim Runout

Axial TIR 1.0 mm (0.039 in.) or less TIR 2 mm (0.079 in.)

Radial TIR 1.0 mm (0.039 in.) or less TIR 2 mm (0.079 in.)

Axle Runout/100 mm 0.1 mm (0.004 in.) 0.2 mm (0.008 in.)

Tires Air Pressure

Front and Rear 100 kPa (1.0 kgf/cm², 14 psi) –––

Tires

Standard Tire

Front:

Size 80/100-21 51M –––

Make BRIDGESTONE (EUR) DUNLOP

Type M401, Tube (EUR) D755F, Tube

Rear:

Size 110/90-19 62M –––

Make BRIDGESTONE (EUR) DUNLOP

Type

M402, Tube (EUR) D755, Tube

EUR: Europe Model

WHEELS/TIRES 9-5

Special Tools

Inside Circlip Plie r s:

57001-143

Rim Protector:

57001-1063

Bead Breaker Assembly:

57001-1072

Bearing Driver Set:

57001-1129

Jack:

57001-1238

9-6 WHEELS/TIRES

Wheels (Rims)

Front Wheel Removal

•

Using the jack [A] under the frame, and stabilize the mo-

torcycle.

Special Tool - Jack: 57001-1238

•

Unscrew the axle nut [A].

•

Loosen the left axle clamp bolts [B].

•

Loosen the right axle clamp bolts [A].

•

Place a stand under the engine to raise the front wheel

off the ground.

•

Remove the axle [B], and pull out the wheel. Take off the

collar [C] and cap [D] from each side of the front hub.

CAUTION

Do not lay the wheel on the ground with the disc

facing down. This can damage or warp the disc.

Place blocks under the wheel so the disc does not

touch the ground.

•

Insert a wood wedge between the disc brake pads this

prevents them from being moved out of their proper posi-

tion, should the brake lever be squeezed accidentally.

Front Wheel Installation

•

Apply grease to the seals.

•

Fit the projection on the cap to the groove on the collar.

•

Install the caps [B] collars [A] on the left (longer collar)

and right (shorter collar) side of the hub.

•

Insert the axle [C] from right side.

•

Unbolt the right axle clamp bolts [D] temporally.

•

Tighten the axle nut [E].

•

Tighten the left axle clamp bolts [F].

Torque - Front Axle Nut: 78 N·m (8.0 kgf·m, 58 ft·lb)

Left Axle Clamp Bolts : 20 N·m (2.0 kgf·m, 14.5

ft·lb)

NOTE

○

Tighten the two clamp bolts alternately two times to en-

sure even tightening torque.

WHEELS/TIRES 9-7

Wheels (Rims)

•

Remove the jack.

•

Before tightening the clamp bolts on the right fork leg,

pump the forks up and down [A] 4 or 5 times to allow the

right fork leg to find a neutral position on the front axle.

NOTE

○

Do not apply the front brake during this process to stop

the motorcycle from rolling forward. Put a block [B] in

front of the wheel to stop it from moving.

•

Tighten the right axle clamp bolts.

Torque - Front Axle Clamp Bolts: 20 N·m (2.0 kgf·m, 14.5

ft·lb)

NOTE

○

Tighten the two clamp bolts alternately two times to en-

sure even tightening torque.

•

Check the front brake for good braking power and no

brake drag.

WARNING

Do not attempt to drive the motorcycle until a full

brake lever is obtained by pumping the brake lever

until the pads are against the disc. The brake will

not function on the first application of the lever if

this is not done.

Rear Wheel Removal

•

Using the jack under the frame so that the rear wheel is

raised off the ground.

Special Tool - Jack: 57001-1238

•

Remove the clip [A] from the master link using pliers, and

free the drive chain [B] from the rear sprocket.

9-8 WHEELS/TIRES

Wheels (Rims)

•

Remove:

Disc Cover [A]

Cotter Pin [B]

Axle Nut [C]

•

Pullouttheaxle[D].

•

Move the rear wheel back w ith the rear caliper installed.

•

Take off the collar and cap from the each side of the rear

hub.

CAUTION

Do not lay the wheel on the ground with the disc

facing down. This can damage or warp the disc.

Place blocks under the wheel so the disc does not

touch the ground.

•

Insert a wood wedge between the brake pads. This pre-

vents them from being moved out of their proper position,

should the brake pedal be squeezed accidentally.

Rear Wheel Installation

•

Fit the brake holder stop [A] with the stop grooves [B]

against the swingarm stop space [C] with the stop pro-

jection [D].

•

Fit the projection on the cap to the groove on the collar.

•

Install the collars [A] on the left and right side of the hub.

•

Install the drive chain. Install the master link clip [A] so

that the closed end of the “U” [B] points in the direction of

chain rotation [C].

•

Check the drive chain slack (see Final Drive chapter).

•

Tighten the axle nut.

Torque - Rear Axle Nut: 110 N·m (11 kg·m, 80 ft·lb)

WHEELS/TIRES 9-9

Wheels (Rims)

•

Install the new cotter pin [A] and spread its end.

NOTE

○

When inserting the cotter pin, if the slots in the nut do

not align with the cotter pin hole in the axle shaft, tighten

the nut clockwise [B] up to next alignment.

○

It should be within 30 degree.

○

Loosen once tighten again when the s lot goes past the

nearest hole.

•

Bend the cotter pin [A] over the nut [B].

•

Install disc cover.

•

Check the rear brake for good braking power and no

brake drag.

WARNING

Do not attempt to drive the motorcycle until a full

brake pedal is obtained by pumping the brake pedal

until the pads are against the disc. The brake will

not function on the first application of the pedal if

this is not done.

Wheels Inspection

•

Place the jack under the frame so that the front/rear wheel

is raised off the ground.

Special Tool - Jack: 57001-1238

•

Spin the wheel lightly, and check for roughness or binding.

If roughness or binding is found, replace the hub bearings.

•

Visually inspect the front and rear axles for damage.

If axle is damaged or bent, replace it.

Spoke Tightness Inspection

•

Refer to the Spoke Tightness Inspection in the Periodic

Maintenance chapter.

Rim Runout Inspection

•

Refer to the Rim Runout Inspection in the Periodic Main-

tenance chapter.

9-10 WHEELS/TIRES

Wheels (Rims)

Axle Inspection

•

Visually inspect the front and rear axle for damages.

If the axle is damaged or bent, replace it.

•

Place the axle in V blocks that are 100 mm (3.937 in.) [A]

apart, and set a dial gauge on the axle at a point halfway

between the blocks. Turn the axle to measure the runout.

The difference between the highest and lowest dial read-

ings is the amount of runout.

If runout exceeds the service limit, replace the axle.

Axle Runout/100 mm (3.937 in.)

Standard: TIR 0.1 mm (0.004 in.) or less

Service Lim it: TIR 0.2 mm (0.008 in.)

WHEELS/TIRES 9-11

Tires

Air Pressure Inspection/Adjustment

•

Refer to the Air Pressure Inspection/Adjustment in the Pe-

riodic Maintenance c hapter.

Tires Inspection

•

Refer to the Tire Inspection in the Periodic Maintenance

chapter.

Tire Removal

CAUTION

Do not lay the wheel on the ground with the disc

facing down. This can damage or warp the disc.

Place blocks under the wheel so the disc does not

touch the ground.

•

Remove the wheel from the motorcycle (see Wheels Re-

moval).

•

To maintain wheel balance, mark [A] the valve stem posi-

tion on the tire with chalk so that the tire can be reinstalled

in the same position.

•

Remove the valve cap [B].

•

Take out the valve core [A] to let out the air.

•

Remove the valve stem nut [B].

○

When handling the rim, be careful not to damage the rim

flanges.

•

Loosen the bead protector nut [A].

•

Lubricate the tire beads and rim flanges on both sides with

a s oap and water solution or rubber lubricant. This helps

the tire beads slip off the rim flanges.

CAUTION

Never lubricate with mineral oil (engine oil) or gaso-

line because they will cause deterioration of the tire.

•

Break the beads away from both sides of the rim with the

bead breaker [A].

Special Tool - Bead Breaker Assembly: 57001-1072

9-12 WHEELS/TIRES

Tires

•

Step on the side of the tire opposite v alve stem, pry the

tire off the rim with the tire iron [A] of the bead breaker

protecting the rim with rim protectors [B].

Special Tools - Rim Protector: 57001-1063

Bead Breaker Assembly: 57001-1072

CAUTION

Take care not to inset the tire irons so deeply that

the tube gets damaged.

•

Remove the tube when one side of the tire is pried off.

•

Pry the tire off the rim.

Installation

•

Inspect the rim and tire, and replace them if necessary.

•

Install the tube band and tube.

•

Apply a soap and water solution, or rubber lubricant to the

rim flange and tire beads.

•

Position the tires on the rims so that the serial numbers

[A] face the left.

○

For the European model, position the tires on the rims so

that the indications of manufacture week [A] face the left.

WHEELS/TIRES 9-13

Tires

•

Position the tire on the rim so that the valve [A] is at the tire

balance mark [B] (the chalk mark made during removal,

or the y ellow paint mark on a new tire. see Removal).

•

Insert the valve stem into the rim, and screw the nut on

loosely.

•

Fit the rim protectors and use tire irons to install the tire

bead.

NOTE

○

To prevent rim damage, be sure to place the rim protec-

tors at any place the tire irons are applied.

•

Pry one side of the tire back onto the rim. Fit the bead

protector into the tire.

•

Pry the other side of the tire onto the rim, starting at the

side opposite the valve.

○

Take care not to insert the tire irons so deeply that the

tube is damaged.

•

Install the other side of the tire bead onto the rim in the

same manner.

•

Check that the tube is not pinched between the tire and

rim.

•

Tighten the bead protector nut [A] and valve stem nut [B],

and put on the valve cap [C].

•

Check and adjust the air pressure after installing.

9-14 WHEELS/TIRES

Hub Bearings

Hub Bearing Removal

•

Remove the wheel (see Wheel Removal).

CAUTION

Do not lay the wheel on the ground with the disc

facing down. This can damage or warp the disc.

Place blocks under the w heel so that the disc does

not touch the ground.

•

Remove the oil seals and circlip.

•

Remove the hub bearing by tapping evenly around the

bearing inner race as shown.

Bar [A]

Distance Collar [B]

Hub Bearing [C]

Hub Bearing Installation

•

Before installing the wheel bearings, blow any dirt or for-

eign particles out of the hub [B] with compressed air to

prevent contamination of the bearings.

•

Replace the bearings with new ones.

•

Lubricate them and install them using the bearing driver

set [A] so that the marked or shielded s ides face out.

○

Press in the bearings until they are bottomed.

Special Tool - Bearin g Driver Set: 57001-1129

•

Replace the circlips and oil seals with new ones.

•

Press in the oil seals [A] so that the seal surface is flush

[B] with the end of the hole.

•

Apply high temperature grease to the oil seal lips.

Special Tool - Bearing Driver set : 57001-1129 [C]

Hub Bearing Inspection

NOTE

○

It is not necessary to remove any bearings for inspec-

tion. If any bearings are removed, they will need to be

replaced with new ones.

•

Spin [A] it by hand to check its condition.

If it is noisy, does not spin smoothly, or has any rough

spots, it must be replaced.

•

Examine the bearing seal [B] for tears or leakage.

If the seal is torn or is leaking, replace the bearing.

FINAL DRIVE 10-1

Final Drive

Table of Contents

Exploded View........................................................................................................................ 10-2

Specifications ......................................................................................................................... 10-4

Special Tools .......................................................................................................................... 10-5

Drive Chain............................................................................................................................. 10-6

Drive Chain Slack Inspection ............................................................................................ 10-6

Drive Chain Slack Adjustment .......................................................................................... 10-6

Wheel Alignment Inspection ............................................................................................. 10-6

Wheel Alignment Adjustment............................................................................................ 10-6

Drive Chain Wear Inspection ............................................................................................ 10-6

Drive Chain Lubrication..................................................................................................... 10-6

Drive Chain Removal ........................................................................................................ 10-6

Drive Chain Installation ..................................................................................................... 10-6

Drive Chain Guide Roller Wear......................................................................................... 10-7

Sprockets................................................................................................................................ 10-8

Engine Sprocket Removal ................................................................................................ 10-8

Engine Sprocket Installation ............................................................................................ 10-8

Rear Sprocket Removal.................................................................................................... 10-8

Rear Sprocket Installation................................................................................................. 10-9

Sprocket Wear Inspection................................................................................................. 10-9

Rear Sprocket Warp Inspection ........................................................................................ 10-9

10-2 FINAL DRIVE

Exploded View

FINAL DRIVE 10-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Rear Sprocket Nuts 34 3.5 25

2 Rear Axle Nut 110 11.0 80

3 Engine Sprocket Cover Bolts 8.8 0.90 78 in·lb

4. Engine Sprocket

5. Output Shaft

6. Chain Slipper

7. Swingarm

8. Chain Guide

9. Locknut

10. Adjusting Bolt

11. Chain Adjuster

12. Drive Chain

13. Rear Sprocket

14. Rear Axle

15. Upper Chain Guide Roller

16. Lower Chain Guide Roller

G: Apply grease.

O: Apply oil.

R: Replacement Part

10-4 FINAL DRIVE

Specifications

Item Standard Service Limit

Drive Chain

Chain Slack 52 ∼ 62 mm (2.05 ∼ 2.44 in.) –––

Chain 20-link Length 317.5 ∼ 318.2 mm (12.50 ∼ 12.53 in.) 323 mm (12.72 in.)

Standard Chain:

Make

DAIDO

–––

Type DID 520DMA2 –––

Length 114 Links –––

Sprocket

Engine Sprocket Diameter 55.48 ∼ 55.68 mm (2.184 ∼ 2.192 in.)/13T 54.8 mm (2.157 in.)

Rear Sprocket Diameter 247.64 ∼ 248.14 mm (9.750 ∼ 9.769 in.)/51T 247.3 mm (9.736 in.)

Rear Sprocket Runout TIR 0.4 mm (0.016 in.) or less TIR 0.5 mm (0.020 in.)

FINAL DRIVE 10-5

Special Tools

Outside Circlip Pliers:

57001-144

Jack:

57001-1238

10-6 FINAL DRIVE

Drive Chain

Drive Chain Slack Inspection

•

Refer to the Drive Chain Slack Inspection in the Periodic

Maintenance chapter.

Drive Chain Slack Adjustment

•

Refer to the Drive Chain Slack Adjustment in the Periodic

maintenance chapter.

Wheel Alignment Inspection

•

Check that the notch [A] on the left chain adjuster aligns

with the same swing arm mark [B] as the right chain ad-

juster.

WARNING

Misalignment of the wheel will result in abnormal

wear, and may result in an unsafe riding condition.

Wheel Alignment Adjustment

This p rocedure is the same as Drive Chain Slack Adjust-

ment.

Drive Chain Wear Inspection

•

Refer to the Drive Chain Wear Inspection in the Periodic

Maintenance chapter.

Drive Chain Lubrication

•

Refer to the Drive Chain Lubrication in the Periodic Main-

tenance chapter.

Drive Chain Removal

•

Remove the engine sprocket cover and the drive chain

guide (see Engine Sprocket Removal in this chapter).

•

Remove the clip [A] from the master link using pliers, and

free the drive chain from the rear sprocket.

•

Remove the drive chain from the chassis.

Drive Chain Installation

•

Fit the drive chain back onto the sprockets with the ends

at the rear sprocket.

•

Install the master link [A] from the frame side.

•

Install the link plate [B] so that the mark faces out.

Clip [C]

FINAL DRIVE 10-7

Drive Chain

•

Install the clip [A] so that the closed end of the “U” [B]

pointed in the direction of chain rotation [C].

•

Adjust the drive chain slack (see Drive Chain Slack Ad-

justment).

•

Check the rear brake (see the Brakes chapter).

Drive Chain Guide Roller Wear

•

Visually inspect the upper and lower chain guide rollers

[A] and replace them if excessively worn or damaged.

10-8 FINAL DRIVE

Sprockets

Engine Sprocket Removal

•

Remove:

Engine Sprocket Cover B olts [A]

Engine Sprocket Cover [B]

Drive Chain Guide [C]

•

Remove:

Drive Chain [A] (free of engine sprocket)

•

Remove the circlip [B], and pull off the engine sprocket

[C].

Special Tool - Out side Circ lip Pliers : 57001-144

Engine Sprocket Installation

•

Install the engine sprocket so that the flatten side faces

[A] inside.

•

Replace the circlip with a new one.

•

Install the circlip so that the tooth is aligned with a spline

groove.

Special Tool - Out side Circ lip Pliers : 57001-144

•

Tighten:

Torque - Engine Sprocket Cover Bolts: 8.8 N·m (0.90 kgf·m,

78 in·lb)

Rear Sprocket Removal

•

Remove the rear wheel (see Wheels/Tires chapter).

CAUTION

Do not lay the wheel on the ground with the disc

facing down. This can damage or warp the disc.

Place blocks under the w heel so that the disc does

not touch the ground.

•

Unscrew the rear sprocket bolts [A], and remove the rear

sprocket [B].

FINAL DRIVE 10-9

Sprockets

Rear Sprocket Installation

•

Install the rear sprocket [A] so that the marked side [B]

faces out.

•

Install the rear sprocket bolts and tighten the nuts.

Torque - Rear Sprocket Nuts: 34 N·m (3.5 kgf·m, 25 ft·lb)

Sprocket Wear Inspection

•

Refer to the Sprocket Wear Inspection in the Periodic

Maintenance chapter.

Rear Sprocket Warp Inspection

•

Refer to the Rear Sprocket Warp Inspection in the Peri-

odic Maintenance c hapter.

BRAKES 11-1

Brakes

Table of Contents

Exploded View........................................................................................................................ 11-2

Specifications ......................................................................................................................... 11-6

Special Tools .......................................................................................................................... 11-7

Brake Lever, Brake Pedal....................................................................................................... 11-8

Brake Lever Adjustment.................................................................................................... 11-8

Brake Pedal Position Adjustment...................................................................................... 11-8

Brake Pedal Removal ....................................................................................................... 11-8

Brake Pedal Installation .................................................................................................... 11-8

Brake Fluid ............................................................................................................................. 11-9

Fluid Level Inspection ....................................................................................................... 11-9

Fluid Change.....................................................................................................................11-9

Bleeding the Brake Line.................................................................................................... 11-10

Caliper .................................................................................................................................... 11-12

Caliper Removal ............................................................................................................... 11-12

Caliper Installation ............................................................................................................ 11-13

Caliper Disassembly ......................................................................................................... 11-13

Caliper Assembly .............................................................................................................. 11-13

Fluid Seal Damage ........................................................................................................... 11-13

Dust Seal and Cover Damage .......................................................................................... 11-13

Piston Cylinder Damage ................................................................................................... 11-13

Caliper Holder Shaft Wear ................................................................................................ 11-14

Brake Pad Removal .......................................................................................................... 11-14

Brake Pad Installation ....................................................................................................... 11-15

Brake Pad Inspection........................................................................................................ 11-15

Master Cylinder ...................................................................................................................... 11-16

Front Master Cylinder Removal ........................................................................................ 11-16

Front Master Cylinder Installation ..................................................................................... 11-16

Rear Master Cylinder Removal......................................................................................... 11-17

Rear Master Cylinder Installation...................................................................................... 11-17

Front Master Cylinder Disassembly .................................................................................. 11-17

Rear Master Cylinder Disassembly ................................................................................... 11-17

Master Cylinder Assembly ................................................................................................ 11-17

Master Cylinder Inspection (Visual Inspection)................................................................. 11-18

Brake Disk .............................................................................................................................. 11-19

Brake Disc Inspection ....................................................................................................... 11-19

Brake Hose............................................................................................................................. 11-20

Brake Hose Removal/Installation...................................................................................... 11-20

Brake Hose Inspection...................................................................................................... 11-20

11-2 BRAKES

Exploded View

BRAKES 11-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Front Master Cylinder Clamp Bolts 8.8 0.90 78 in·lb

2 Brake Hose Banjo Bolts 25 2.5 18

3 Brake Pad Bolt 18 1.8 13

Caliper Bleed Valve

7.8 0.8 69 in·lb

5 Caliper Mounting Bolts 25 2.5 18

6 Brake Disc Mounting Bolts 9.8 1.0 87 in·lb L

7. Front Brake Reservoir

8. Brake Lever

9. Brake Lever Adjuster

10. Locknut

11. Brake Hose

12. Clamps

13. Front Caliper

14. Brake Pad

15. Piston

16. Front Disc (KX250-R1)

17. Front Disc (KX250R6F ∼)

A: KX250-R1 ∼ R6F

B: Apply brake fluid.

R: Replacement Parts

Si: Apply Silicone grease.

11-4 BRAKES

Exploded View

BRAKES 11-5

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Brake Hose Banjo Bolts 25 2.5 18

2 Rear Master Cylinder Mounting Bolts 9.8 1.0 87 in·lb

3 Rear Master Cylinder Push Rod Locknut 18 1.8 13

4 Caliper Bleed Va lve 7.8 0.8 69 in·lb

5 Brake Pad Bolt 18 1.8 13

6 Rear Brake Pad Bolt Plug 2.5 0.25 22 in·lb L

Caliper Holder Shaft

27 2.8 20

8 Brake Pedal Mounting Bolt 25 2.5 18

9 Brake Disc Mounting Bolts 23 2.3 16.6 L

10. Brake Hose

11. Rear Master Cylinder

12. Brake Pedal

13. Rear Caliper Cover

14. Rear Caliper

15. Piston

16. Brake Pad

17. Rear Disc

B: Apply brake fluid.

EO: Apply engine oil

G: Apply high temperature grease.

L: Apply a non-permanent locking agent.

R: Replacement Parts

Si: Apply silicone grease.

11-6 BRAKES

Specifications

Item Standard Service Limit

Brake Adjustment

Lever Play

Adjustable (to suit rider)

–––

Brake Fluid

Recommended Disc Brake Fluid: –––

Grade:

Front DOT3 or DOT4 –––

Rear DOT4

Brake Pads

Lining Thickness:

Front 3.8 mm (0.150 in.) 1 mm (0.04 in.)

Rear 6.4 mm (0.252 in.) 1 mm (0.04 in.)

Brake Disc

Thickness:

Front

2.85 ∼ 3.15 mm (0.112 ∼ 0.124 in.) 2.5 mm (0.10 in.)

Rear 3.85 ∼ 4.15 mm (0.152 ∼ 0.163 in.) 3.5 mm (0.14 in.)

Runout TIR 0.25 mm (0.098 in.) or less TIR 0.3 mm (0.01 in.)

BRAKES 11-7

Special Tools

Inside Circlip Plie r s:

57001-143

Jack:

57001-1238

11-8 BRAKES

Brake Lever, B rake Pedal

Brake Lever Adjustment

•

Refer to the Brake Lever and Pedal Position Adjustment

in the Periodic Maintenance chapter.

Brake Pedal Position Adjustment

•

Refer to the Brake Lever and Pedal Position Adjustment

in the Periodic Maintenance chapter.

Brake Pedal Removal

•

Remove:

Cotter Pin [A]

Joint Pin [B]

Washer

•

Remove the mounting bolt [A] and take off the brake pedal

and return spring [B].

Brake Pedal Installation

•

Replace O-rings with new one and apply high tempera-

ture grease to the O-rings.

•

Apply high temperature grease to the shaft portion of the

brake pedal, and install the pedal with return spring onto

the frame.

○

Install the return spring [A] as shown.

Torque - Brake Pedal Mounting Bolt: 25 N·m (2.5 kgf·m, 18

ft·lb)

•

Check the brake pedal position.

•

Install the joint pin, washer and a new cotter pin.

○

Bend the ends [A] of the cotter pin.

BRAKES 11-9

Brake Fluid

WARNING

When working with the disc brake, observe the pre-

cautions listed below.

1. Never reuse old brake fluid.

2. Do not use fluid from a container that has been left

unsealed or that has been open for a long time.

3. Do not mix two types and brands of fluid for use in

the brake. This lowers the brake fluid boiling point

and could cause the brake to be ineffective. It may

also cause the rubber brake parts to deteriorate.

4. Don’t leave the reservoir cap off for any length of

time to avoid moisture contamination of the fluid.

5. Don’t change the fluid in the rain or when a strong

wind is blowing.

6. Except for the disc pads and disc, use only disc

brake fluid, isopropyl alcohol, or ethyl alcohol for

cleaning of the brake parts. Do not use any other

fluid for cleaning these parts. Gasoline, engine oil,

or any other petroleum distillate will cause deterio-

ration of the rubber parts. Oil spilled on any part will

be diff icult to wash off completely and will eventually

deteriorate the rubber used in the disc brake.

7. When handling the disc pads or disc, be careful that

no disc brake fluid or any oil gets on them. Clean off

any fluid or oil that inadvertently gets on the pads or

disc with a high flash-point solvent. Do not use one

which will leave an oily residue. Replace the pads

with new ones if they cannot be cleaned satisfacto-

rily.

8. Brake fluid quickly ruins painted surfaces; any

spilled fluid should be completely wiped up imme-

diately.

9. If any of the brake line fittings or the bleed valve is

opened at any time, the AIRMUSTBEBLEDFROM

THEBRAKELINE.

Fluid Level Inspection

•

Refer to the Brake Fluid Level Inspection in the Periodic

Maintenance chapter.

Fluid Change

•

Refer to the Brake Fluid Change in the Periodic Mainte-

nance chapter.

11-10 BRAKES

Brake F luid

Bleeding the Brake Line

The brake fluid has a very low compression coefficient so

that almost all the movement of the brake lever or pedal

is transmitted directly to the caliper for braking action. Air,

however, is easily compressed. When air enters the brake

lines, brake lever or pedal movement will be partially used

in compressing the air. This will make the lever or pedal feel

spongy, and there will be a loss in braking power.

WARNING

Be sure to bleed the a ir from the brake whenever

brake lever or pedal action feels soft or spongy, af-

ter the brake fluid is changed, or whenever a brake

line fitting has been loosened for any reason.

NOTE

○

The procedure to bleed the front brake line is as follows.

Bleeding the rear brake line is the same as for the front

brake.

•

Remove the reservoir cap, and check that there is plenty

of fluid in the reservoir.

•

With the reservoir cap off, slowly pump the brake lever

several times until no air bubbles can be seen rising up

through the fluid from the holes at the bottom of the reser-

voir.

○

Bleed the air completely from the master cylinder by this

operation.

•

Install the reservoir c ap.

•

Attach a clear plastic hose to the bleed valve on the

caliper, and run the other end of the hose into a con-

tainer.

•

Bleed the brake line and the caliper as follows:

○

Repeat this operation until no more air can be seen com-

ing out into the plastic hose.

1. Pump the brake lever until it becomes hard, and apply

the brake and hold it [A].

2. Quickly open and close the bleed valve while holding the

brake applied [B].

3. Release the brake [C].

NOTE

○

The fluid level must be checked often during the bleed-

ing operation and replenished with fresh brake fluid as

necessary. If the fluid in the reservoir runs almost out

any time during bleeding operation, the bleeding opera-

tion must be done over again from the beginning since

air will have entered the line.

○

Tap the brake hose lightly from the caliper to the reser-

voir for easier bleeding.

BRAKES 11-11

Brake Fluid

•

Remove the clear plastic hose.

•

Tighten the bleed valves, and install the rubber caps.

Torque - Caliper Bleed Valve: 7.8 N·m (0.8 kgf·m, 69 in·lb)

•

Check the fluid level.

•

After bleeding is done, check the brake for good braking

power, no brake drag, and no fluid leakage.

WARNING

Do not attempt to drive the motorcycle until a full

brake lever or pedal is obtained by pumping the

brake lever or pedal until the pads are against the

disc. The brake will not function on the first appli-

cation of the lever or pedal if this in not done.

11-12 BRAKES

Caliper

Caliper Removal

Front Brake

•

Loosen the banjo bolt [A] so as not to spill brake fluid.

•

Remove the caliper mounting bolts [B].

•

Remove the banjo bolt and take off the brake hose from

the caliper [C].

•

If the caliper is to be disassembled after removal and if

compressed air is not available, remove the piston using

the following steps before disconnecting the brake hose

from the caliper.

○

Remove the pads.

○

Pump the brake lever to remove the piston.

Rear Brake

•

Unbolt the guard bolts [A] and remove the rear caliper

guard [B].

•

Loosen the banjo bolt [C] so as not to spill brake fluid.

•

Remove the brake pad bolt plug.

•

Loosen the brake pad bolt [A] and caliper holder shaft [B]

before the caliper removal if the caliper is to be disassem-

bled.

NOTE

○

If the caliper is to be disassembled after removal and

compressed air is not available, disassemble the caliper

before brake hose removal (see Caliper Disassembly).

•

Remove the rear wheel. (see Wheels/Tires chapter)

•

Unscrew the banjo bolt and remove the brake hose [C]

from the caliper (see Brake Hose Removal/Installation).

CAUTION

Immediately wipe up any brake fluid that is spilled.

BRAKES 11-13

Caliper

Caliper Installation

•

Tighten the brake pad bolts if it was removed.

Torque - B rake Pad Bolts: 18 N·m (1.8 kgf·m, 13 ft·lb)

Front Brake:

•

Install the caliper and tighten the bolts.

Torque - Caliper Mounting Bolts: 25 N·m (2.5 kgf·m, 18.0

ft·lb)

Rear Brake:

•

Before install the caliper, install the rear wheel (see

Wheels/Tires chapter).

•

Install the brake hose lower end.

○

Replace the washers that are on each side of hose fitting

with new ones.

Torque - Brake Hose Banjo Bolt: 34 N·m (3.5 kgf·m, 25 ft·lb)

•

Bleed the brake line (see Bleeding the Brake Line).

•

Check the brake for good braking power, no brake drag,

and no fluid leakage.

WARNING

Do not attempt to drive the motorcycle until a full

brake lever or pedal is obtained by pumping the

brake lever or pedal until the pads are against the

disc. The brakes will not function on the first appli-

cation of the lever or pedal if this is not done.

Caliper Disassembly

•

Refer to the Caliper Piston Seal and Dust Seal Replace-

ment in the Periodic Maintenance chapter.

Caliper Assembly

•

Refer to the Caliper Fluid Seal and Dust Seal Replace-

ment in the Periodic Maintenance chapter.

Fluid Seal Damage

The fluid seal around the piston maintains the proper

pad/disc clearance. If this seal is not in good condition,

pad wear will increase, and constant pad drag on the disc

will raise brake and brake fluid temperature.

•

Replace the fluid seals under any of the following condi-

tions: (a) fluid leakage around the pad; (b) brakes over-

heat; (c) there is a large difference in left and right pad

wear; (d) the seal is stuck to the piston. If the fluid seal is

replaced, replace the dust seal as well. Also, replace all

seals every other time the pads are changed.

Dust Seal and Cover Damage

•

Check that the dust seals and covers are not cracked,

worn, swollen, or otherwise damaged.

If they show any damage, replace them.

Piston Cylinder Damage

•

Visually inspect the piston and cylinder surfaces.

Replace the cylinder and piston if they are badly scored

or rusty.

11-14 BRAKES

Caliper

Caliper Holder Shaft Wear

The caliper body must slide smoothly on the caliper holder

shafts. If the body does not slide smoothly, one pad will

wear more than the other, pad wear will increase, and con-

stant drag on the disc will raise brake and brake fluid tem-

perature.

•

Check too see if the caliper holder shafts are not badly

worn or stepped, or the rubber friction boot is not dam-

aged.

If the shafts or rubber friction boot are damaged, replace

the s hafts, rubber friction boot, and the caliper holder.

Brake Pad Removal

For Front Brake Pad

•

Unscrew the pad bolt [A].

•

Take the piston side pad [B].

•

Push the caliper holder toward the piston, and then re-

move another pad [C] from the caliper holder.

For Rear Brake Pad

•

Unscrew the caliper guard bolts [A] and remove the

caliper guard [B].

•

Remove the pad bolt plug.

•

Unscrew the pad bolt [A].

•

Take the piston side pad [B].

•

Push the caliper hold toward the piston, and then remove

another pad [C] from the caliper holder.

BRAKES 11-15

Caliper

Brake Pad Installation

•

Push the caliper pistons in by hand as far as they will go.

•

Install the piston side pad first, and then another pad.

○

Fit the pad end [A] into the groove [B] of the anti-rattle

spring securely.

•

Tighten the brake pad bolt.

Torque - Brake Pad Bolt: 18 N·m (1.8 kgf·m, 13 ft·lb)

•

Check the brake for good braking power, no brake drag,

and no fluid leakage.

WARNING

Do not attempt to drive the motorcycle until a full

brake lever or pedal is obtained by pumping the

brake lever or pedal until the pads are against the

disc. The brake will not function on the first appli-

cation of the lever or pedal if this is not done.

Brake Pad Inspection

•

Refer to the Brake Pad Wear Inspection in the Periodic

Maintenance chapter.

11-16 BRAKES

Master Cylinder

CAUTION

Brake fluid quickly ruins painted or plastic sur-

faces; any spilled fluid should be completely

wished up immediately.

Front Master Cylinder Removal

•

Remove the banjo bolt [A] to disconnect the upper brake

hose from the master cylinder (see Brake Hose Re-

moval/Installation).

•

When removing the brake hose, temporarily secure the

end of the brake hose to some high place to keep fluid

loss to a minimum.

•

Unscrew the clamp bolts [B], and take off the master cylin-

der [C] as an assembly with the reservoir and brake lever.

Front Master Cylinder Installation

KX250-R1:

•

Position the master cylinder so that the vertical parting

line [A] of the front master cylinder clamps align with the

punch mark [B] on the handlebar.

KX250R6F ∼:

•

Position the master cylinder so that the reserve tank cap

alien [A] to the frame horizontal line [B] as shown.

•

The master cylinder clamp must be installed with the ar-

row mark [A] upward.

○

Tighten the upper clamp bolt [B] first, and then the lower

clamp bolt [C] There w ill be a gap at the lower part of the

clamp after tightening.

Torque - Front Master Cylinder Clamp Bolts: 8.8 N·m (0.90

kgf·m, 78 in·lb)

•

Replace the washers that are o n each side of hose fitting

with new ones.

•

Tighten the brake hose banjo bolt.

Torque - Brake Hose Banjo Bolt: 25 N·m (2.5 kgf·m, 18 ft·lb)

•

Bleed the brake line (see Bleeding the Brake Line).

•

Check the brake for good braking power, no brake drag,

and no fluid leakage.

BRAKES 11-17

Master Cylinder

Rear Master Cylinder Removal

•

Remove the cotter pin [A].

•

Pull off the joint pin [B] with washer.

NOTE

○

Pull off the joint pin while pressing down the brake

pedal.

•

Unscrew the m aster cylinder mounting bolts [C], and re-

move the master cylinder [D].

•

Unscrew the brake hose banjo bolt [E].

•

When removing the brake hose, temporarily secure the

end of the brake hose to s ome high place to keep fluid

loss to a minimum.

Rear Master Cylinder Installation

•

Replace the cotter pin with a new one.

•

Replace the washers are on each side of hose fitting with

new ones.

•

Tighten the following:

Torque - Brake Hose Banjo Bolt: 25 N·m (2.5 kgf·m, 18 ft·lb)

Rear Master Cylinder Mounting Bolts: 9.8 N·m (1.0

kgf·m, 87 in·lb)

•

Bleed the brake line (see Bleeding the Brake Line).

•

Check the brake for good braking power, no brake drag,

and no fluid leakage.

•

Check the brake pedal position (master cylinder push rod

length).

Front Master Cylinder Disassembly

•

Refer to the Brake Master Cylinder Cup and Dust Cover

Replacement in the Periodic Maintenance chapter.

Rear Master Cylinder Disassembly

•

Refer to the Brake Master Cylinder Cup and Dust Cover

Replacement in the Periodic Maintenance chapter.

Master Cylinder Assembly

•

Refer to the Brake Master Cylinder Cup and Dust Cover

Replacement in the Periodic Maintenance chapter.

11-18 BRAKES

Master Cylinder

Master Cylinder Inspection ( Visual Inspection)

•

Disassemble the front and rear master cylinders.

•

Check that there are no scratches, rust or pitting on the

inner wall of each master cylinder [A] and on the outside

of each piston [B].

If a master cylinder or piston shows any damage, replace

them.

•

Inspect the primary [C] and secondary [D] cups.

If a cup is worn, damaged, softened (rotted), or swollen,

the piston assembly should be replace to renew the cups.

If fluid leakage is noted at the brake lever, the piston as-

sembly should be replaced to renew the cup.

•

Check the dust covers [E] for damage.

If they are damaged, replace them.

•

Check that the relief [F] and supply [G] ports are not

plugged.

If the small relief port becomes plugged, the brake pads

will drag on the disc. Blow the ports clean with com-

pressed air.

•

Check the piston return springs [H] for any damage.

If a spring is damaged, replace it.

[K] Rear Master Cylinder.

BRAKES 11-19

Brake Disk

Brake Disc Inspection

•

Visually inspect the disc [A].

If it is scratched or damaged, replace the disc.

•

Measure the thickness of each disc at the point [B] where

it has worn the most.

Replace the disc if it has worn past the service limit.

Thickness

Standard:

Front

2.85 ∼ 3.15 mm (0.112 ∼ 0.124 in.)

Rear

3.85 ∼ 4.15 mm (0.152 ∼ 0.163 in.)

Service Limit:

Front

2.5 mm (0.10 in.)

Rear

3.5 mm (0.14 in.)

•

Place a jack under the m otorcycle so that the front/rear

wheel is raised off the ground.

Special Tool - Jack: 57001-1238

•

Set up a dial gauge against the disc [A] as illustrated.

○

For the front disc, turn the handlebar fully to one side.

•

Measure the disc runout while rotating the wheel slowly

[B].

If the runout exceeds the service limit, replace the disc.

Runout

Standard: TIR 0.25 mm (0.098 in.) or less

Service Limit: TIR 0.3 mm (0.01 in.)

11-20 BRAKES

Brake H ose

Brake Hose Remo v al/Installation

•

Refer to the Brake Hose Replacement in the Periodic

Maintenance chapter.

Brake Hose Inspection

•

Refer to the Brake Hose and Connection Check in the

Periodic Maintenance chapter.

SUSPENSION 12-1

Suspension

Table of Contents

Exploded View................................... 12-2

Specifications .................................... 12-6

Special Tools ..................................... 12-8

Front Fork .......................................... 12-9

Air Pressure ................................. 12-9

Compression Damping

Adjustment ................................ 12-9

Rebound Damping Adjustment .... 12-10

Oil Change (each fork leg) ........... 12-10

Front Fork Removal ..................... 12-10

Front Fork Installation .................. 12-12

Front Fork Disassembly (each

fork leg) ..................................... 12-12

Front Fork Assembly.................... 12-16

Adjuster Assembly Inspection...... 12-22

Base Valve Assembly Inspection . 12-22

Cylinder Unit Inspection ............... 12-22

Inner Tube Inspection .................. 12-22

Guide Bush Inspection................. 12-23

Dust Seal/Oil Seal Inspection ...... 12-23

Spring Tension ............................. 12-23

Rear Suspension (Uni-Trak).............. 12-24

Rear Shock Absorber ..................... 12-24

Rebound Damping Adjustment .... 12-24

Compression Damping

Adjustment ................................ 12-25

Spring Preload Adjustment .......... 12-26

Spring Tension ............................. 12-27

Rear Shock Absorber Removal ... 12-27

Rear Shock Absorber Installation 12-27

Spring Replacement .................... 12-27

Rear Shock Absorber

Disassembly (Oil C hange) ........ 12-28

Rear Shock Absorber Assembly .. 12-28

Rear Shock Absorber Scrapping . 12-28

Swingarm........................................... 12-29

Swingarm Removal...................... 12-29

Swingarm Installation................... 12-30

Swingarm Bearing Removal ........ 12-30

Swingarm Bearing Installation ..... 12-30

Swingarm Bearing, Sleeve

Inspection.................................. 12-30

Tie-rod, Rocker Arm .......................... 12-31

Tie-rod Removal .......................... 12-31

Tie-rod Installation ....................... 12-31

Rocker Arm Removal................... 12-31

Rocker Arm Installation................ 12-32

Tie-rod and Rocker Arm Bearing

Removal.................................... 12-32

Tie-rod and Rocker Arm Bearing

Installation................................. 12-32

Needle Bearing Inspection........... 12-33

Uni-Trak Maintenance ....................... 12-34

Uni-Trak Linkage Inspection ........ 12-34

Tie-rod and Rocker Arm Sleeve

Wear.......................................... 12-34

Tie-rod and Rocker Arm Mounting

Bolt Bend................................... 12-34

12-2 SUSPENSION

Exploded View

SUSPENSION 12-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Base Valve Assembly 27 2.8 20

2 Front Fork Top Plug 29 3.0 22

3 Front Fork Clamp Bolts (Upper, Lower) 20 2.0 14.5 AL

Steering Stem Head Nut

78 8.0 58

5 Lock Nut/Adjuster Assembly 29 3.0 22

6 Adjuster Assembly 58 6.0 43 L

Front Axle Clamp Bolts

20 2.0 14.5 AL

8. Screw

9. O-ring

10. Piston Rod

11. Rebound Damping Adjuster Rod

12. Subtank

13. Cylinder Unit

14. Outer Tube

15. Collar

16. Spring

17. Collar

18. Bushings

19. Washer

20. Oil Seal

21. Retaining Ring

22. Dust Seal

23. Inner Tube

24. O-ring

25. Gasket

26. Steering Stem Head

27. Steering Stem

AL: Tighten the two clamp bolts alternately two times to ensure even tightening torque.

L: Apply a non-permanent locking agent to the threads.

R: Replacement Parts

A: KX250-R1 Model

B: KX250-R1, R6F

C: KX250R7F

12-4 SUSPENSION

Exploded View

SUSPENSION 12-5

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Swingarm Pivot Shaft Nut 98 10.0 72

2 Tie-rod Mounting Nut (Front, Rear) 83 8.5 61

3 Rocker Arm Pivot Nut 83 8.5 61

4 Rear Shock A bsorber Mounting Nut (Upper) 39 4.0 29

5 Rear Shock A bsorber Mounting Nut (Lower) 34 3.5 25

6. Pivot Shaft

7. Swingarm

8. Rocker Arm

9. Ti e-rod

10. Rear Shock Absorber Cylinder

11. Air Bleeder Bolt

12. O-ring

13. Bladder

14. Cap

15. Circlip

16. Valve Cap

17. Locknut

18. Adjusting Nut

19. Spring

20. Spring Guide

21. Circlip

22. Piston Rod Assembly

23. Piston

24. O-ring

25. Oil Seal

26. Stopper

27. Rear Shock Absorber

G: Apply grease.

12-6 SUSPENSION

Specifications

Item Standard Service Limit

Front Fork

Air Pressure: Atmospheric pressure –––

Rebound Damping Adjustment

(from the Seated Position Adjuster

Turned Fully Clockwise)

(Adjustable Range)

KX250-R1 12 clicks counterclockwise 16 clicks

KX250R6F ∼ 11 clicks counterclockwise

Compression Damping Adjustment

(from the Seated Position Adjuster

Turned Fully Clockwise)

(Adjustable Range)

KX250-R1 10 clicks counterclockwise 16 clicks

KX250R6F ∼ 11 clicks counterclockwise

Oil Viscosity KHL15-10 (KAYABA 01) or equivalent –––

Oil Quantity:

Outer (Outer/Inner Tubes) (Adjustable Range)

KX250-R1

300 mL (10.14 US oz)

280 ∼ 320 mL

(9.47 ∼ 10.82 US oz)

KX250R6F ∼ 310 mL (10.48 US oz) 290 ∼ 330 mL

(9.80 ∼ 11.16 US oz)

Inner (Subtank) 160 mL (5.41 US oz)

Fork Spring Free Length 465 mm (18.31 in.) 456mm(17.95in.)

Rear Suspension (Uni-Trak)

Rear Shock Absorber

Rebound Damping Adjustment

(from the Seated Position Adjuster

Fully Clockwise) Turned

(Adjustable Range)

KX250-R1 9 clicks counterclockwise 16 clicks

KX250R6F ∼ 10 clicks counterclockwise

Spring Preload Adjustment

(Adjusting Nut Position from the

Center of the Mounting Hole

Upper)

(Adjustable Range)

KX250-R1

120 mm (4.72 in.)

109 ∼ 129.5 mm

(4.29 ∼ 5.10 in.)

KX250R6F ∼ 118 mm (4.65 in.)

Rear Shock Spring Free Length 260 mm (10.24 in.) 255mm(10.04in.)

Gas Reservoir

Compression Damping Adjustment

(from the Seated Position Adjuster

Turned Fully Clockwise)

High Speed:

KX250-R1 ––– (Adjustable Range)

KX250R6F ∼ 1 1/4 turns out 0 ∼ 2 turns out

Low Speed

12 clicks counterclockwise 16 clicks

Gas Pressure 980 kPa (10 kgf/cm², 142 psi) –––

SUSPENSION 12-7

Specifications

Item Standard Service Limit

Tie-rod, Rocker Arm

Sleeve Outside Diameter:

Tie-rod 19.987 ∼ 20.000 mm

(0.7869 ∼ 0.7874 in.)

19.85 mm (0.781 in.)

Rocker Arm:

Large 19.987 ∼ 20.000 mm

(0.7869 ∼ 0.7874 in.)

19.85 mm (0.781 in.)

Small

15.95 ∼ 16.00 mm

(0.628 ∼ 0.630 in.)

15.91 mm (0.626 in.)

Rocker Arm Mounting Bolt Runout

under 0.1 mm (0.004 in.) 0.2 mm (0.008 in.)

12-8 SUSPENSION

Special Tools

Oil Seal & Bearing Re m over:

57001-1058

Steering Stem Nut Wrench:

57001-1100

Hook Wrench R37. 5, R42:

57001-1101

Bearing Driver Set:

57001-1129

Jack:

57001-1238

Bearing Rem o ver Shaft, 9:

57001-1265

Bearing Remover Head, 15 × 17:

57001-1267

Fork Oil Seal Driver, 48:

57001-1509

TopPlugWrench(46mm):

57001-1622

SUSPENSION 12-9

Front Fork

Air Pressure

The standard air pressure in the front fork legs is atmo-

spheric pressure. Air pressure in the fork legs increase

with normal use, so the fork action stiffens during opera-

tion. Release air pressure form the fork legs prior to each

race through the pressure relief screw located in each front

fork cap.

•

Place the jack under the frame so that the front wheel off

the ground.

Special Tool - Jack: 57001-1238

•

Remove the screws [A] at the top of the front fork top plugs

to let the air pressure equalize.

NOTE

○

Do not use the side stand when adjusting the air pres-

sure.

○

Adjust the air pressure when the front forks are cold.

•

Replace the O-rings of the screw with new ones.

•

Install the screw.

Compression Damping Adjustment

•

Place the jack under the frame so that the front wheel off

the ground.

Special Tool - Jack: 57001-1238

•

To adjust compression damping, turn the adjuster [A] on

the front fork top plugs with the blade of a screwdriver until

you feel a click. Adjust the compression damping to suit

you preference under special condition.

NOTE

○

The left and right fork legs must have the same shock

damping.

Seated positions: adjuster turned fully clockwise [A].

Compressio n Damping Adjuster Setting

Standard:

KX250-R1 10 clicks [B]

KX250R6F ∼ 11 clicks

Softer (Counterclockwise) [C]

Harder (Clockwise) [D]

*: Number of turns counterclockwise usable range-16

clicks or more.

CAUTION

Do not force the rebound and compression damp-

ing force adjusters beyond the fully seated position,

or the adjusting mechanism may be damaged.

12-10 SUSPENSION

Front Fork

Rebound Damping Adjustment

•

Place the jack under the frame so that the front wheel off

the ground.

Special Tool - Jack: 57001-1238

•

Clean the bottom of the fork tubes.

•

To adjust rebound damping, turn the adjuster [A] on the

front fork cylinder valve with the blade of a screwdriver

until you feel a click. Adjust the rebound damping to suit

your preference under special condition.

NOTE

○

The left and right fork legs must have the same shock

damping.

Seated positions adjuster turned fully clockwise [A].

Rebound Damping A djuster Setting

Standard:

KX250-R1 12 clicks [B]

KX250R6F ∼ 11 clicks

Softer (Counterclockwise) [C]

Harder (Clockwise) [D]

*: Number of turns c ounterclockwise usable range-16

clicks or more.

CAUTION

Do not force the rebound and compression damp-

ing force adjusters beyond the fully seated position,

or the adjusting mechanism may be damaged.

Oil Change (each fork leg)

•

Refer to the Front Fork Oil Change in the Periodic Main-

tenance chapter.

Front Fork Removal

•

Unscrew the bolts [A], and remove the front brake hose

clamps [B].

SUSPENSION 12-11

Front Fork

•

Remove:

Front wheel (see Wheels/Tires chapter)

Bolts [A]

•

Remove the caliper [B] from the fork leg to be removed,

and rest the caliper on some kind of stand so that it doesn’t

dangle.

•

Loosen the upper [A], and lower [B] fork clamp bolts.

•

Remove the front fork.

○

With a twisting motion [A], work the fork leg [B] down and

out.

•

Remove:

Bolts [A]

Fork Protector [B]

Guide [C] (KX250-R1, R6F)

Bolt [D] (KX250-R1, R6F)

12-12 SUSPENSION

Front Fork

Front Fork Installation

•

Install the fork so that the distance between the top end of

the outer tube and the upper surface of the steering stem

head is specified dimension.

[A] = 4 m m (0.16 in.)

•

Route the cables and hose according to the Cable, Har-

ness, Hose Routing section in the Appendix chapter.

•

Install the front wheel (see Wheels/Tires chapter).

•

Tighten the fork clamp bolts.

Torque - Fork Clamp Bolts: 20 N·m (2.0 kgf·m, 14.5 ft·lb)

NOTE

○

Tighten the two clamp bolts alternately two times to en-

sure even tightening torque.

•

Tighten:

Torque - Front Caliper Mounting Bolts: 25 N·m (2.5 kgf·m,

18 ft·lb)

•

Check the front brake operation after installation.

Front Fork Disassembly (each fork leg)

•

Loosen the front fork upper clamp bolts [A].

•

Loosen the fork top plug (subtank) [A] with the special

tool.

Special Tool - Top Plug Wrench, 46 mm: 57001-1622 [B]

•

Remove the front fork (see Front Fork Removal).

NOTE

○

Set rebound and compression damping setting to the

softest settings before disassembling to p revent the

needle of adjusters from damaging. Record the setting

before turning the adjuster.

•

Thoroughly clean the fork before disassembly.

CAUTION

Be careful not scratch the i nner tube and not to

damage the dust seal.

Avoid scratching or damaging the inner tube or the

dust seal. Use a mild detergent and sponge out dirt

with plenty of water.

SUSPENSION 12-13

Front Fork

•

Using the special tool [A], remove the fork top plug [B]

(subtank) from the outer tube and slowly slide down the

outer tube [C].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

•

Place a drain pan under the front fork and drain fork oil

[A].

NOTE

○

Pump the fork tube several times to discharge the fork

oil.

•

Raise the outer tube and temporarily install the fork top

plug [A] (subtank) to the outer tube [B] with the special

tool [C].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

•

Hold the axle holder [A] with a vise.

○

Protect the axle holder with a rag when using a vise.

•

Loosen the adjuster assembly [B] completely.

WARNING

Clamping the axle holder too tight can damage it

which will affect riding stability.

Do not clamp the axle holder too tight.

•

Compress the outer tube by hands and install the top plug

wrench (special tool) [A] between the axle holder bottom

[B] and lock nut [C].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

WARNING

Be careful of reaction force in spring and fix surely

so that the special tool should not come off. Do not

place the finger etc. while servicing.

12-14 SUSPENSION

Front Fork

•

Hold the locknut [A] with a wrench [B] and remove the

adjuster assembly [C].

•

Remove the push rod [A].

•

With the outer tube compressed by hands, remove the

top plug wrench (special tool) [A].

CAUTION

Removing the lock nut and pushing the piston rod

thread into the cylinder unit will damage the oil seal.

Do not remove the lock nut from the piston rod.

•

Remove the f ork leg from the vise.

•

Loosen the fork top plug (subtank) [A] with the special

tool.

Special Tool - Top Plug Wrench, 46 mm: 57001-1622 [B]

•

Remove:

Cylinder Unit [A]

Spring Collar [B] (KX250-R1)

Fork Spring [C]

Spring Collar [D]

CAUTION

Disassembling the cylinder unit can lead to trouble.

Do not disassemble the cylinder unit.

SUSPENSION 12-15

Front Fork

•

Remove the dust seal [A] and the retaining ring [B].

CAUTION

Be careful not to scratch the inner tube.

•

Grasp the outer tube and stroke [A] the inner tube several

times. The shock to fork seal separates the inner tube

from the outer tube.

•

Remove the following parts from the inner tube.

Guide Bushes [A]

Washer [B]

Oil Seal [C]

Retaining Ring [D]

Dust S eal [E]

•

Holding the top plug wrench [A] with a vise, loosen the

base assembly [B] on the subtank [C].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622 [B]

•

Remove the base valve assembly [A] from the subtank

[B].

NOTE

○

Slowly compress the piston rod until it stops so that the

base valve assembly can be removed easily.

CAUTION

Disassembling the base valve assembly can lead to

trouble.

Do not disassemble the base valve assembly.

12-16 SUSPENSION

Front Fork

•

Drain the fork oil [A] from the cylinder unit [B] by pumping

the piston rod several times

Front Fork Assembly

•

When the fork tubes are not disassembled, hold the fork

inverted position for more than 20 minutes to allow the

fork oil to fully drain.

•

Replace the following with new ones:

Dust Seal [A]

Retaining Ring [ B]

Oil Seal [C]

Guide Bushes [D]

•

Place an oil coated plastic bag [E] over the end of the

inner tube to protect the oil seals.

○

The inner tube guide bush groove has a sharp edge [F]

that can out the sealing lip of the seals as they as are

pushed down over the inner tube.

•

Install in order these parts on the inner tube.

•

When assembling the new outer tube guide bush [A], hold

the washer against the new one, and tap the washer with

the fork oil seal driver [B] until it stops.

Special Tool - Fork Oil Seal Driver, 48: 57001-1509

•

After installing the washer, install the oil seal by using the

fork oil seal driver.

Special Tool - Fork Oil Seal Driver, 48: 57001-1509

•

Install the retaining ring to the outer tube.

•

Push the dust seal into the outer tube, and put the s pring

band on the dust seal.

SUSPENSION 12-17

Front Fork

•

Clean the threads [A] of subtank and base valve assem-

bly.

•

With the piston rod in fully compressed position, pour the

specifiedamountofforkoil[A].

Recommended Oil: KHL15-10 (KAYABA01) or

equivalent

Recommended Quantity: 160 ml (5.41 US oz)

NOTE

○

Plug the two oil holes [B] on the subtank [C] with fingers.

•

Pump [A] the piston rod [B] slowly several times to expel

air.

•

Replace the O-rings [A] on the base valve assembly with

new ones.

•

Apply specified fork oil to the O-rings [A] [B] and bushings

[C] on the base valve assembly.

12-18 SUSPENSION

Front Fork

•

With the piston rod held immorable in fully compressed

position [A], gently install the base valve assembly [B] to

the s ubtank.

•

Screw in the base valve assembly in the subtank when

the piston rod extends.

NOTE

○

When it is hard to screw in the base valve assembly,

pull down the piston rod a little.

•

Holding the top plug wrench [A] (special tool) with a vise.

•

Holding the subtank [B] with the top plug wrench, torque

the base valve assembly [C].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

Torque - Base Valve Assembly: 27 N·m (2.8 kgf·m, 20 ft·lb)

•

Protect the piston rod end [A] with a rag [B] to prevent fork

damage.

•

Discharge the extra oil off the cylinder unit by pumping [C]

the piston rod to full stroke.

CAUTION

Be careful not to bend or damage the piston rod

when the piston rod is stroked. Service carefully

because oil flies out from the oil hole of the cylinder

unit.

NOTE

○

Set the compression damper setting to the softest.

○

Check the piston rod sliding surface for damage.

○

Apply fork oil to the piston rod sliding surface.

SUSPENSION 12-19

Front Fork

•

Drain the extra oil from the subtank oil hole [A].

•

With the cylinder unit in horizontal position, move [A] the

piston rod [B] by hand to inspect it if operating smoothly.

○

If the piston rod is not extend, remove the base valve

assembly and perform the air bleeding (pour the specified

amount fork oil and discharge an excess of oil).

•

Make sure about 16 mm (0.63 in.) [A] of push rod thread

is exposed from the lock nut [B].

•

Completely wipe of the fork oil from following parts.

Cylinder Unit [A]

Spring Collar [B] (KX250-R1)

Spring [C]

Spring Collar [D]

•

Insert above-mentioned parts into the fork.

•

Temporarily tighten the fork top plug [A] (subtank) using

the special tool.

Special Tool - Top Plug Wrench, 46 mm: 57001-1622 [B]

12-20 SUSPENSION

Front Fork

•

Clamp the axle holder with a vise.

○

Protect the axle holder with a rag when using a vise.

WARNING

Clamping the axle holder too tight can damage it

which will affect riding stability.

Do not clamp the axle holder too tight.

•

Compress the outer tube by hands and install the top plug

wrench [A] (special tool) between the axle holder bottom

and lock nut.

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

WARNING

Be careful of reaction force in spring and fix surely

so that special tool should not come off.

Do not place the fingers etc. while serving.

•

Insert the push rod [A] into the piston rod.

•

Replace the O-ring and gasket on the adjuster assembly

with new ones and apply specified fork oil to the O-ring.

•

Slowly turn the adjuster assembly [A] clockwise until re-

sistance is felt and check the clearance between the lock

nut [B] and adjuster assembly [A] to provide more than 1

mm (0.04 in.) [C].

•

Turn the lock nut [A] counterclockwise until it contacts with

the adjuster assembly [B].

•

With the lock nut held immovable using a wrench, tighten

the adjuster assembly to the specified torque.

Torque - Lock Nut/Adjuster Assembly: 29 N·m (3.0 kgf·m,

22 ft·lb)

•

With the outer tube compressed by hands, remove the

special tool.

SUSPENSION 12-21

Front Fork

•

Apply a non-permanent locking agent to the threads of

adjuster assembly.

•

Torque the adjuster assembly [A].

Torque - Adjuster Assembly: 58 N·m (6.0 kgf·m, 43 ft·lb)

•

Loosen and remove the fork top plug (subtank) form the

outer tube and slowly slide down the outer tube.

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

•

Pour [A] the specified amount of fork oil into the outer

tube.

Recommended Oil: KHL15-10 (KAYABA01) or

equivalent

Recommended Quantity:

KX250-R1

300 mL (10.14 US oz)

KX250R6F ∼

310 mL (10.48 US oz)

•

Raise the outer tube and temporarily tighten the fork top

plug (subtank).

Special Tool - Top Plug Wrench, 46 mm: 57001-1622

•

After installing the front fork, torque the top plug [A].

Special Tool - Top Plug Wrench, 46 mm: 57001-1622 [B]

The torque of fork top plug is specified to 29 N·m (3.0

kgf·m, 22 ft·lb), however, when you use the top plug

wrench (special tool) [A] reduce the torque to 90% of the

specified value [26 N·m (2.7 kgf·m, 20 ft·lb)] due to the

distance [B] between the center of the square hole, where

the torque wrench is fitted, and that of the octagonal hole

of the wrench.

This torque value [26 N·m (2.7 kgf·m, 20 ft·lb)] is appli-

cable when you use a torque wrench whose length gives

leverage of approximately 310 mm between the grip point

to the center of the coupling square.

12-22 SUSPENSION

Front Fork

Adjuster Assembly Inspection

•

Inspect the adjuster assembly [A] and push rod [B] for

damage.

If they are damaged, replace them with new ones.

•

Replace the gasket [C] and O-ring [D] on the adjuster as-

sembly with new ones.

Base Valve Assembly Inspection

•

Inspect the threads portion [A], bushing [B] and spring [C]

of base valve assembly [D] for damage.

If they are damaged, replace base valve assembly with

new one.

•

Replace the O-rings [E] with new ones.

Cylinder Unit Inspection

•

Inspect the piston rod [A] of cylinder unit [B] for scratches

or bending.

If it has scratches or is bent, replace cylinder unit with a

new one.

Inner Tube Inspection

•

Visually inspect the inner tube [A], repair any damage.

•

Nick or rust damage can sometimes be repaired by using

a wet-stone to remove sharp edges or raised areas which

cause seal damage.

If the damage is not repairable, replace the inner tube.

Since damage to the inner tube damages the oil seal,

replace the oil seal whenever the inner tube is repaired

or replaced.

•

Temporarily assemble the inner [A] and outer tubes [B],

and pump them down and up manually to check for

smooth operation.

CAUTION

If the inner tube is badly bent or creased, replace

it. Excessive bending, followed by subsequent

straightening, can weaken the inner tube.

SUSPENSION 12-23

Front Fork

Guide Bush Inspection

•

Visually inspect the guide bushes [A], and replace them if

necessary.

Dust Seal/Oil Seal Inspection

•

Inspect the dust seal [A] for any signs of deterioration or

damage.

Replace it if necessary.

•

Replace the oil seal [B] with a new one whenever it has

been removed.

Spring Tension

•

Since a spring becomes shorter as it weakens, check its

free length [A] to determine its condition.

If the spring of either fork leg is shorter than the service

limit, it must be replaced.

Fork Spring Free Length

Standard: 46 5 mm (18.31 in.)

Service Limit: 456 mm (17.95 in.)

12-24 SUSPENSION

Rear Suspension (Uni-Trak)

Rear Shock Absorber

The rear suspension system of this motorcycle is new Uni

-trak. It consists of a rear shock absorber, swing arm, tie-rod

and rocker arm.

To suit to various riding conditions, the spring preload of

the shock absorber can be adjusted or the spring can be

replaced with an optional one. Also the damping force can

be adjusted easily so changing oil viscosity unnecessary.

Rebound Damping Adjustment

•

Turn the rebound damping adjuster [A] on the rear shock

absorber lower end with the blade of a screwdriver until

youfeelaclick.

If the damper setting feels too soft or too s tiff, adjust it in

accordance with the following table:

Seated position: adjuster turned fully clockwise [A].

Rebound Damping A djuster Setting

Standard:

KX250-R1 9 clicks [B]

KX250R6F ∼ 10 clicks

Softer (Counterclockwise) [C]

Harder (Clockwise) [D]

*: Number of turns c ounterclockwise usable range-16

clicks or more.

CAUTION

Do not force the rebound and compression damp-

ing force adjusters beyond the fully seated position,

or the adjusting mechanism may be damaged.

NOTE

○

Adjustment of the rebound damping adjuster for the rear

suspension will slightly affect the compression damping

force. Always make any damping adjustments in small

steps and test their effects before using them in com-

petition.

SUSPENSION 12-25

Rear Suspension (Uni-Trak)

Compression Damping Adjustment

KX250-R1

•

Turn the compression damping adjuster [A] on the rear

shock absorber gas reservoir with a flat-blade screw-

driver.

KX250R6F ∼

There are two adjustments you can make to the rear

shock absorber gas reservoir.

•

To adjust the high speed compression damping, turn the

high speed compression damping adjuster [B] with a 17

mm wrench

•

To adjust the low speed compression damping, turn the

low speed compression damping adjuster [A] with a flat

head screwdriver.

If the damping feels too soft or too stiff, adjust it in accor-

dance with the following table.

High Speed Compression Damping Adjuster Setting

Standard:

KX250R6F ∼

11/4turnsout[B]

Seated position : adjuster turned fully clockwise [A].

Softer (Counterclockwise) [C]

Harder (Clockwise) [D]

*: Number of turns counterclockwise usable range-2

turns out.

Low Speed Compression Damping Adjuster Setting

Standard: 12clicks[B]

Seated position : adjuster turned fully clockwise [A].

Softer (Counterclockwise) [C]

Harder (Clockwise) [D]

*: Number of turns counterclockwise usable range-16

clicks or more.

CAUTION

Do not force the rebound and compression damp-

ing force adjusters beyond the fully seated position,

or the adjusting mechanism may be damaged.

NOTE

○

Adjustment of the rebound damping adjuster for the rear

suspension will slightly affect the compression damping

force. Always make any damping adjustments in small

steps and test their effects before using them in com-

petition.

12-26 SUSPENSION

Rear Suspension (Uni-Trak)

Spring Preload Adjustmen t

•

Remove:

Seat

Side Covers

Muffler

Rear Frame M ounting Bolts [A]

Rear Frame [B] with Air Cleaner Housing

•

Using the jack under the frame, raise the rear wheel off

the ground.

Special Tool - Jack: 57001-1238

•

Using the hook wrenches [A], loosen the locknut [B] on

the rear shock absorber.

Special Tool - Hook Wrench R37.5, R42: 57001-1101

•

Using the stem nut wrench [A], turn the adjusting nut [B]

as required. Turning the adjusting nut downward marks

the spring action harder and upward softer.

Special Tool - Steering Stem Nut Wrench: 57001-1100

Spring Preload Adjustment (Adjusting nut position at the

lower surface [A] from the center of the mounting hole)

Standard:

KX250-R1

120 mm (4.72 in.)

KX250R6F ∼

118 mm (4.65 in.)

Adjustable Range:

109 ∼ 129.5 mm (4.29 ∼ 5.10 in.)

•

Tighten the locknut securely.

•

After adjusting, move the spring up and down to m ake

sure that the spring is seated.

•

Install the parts removed.

•

Tighten the rear frame mounting bolts.

Torque - Rear Frame Mounting Bolts: 34 N·m (3.5 kgf·m 25

ft·lb)

SUSPENSION 12-27

Rear Suspension (Uni-Trak)

Spring Tension

•

Since the spring becomes shorter as it weakens, check

its free length [A] to determine its condition.

If the spring is shorter than the service limit, it must be

replaced.

Shock Absorber Spring Free Length

Standard: 260 mm (10.24 in.)

Service Limit: 255 m m (10.04 in.)

Rear Shock Absorb er Removal

•

Remove:

Seat

Side Covers

Muffler

Rear Frame with Air Cleaner Housing

•

Using the jack under the frame, raise the rear wheel off

the ground.

Special Tool - Jack: 57001-1238

CAUTION

When pulling out the mounting bolts, lift the rear

wheel slightly. Forcing or tapping on a bolt could

damage the bolt, sleeve, and bearing

•

Remove the rear shock absorber upper [A] and lower [B]

mounting bolts and nuts.

•

Remove the rear shock absorber [C].

Rear Shock Absorber Installation

•

Pack the rocker arm needle bearings with grease.

•

Tighten the following:

Torque - Rear Shock Absorber Mounting Nut (Upper): 39

N·m (4.0 k g f·m, 29 ft·lb)

Rear Shock Absorber Mounting Nut (Lower): 34

N·m (3.5 k g f·m, 24 ft·lb)

Tie-rod Mounting Nut: 83 N·m (8.5 kgf·m, 61 ft·lb)

Rear Frame Mounting Bolts: 34 N·m (3.5 kgf·m, 25

ft·lb)

Spring Replacement

In addition to the standard spring, heavy and light springs

are available. If the standard spring is improper for your

purpose, select a proper one according to the rider’s weight

or course conditions.

•

Remove:

Side Covers

Seat

Muffler

Rear Frame with Air Cleaner Housing

•

Remove the rear shock absorber.

•

Clean the threaded portion on the upper of the rear shock

absorber.

•

Hold the l ower of the rear shock absorber with a vise.

12-28 SUSPENSION

Rear Suspension (Uni-Trak)

•

Using the hook wrenches [C], loosen the locknut [B] and

turn the adjusting nut [A] all way up.

Special Tool - Hook Wrench R37.5, R42: 57001-1101

•

Remove the rear shock absorber from the vise.

•

Slide down t he rubber bumper [A].

•

Remove the spring guide [B] from the shock absorber and

lift off the spring [C].

•

Exchange the spring for an optional part. Install the spring

so that closed coil large diameter end [A] faces upward.

•

Install the spring guide.

•

Adjust the spring preload (see Spring Preload Adjust-

ment).

•

Install the rear shock absorber.

•

Install the parts removed.

Rear Shock Absorber Disassembly (Oil Change)

•

Refer to the Rear Shock Absorber Oil C hange in the Pe-

riodic Maintenance chapter.

Rear Shock Absorber Assembly

•

Refer to the Rear Shock Absorber Oil C hange in the Pe-

riodic Maintenance chapter.

Rear Shock Absorber Scrapping

WARNING

Since the r eservoir tank of the rear shock absorber

contains nitrogen gas, do not incinerate the reser-

voir tank without first releasing the gas or it may

explode.

•

Remove the shock absorber (see Rear Shock Absorber

Removal).

•

Remove the valve cap [A] and release the nitrogen gas

completely from the gas reservoir.

•

Remove the valve.

WARNING

Since the high pressure gas is dangerous, do not

point the valve toward your face or body.

SUSPENSION 12-29

Swingarm

Swingarm Removal

•

Remove:

Bolts [A]

Chain Guide Plate [B]

Chain Guide [C]

•

Place the jack [A] under the frame so that the rear wheel

is off the ground.

Special Tool - Jack: 57001-1238

•

Remove

Rear Wheel (see Wheels/Tires chapter)

Clamps [B]

Brake Pedal [C] (see Brakes chapter)

Caps [D]

Disc Protector [E]

•

Unscrew the rocker arm mounting nut [A] and pull out the

rocker arm bolt.

CAUTION

When pulling out the mounting bolts, lift the

swingarm slightly. Forcing or tapping on a bolt

could damage the bolt, sleeve, and bearing.

•

Unscrew the nut [A].

•

Pull out the swingarm pivot shaft, and remove the

swingarm [B].

•

Unscrew the screws [A]

•

Separate the chain slipper [B] from the swingarm.

12-30 SUSPENSION

Swingarm

Swingarm Installation

•

Apply plenty of grease to the inside of the needle bear-

ings, sleeves, and oil seals.

•

Tighten the following:

Torque - Swingarm Pivot Shaft Nut: 98 N·m (10.0 kgf·m, 72

ft·lb)

Rocker Arm Mounting Nut: 83 N·m (8.5 kgf·m, 61

ft·lb)

•

Refer to the Wheels/Tires, Final Drive, and Brakes chap-

ters for wheel installing.

Swingarm Bearing Removal

•

Remove:

Swingarm

Collars [A]

Grease Seals [B]

Sleeves [C]

Needle Bearings [D]

•

Remove the needle bearings [E] using the oil seal & bear-

ing remover.

Special Tool - Oil Seal & Bearing Remover: 57001-1058

Swingarm Bearing Installation

•

Replace the needle bearings and, grease seals with new

ones.

•

Apply plenty of grease to the grease seals, and needle

bearings [A].

NOTE

○

Install the needle bearings so that the manufacturer’s

marks face out.

○

Install the grease seals so that the deep groove side of

the rip faces in-ward.

Special Tool - Bearin g Driver Set: 57001-1129

•

Install the needle bearings [A], [B], and grease seals [C]

position as shown.

[D] 1.5 mm (0.059 in.)

[E] 1 mm (0.039 in.)

○

The installation procedure is the same as the counter

side.

Swingarm B earing, Slee ve Inspection

CAUTION

Do not remove the bearings for inspection. Re-

moval may damage them.

•

Inspect the needle bearings installed in the swingarm.

○

The rollers in a bearing normally wear very little, and wear

is difficult to measure. Instead of measuring, visually

inspect the bearing for abrasion, discoloration, or other

damage.

If the needle bearing, and sleeve show any sings of ab-

normal wear, discoloration, or damage, replace them as

aset.

SUSPENSION 12-31

Tie-rod, Rocker Arm

Tie-rod Removal

•

Using the jack under the frame, raise the rear wheel off

the ground.

Special Tool - Jack: 57001-1238

•

Unscrew the nut [A] and remove the guide roller [B].

CAUTION

When pulling out the mounting bolts, lift the rear

wheel slightly. Forcing or tapping on a bolt could

damage the bolt, sleeve, and bearing.

•

Remove the tie-rod rear mounting bolt [A].

•

Remove the tie-rod front mounting bolt [B], and then take

outthetie-rod[C].

Tie-rod Installation

•

Install the tie-rod [A] so that its mark [B] faces right side.

•

Apply plenty of grease to the inside of the oil seals.

•

Be sure seated the washers.

•

Tighten the tie-rod front and rear mounting nuts.

Torque - Tie-rod Mounting Nuts: 83 N·m (8.5 kgf·m, 61 ft·lb)

Rocker Arm Removal

•

Using the jack under the frame, raise the rear wheel off

the ground.

Special Tool - Jack: 57001-1238

CAUTION

When pulling out the mounting bolts, lift the rear

wheel slightly. Forcing or tapping on bolt could

damage the bolt, sleeve, and bearing.

•

Remove the rear shock absorber lower mounting bolt [A].

•

Remove the tie-rod rear mounting bolt [B].

•

Remove the caps [C].

12-32 SUSPENSION

Tie-rod, R ocker Arm

•

Remove the rocker arm pivot shaft [A].

•

Remove the rocker arm [B].

Rocker Arm Installation

•

Apply plenty of grease to the inside of the rocker arm,

needle bearings, oil seals and grease seals outside of the

sleeve.

•

Be sure seated the washers.

•

Tighten the following:

Torque - Rear Shock Absorber Mounting Nut (Lower): 34

N·m (3.5 k gf·m, 2 5 ft·lb)

Rocker Arm Pivot Nut: 83 N·m (8.5 kgf·m, 61 ft·lb)

Tie-rod Mounting Nuts: 83 N·m (8.5 kgf·m, 61 ft·lb)

Tie-rod and Rocker Arm Bearing Removal

•

Remove:

Tie-rod (see Tie-rod Removal)

Rocker Arm (see Rocker Arm Removal)

Washers [A]

Sleeves [B]

Oil Seal [C]

Grease Seals [D]

•

Remove the needle bearings [E], using the bearing re-

mover head and bearing remover shaft.

•

Remove the needle bearing [F], using the oil seal & bear-

ing remover.

Special Tools - Bearing Remover Head, 15 × 17: 57001

-1267

Bearing Remover Shaft,

9: 57001-1265

Oil Seal & Bearing Remover: 57001-1058

Tie-rod and Rocker Arm Bearing Installation

•

Replace the needle bearing, grease seals and oil s eals

with new ones.

•

Apply plenty of grease to the oil seal and needle bearings.

NOTE

○

Install the needle bearings so that the manufacturer’s

marks faces out.

○

Install the grease seals so that the deep groove side of

the rip out-ward.

SUSPENSION 12-33

Tie-rod, Rocker Arm

•

Install the needle bearings [A], [B], grease seals [C], and

oil seals [D] position as s hown.

○

The installation procedure is the same as the counter

side.

1. 1.5 mm (0.0591 in.)

2. 4.5 mm (0.1772 in.)

3. 1.0 mm (0.039 in.)

4. 4.25 mm (0.1673 in.)

5. 1.25 mm (0.0492 in.)

6. 1.25 mm (0.0492 in.)

7. 4.25 mm (0.1673 in.)

Needle Bearing Inspection

If there is any doubt as to the condition of either needle

bearing, replace the bearing and sleeve as a set.

12-34 SUSPENSION

Uni-Trak Maintenance

Uni-Trak Linkage Inspection

•

Refer to the Uni-Trak Linkage Inspection in the Periodic

Maintenance chapter.

Tie-rod and Rocker Arm Sleeve Wear

•

Pull out the sleeves [A] of the tie-rod and rocker arm.

•

Measure the outside diameter of the sleeve.

Ifthesleeveiswornpasttheservicelimit,replacethe

sleeve.

Sleeve Outside Diameter

Standard:

Tie-rod

19.987 ∼ 20.000 mm (0.7869 ∼ 0.7874 in.)

Rocker Arm:

Large

19.987 ∼ 20.000 mm (0.7869 ∼ 0.7874 in.)

Small 15.95 ∼ 16.00 mm (0.628 ∼ 0.630 in.)

Service Li mit:

Tie-rod

19.85 mm (0.781 in.)

Rocker Arm:

Large

19.85 mm (0.781 in.)

Small 15.91 mm (0.626 in.)

Tie-rod and Ro cker Arm Mountin g Bolt Ben d

A bent bolt causes vibration, poor handling, and instabil-

ity.

•

To measure the bolt runout, remove the bolt, place it in V

blocks, and set a dial gauge to the bolt at a point halfway

between the blocks. Turn [A] the bolt to measure the

runout. The amount of dial variation is the amount of

runout.

If runout exceeds the service limit, replace the bolt.

Bolt Runout

Standard: TIR 0.1 mm (0.004 in.) or less

Service Lim it: TIR 0.2 mm (0.008 in.)

STEERING 13-1

Steering

Table of Contents

Exploded View........................................................................................................................ 13-2

Special Tools .......................................................................................................................... 13-4

Steering .................................................................................................................................. 13-5

Steering Inspection ........................................................................................................... 13-5

Steering Adjustment.......................................................................................................... 13-5

Steering Stem, Stem Bearing Removal ............................................................................ 13-5

Steering Stem, Stem Bearing Installation ......................................................................... 13-7

Steering Maintenance ............................................................................................................. 13-9

Stem Bearing Lubrication.................................................................................................. 13-9

Stem Bearing Wear, Damage ........................................................................................... 13-9

Stem Warp ........................................................................................................................ 13-9

Handlebar............................................................................................................................... 13-10

Handlebar Removal (KX250-R1) ...................................................................................... 13-10

Handlebar Removal (KX250-R6F ∼) ................................................................................. 13-10

Handlebar Installation (KX250-R1) ................................................................................... 13-11

Handlebar Installation (KX250R6F ∼) ............................................................................... 13-12

13-2 STEERING

Exploded View

STEERING 13-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Handlebar Holder Bolts 25 2.5 18.0

2 Steering Stem Head Nut 98 10.0 72

3 Steering Stem Nut 4.9 0.5 43 in·lb T

4 Front Fork Clamp Bolts (Upper, Lower) 20 2.0 14.5 AL

5. Handlebar Holder(s) (Upper)

6. Handlebar

7. Handlebar Holders (Lower)

8. Steering Stem Head Bracket

9. Tapered Roller Bearing

10. Head Pipe

11. Tapered Roller Bearing

12. Steering Stem

13. Pad

AD: Apply adhesive cement.

AL: Tighten the clamp bolts alternately two times to ensure even tightening torque.

G: Apply grease.

O: Apply 2 Stroke Oil.

T: Tighten all snugly, then loosen, retighten to 4.9 N·m (0.5 kgf·m, 43 in·lb).

A: KX250-R1 Model

B: KX250R6F Model ∼

13-4 STEERING

Special Tools

Bearing Puller:

57001-135

Steering Stem Bearing Driver:

57001-137

Steering Stem Bearin g Driver Adapter, 34.5:

57001-1074

Head Pipe Outer Race Press Shaft:

57001-1075

Head Pipe Outer Race Driver, 51.5:

57001-1076

Head Pipe Outer Race Driver, 54.5:

57001-1077

Steering Stem N ut Wrench:

57001-1100

Head Pipe Outer Race Remov er ID > 37 mm:

57001-1107

Jack:

57001-1238

Bearing Puller:

57001-1575

STEERING 13-5

Steering

Steering Inspection

•

Refer to the Steering Inspection in the Periodic Mainte-

nance chapter.

Steering Adjustment

•

Refer to the Steering Adjustment in the Periodic Mainte-

nance chapter.

Steering Stem, Stem Bearing Removal

KX250-R1:

•

Remove:

Front Wheel (see Wheels/Tires chapter)

Number Plate [A]

Handlebar Holder Bolts [B]

Handlebar Holder (Upper) [C]

Handlebar [D] (see Handlebar Removal)

•

Pull out the breather hose [E].

KX250R6F ∼:

•

Remove:

Front Wheel (see Wheels/Tires chapter)

Number Plate [A]

Pad [B]

Handlebar Holder Bolts [C]

Handlebar Holder (Upper) [D]

Handlebar [E] (see Handlebar Removal)

•

Pull out the breather hose [F].

•

Loosen the steering stem head nut [A]

•

Remove:

Front Forks [B] (see Suspension chapter)

Brake Hose Clamp Bolt [C]

Brake Hose Clamp [D]

•

Remove the steering stem head nut and washer.

•

Remove the steering stem head [E].

•

Remove:

Front Fender Bolts [A]

Front Fender [B]

13-6 STEERING

Steering

•

Pushing up on the stem base [A], and remove the steering

stem nut [B], with the steering stem nut wrench [C], then

remove the steering s tem [D] and stem base.

Special Tool - Steering Stem Nut Wrench: 57001-1100

•

Take off the upper stem bearing inner race (tapered roller

bearing) [A].

•

Drive out the bearing outer races from the head pipe.

○

Remove the outer races pressed into the head pipe, using

the head pipe outer race remover [A], and hammer the

head pipe outer race remover to drive it out.

Special Tool - Head Pipe Outer Race Remover: 57001

-1107

NOTE

○

If either steering stem bearing is damaged, it is recom-

mended that both the upper and lower bearing (includ-

ing outer races) should be replaced with new ones.

•

Remove the lower stem bearing inner rase (tapered roller

bearing) [A] with its grease seal from the stem using bear-

ing pullers.

Special Tools - Bearing Puller: 57001-135

Bearing Puller: 57001-1575

○

Assemble the bearing puller (57001-1575).

○

Insert the each half-split base [A] under the bottom of

bearing inner race and connect the both bases by tight-

ening the bolts [B] and nuts [C].

○

Assemble the parts of the bearing puller (57001-135) as

shown in the figure.

Stud Bolts [D]

Arm [E]

Center Bolt [F]

Adapter [G]

○

Turn the center bolt by a wrench and pull the bearing inner

race.

NOTE

○

Tighten evenly two bases by the two bolts.

STEERING 13-7

Steering

Steering Stem, Stem Bearing Installation

•

Replace the bearing outer race with new ones.

○

Apply grease to the outer races, and drive them into the

head pipe at the same time using the head pipe outer race

press shaft [A] and the drivers.

Special Tools - Head Pipe Outer Race Press Shaft: 57001

-1075

Head Pipe Outer Race Driver,

51.5: 57001

-1076 [B]

Head Pipe Outer Race Driver,

54.5: 57001

-1077 [C]

•

Replace the lower inner races with new ones.

○

Apply grease to the lower tapered roller bearing [A], and

drive it onto the stem using the steering stem bearing

driver [B] and adapter [C].

Special Tools - Steering Stem Bearing Driver: 57001-137

Steering Stem Bearing Driver Adapter,

34.5: 57001-1074

•

Apply grease to the upper inner race, and install it in the

head pipe.

•

Install the stem through the head pipe and upper bearing,

and hand-tighten the nut while pushing up on the stem

base.

•

Install the stem head and washer, and tighten the stem

head nut lightly.

•

Settle the bearing in place as follows;

○

Tighten the stem nut to 39 N·m (4.0 kgf·m, 29 ft·lb) of

torque. (To tighten the steering s tem nut to the specified

torque, hook the wrench [A] on the s tem nut, and pull the

wrench at the hole by 22.2 kg force [B] i n the direction

shown.)

Special Tool - Steering Stem N ut Wrench: 57001-1100

○

Check that there is no play and the steering stem turns

smoothly without rattles. If not, the steering stem bearings

may be damaged.

○

Again back out the stem nut a fraction of a turn until it

turns lightly.

○

Turn the stem nut lightly clockwise until it just becomes

hard to turn. Do not overtighten, or the steering will be

too tight.

Torque - Steering Stem Nut: 4.9 N·m (0.5 kgf·m, 43 in·lb)

13-8 STEERING

Steering

•

Install the front fork (see the Suspension chapter).

NOTE

○

Tighten the fork upper clamp bolts first, next the stem

head nut, last the fork lower clamp bolt.

Torque - Steering Stem Head Nut: 98 N·m (10.0 kgf·m, 72

ft·lb)

Front Fork Clamp Bolts (Upper, Lower): 20 N·m

(2.0 kgf·m, 14.5 ft·lb)

NOTE

○

Tighten the two clamp bolts alternately two times to en-

sure even tightening torque.

•

Install the parts removed (see the appropriate chapter).

WARNING

Do not impede the handlebar turning by routing the

cables, wires and hoses improperly (see the Appen-

dix chapter).

•

Check and Adjust:

Steering

Front Brake

Clutch Cable

Throttle Cable

STEERING 13-9

Steering Maintenance

Stem Bearing Lubrication

•

Refer to the Stem Bearing Lubrication in the Periodic

Maintenance chapter.

Stem Bearing Wear, Damage

•

Using a high flash-point solvent, wash the upper and

lower tapered rollers in the cages, and wipe the upper

and lower outer races, which are press-fitted into the

frame head pipe, clean off grease and dirt.

•

Visually check the outer rase and the rollers.

Replace the bearing assembly if it show damage.

Stem Warp

•

Whenever the steering stem is removed, or if the steering

cannot be adjusted for smooth action, check the steering

stem for straightness.

If the steering stem shaft is bent [A], replace the steering

stem.

13-10 STEERING

Handlebar

Handlebar Remo val (KX250-R1)

•

Remove:

Clutch Holder [A] (see Clutch chapter)

Engine Stop Switch [B]

Clamp [C] (Discard)

Left Handlebar Grip [D]

•

Remove:

Throttle Grip A ssy [A] (see Fuel System chapter)

Master Cylinder [B] (see Brakes chapter)

•

Remove:

Number Plate [A]

Handlebar Holder Bolts [B]

Handlebar Holder (Upper) [C]

Handlebar [D]

Handlebar Removal (KX250-R6F

∼

)

•

Remove:

Clutch Holder [A] (see Clutch chapter)

Engine Stop Switch [B]

Clamp [C] (Discard)

Left Handlebar Grip [D]

Number Plate [E]

Pad [F]

•

Remove:

Throttle G rip Assy (see Fuel System chapter)

Master Cylinder (see Brakes chapter)

STEERING 13-11

Handlebar

•

Remove:

Handlebar Holder Bolts [A]

Handlebar Holders (Upper) [B]

Handlebar [C]

Handlebar Installation (KX250-R1)

•

Apply adhesive cement to the inside of the left handlebar

grip.

•

Install the left handlebar grip so that the arrow [A] on the

grip point to the punch mark [B] on the handlebar.

•

Install the clutch holder so that the parting line [A] of the

holder with punch mark [B] on the handlebar.

•

Apply grease to the throttle cable upper end and clutch

cable upper end.

•

Apply a 2 stroke oil to the throttle grip inner wall [A].

•

Install the throttle grip assy so that the grip [A] is in as far

as it will go.

○

Position the throttle grip assy so that the horizontal parting

line [B] of the throttle case with punch mark [C] on the

handlebar.

○

Install the master cylinder so that the vertical parting line

[D] of the front master cylinder clamps with punch mark

[E] on the handlebar.

13-12 STEERING

Handlebar

•

Install the handlebar [A] on the handlebar holder as

shown.

Same Length [B]

Bridge Bar [C]

•

Install the handlebar holder (see Steering Adjustment in

the Periodic Maintenance chapter).

○

Mount the handlebar holder [A] so that the marks [B] on

the clamp points toward rear.

○

First tighten the front clamp bolts [C], then, tighten the rear

clamp bolts [D]. After tightening the bolts, a clearance [E]

will be created behind the clamp.

Torque - Handlebar Holder Bolts: 25 N·m (2.5 kgf·m, 18

ft·lb)

•

Install the number plate.

Handlebar Installation (KX250R6F

∼

)

•

Apply adhesive cement to the inside of the left handlebar

grip.

•

Install the left handlebar grip and clutch holder as shown.

180 mm (7.09 in.) [A]

Frame Horizontal Line [B]

15° ∼ 25° [C]

20° ∼ 30° [D]

Arrow Mark [E]

Front [F]

•

Apply grease to the throttle cable upper end and clutch

cable upper end.

•

Apply a 2 stroke engine oil to the throttle grip inner wall

[A].

•

Install the throttle grip assembly so that the grip [A] is in

as far as it will go.

185 mm (7.28 in.) [B]

○

Position throttle grip assembly so that the horizontal part-

ing line [C] of the throttle case is parallel the frame hori-

zontal line [D] as shown.

•

Install the master cylinder so that the reserve tank cap

aline [E] to the frame horizontal line as shown.

STEERING 13-13

Handlebar

•

Install the handlebar [A] on the handlebar holder as

shown.

Same Length [B]

Bridge Bar [C]

Protrusion of Graduation [D]

•

Install the handlebar holders upeer. [A] with handlebar.

○

Tighten the front and rear bolts [B] of the handlebar

clamps equally.

If the handlebar clamps are correctly installed, there will

be same amount of gap [C] on the front and rear side of

the clamp after the bolts tightening.

Torque - Handlebar Holder Bolts: 25 N·m (2.5 kgf·m, 18

ft·lb)

•

Install:

Pad

Number Plate

FRAME 14-1

Frame

Table of Contents

Exploded View........................................................................................................................ 14-2

Frame ..................................................................................................................................... 14-4

Frame Inspection .............................................................................................................. 14-4

Rear Frame Removal........................................................................................................ 14-4

Rear Frame Installation..................................................................................................... 14-4

Seat ........................................................................................................................................ 14-5

Seat Removal ................................................................................................................... 14-5

Seat Installation ................................................................................................................ 14-5

Side Cover.............................................................................................................................. 14-6

Side Cover Removal ......................................................................................................... 14-6

Side Cover Installation ...................................................................................................... 14-6

Fender .................................................................................................................................... 14-7

Front Fender Removal ...................................................................................................... 14-7

Rear Fender Removal....................................................................................................... 14-7

Rear Fender Installation.................................................................................................... 14-7

Rear Flap Removal ........................................................................................................... 14-7

14-2 FRAME

Exploded View

FRAME 14-3

Exploded View

Torque

No. Fastener

N·m kgf·m ft·lb

Remarks

1 Rear Frame Mounting Bolt 34 3.5 25

2. Number Plate

3. Seat

4. Side Covers

5. Rear Frame

6. Frame

7. Rear Fender

8. Rear Flap

9. Front Fender

G: Apply grease.

R: Replacement Parts

14-4 FRAME

Frame

Frame Inspection

•

Refer to the Frame Inspection in the Periodic Mainte-

nance chapter.

Rear Frame Removal

•

Remove:

Seat (see Seat Removal)

Right & Left Side Cover (see Side Cover Removal)

Muffler (see E ngine Top End chapter)

Rear Fender (see Fender Removal)

Rear Flap (see Flap Removal)

•

Unscrew the air cleaner duct clamp screw [A].

•

Unscrew the rear frame mounting bolts [B].

•

Remove the rear frame [C] with air cleaner housing [D].

•

Remove:

Bolts [A]

Air Cleaner Housing [B]

Rear Frame I nstallation

•

Install the air cleaner housing.

•

Tighten the rear frame mounting bolts.

Torque - Rear Frame Mounting Bolts: 34 N·m (3.5 kgf·m, 25

ft·lb)

•

Install the removal parts.

FRAME 14-5

Seat

Seat Removal

•

Unscrew the bolts [A].

•

Pull [B] the seat [C] out from the back.

Seat Installation

•

Fit the hooks [A] of the seat under the flange collar [B] and

brackets [C].

14-6 FRAME

Side Cover

Side Cover Removal

•

Unscrew the bolts [A] and remove the side cover [B].

Side Cover Installation

•

Insert the tabs [A] of the cover into the air cleaner housing

[B].

FRAME 14-7

Fender

Front Fender Removal

•

Unscrew the bolts [A] and remove the front fender [B].

Rear Fender Removal

•

Remove:

Seat (see this chapter)

Side Covers (see this chapter)

•

Unscrew the bolts [A] and remove the rear fender [B].

Rear Fender Installation

•

Put [A] the nuts [B] (both sides) on the inside of rear fender

[C].

Rear Flap Removal

•

Unscrew the screws [A] and remove the rear flap [B].

ELECTRICAL SYSTEM 15-1

Electrical System

Table of Contents

Exploded View........................................................................................................................ 15-2

Wiring Diagram....................................................................................................................... 15-4

Specifications ......................................................................................................................... 15-5

Special Tools .......................................................................................................................... 15-6

Precautions............................................................................................................................. 15-7

Electrical Wiring...................................................................................................................... 15-8

Wiring Inspection .............................................................................................................. 15-8

Ignition Timing ........................................................................................................................ 15-9

Ignition Timing Adjustment................................................................................................ 15-9

Flywheel Magneto .................................................................................................................. 15-10

Flywheel Magneto Removal .............................................................................................. 15-10

Flywheel Magneto Installation ........................................................................................... 15-11

Flywheel Magneto Inspection ........................................................................................... 15-12

Regulator/Rectifier Removal ............................................................................................. 15-13

Regulator/Rectifier Inspection........................................................................................... 15-13

Ignition System ....................................................................................................................... 15-14

Safety Instructions ............................................................................................................ 15-14

Ignition Coil Removal ........................................................................................................ 15-14

Ignition Coil Inspection...................................................................................................... 15-14

Spark Plug Cleaning and Inspection................................................................................. 15-15

Spark Plug Gap Inspection ............................................................................................... 15-15

C.D.I U nit Removal ........................................................................................................... 15-15

C.D.I U nit Inspection ......................................................................................................... 15-15

Throttle Sensor Output/Input Voltage Check .................................................................... 15-20

Engine Stop Switch Electric Current Check...................................................................... 15-21

Crankshaft Sensor Inspection........................................................................................... 15-21

Crankshaft Sensor Air Gap Adjustment ............................................................................ 15-21

Throttle Sensor ....................................................................................................................... 15-22

Throttle Sensor Inspection ................................................................................................ 15-22

Throttle Sensor Position Adjustment................................................................................. 15-22

Fuel Cut Valve ........................................................................................................................ 15-23

Fuel Cut Valve Removal ................................................................................................... 15-23

Fuel Cut Valve Installation ................................................................................................ 15-23

Fuel Cut Valve Inspection ................................................................................................. 15-23

15-2 ELECTRICAL SYSTEM

Exploded View

ELECTRICAL SYSTEM 15-3

Exploded View

Torque

No Fastener

N·m kgf·m ft·lb

Remarks

1 Flywheel Nut 78 8.0 58

2 Stator Plate Mounting Screw 4.9 0.50 43 in·lb

3 Spark Plug 26 2.7 20

4 Magneto Cover Bolts 8.8 0.90 78 in·lb

5 Ignition Coil Mounting Bolts 8.8 0.90 78 in·lb

6 C.D.I Unit Mounting Bolts 8.8 0.90 78 in·lb

7. Magneto Cover

8. Flywheel Magneto

9. Stator

10. Ignition Coil

11. C.D.I Unit

12. Spark Plug Cap

13. Main Harness

14. Engine Stop Switch

15. Throttle Sensor

16. Fuel Cut Valve

R: Replacement Part

SS: Apply Silicon Sealant.

15-4 ELECTRICAL SYSTEM

Wiring Diagram

1. Magneto

2. Engine Stop Switch

3. Throttle Sensor

4. Fuel Cut Valve

5. Ignition Coil

6. Noise Suppressor

7. Spark Plug

8. C.D.I Unit

9. Crankshaft Sensor

ELECTRICAL SYSTEM 15-5

Specifications

Item Standard

Magneto

Crankshaft Sensor Air Gap: 0.45 ∼ 0.85 mm (0.018 ∼ 0.033 in.) KX250-R1,

R6F

0.65 ∼ 1.05 mm (0.026 ∼ 0.041 in.) KX250R7F

Crankshaft Sensor Resistance: approx. 240 Ω at 20°C (68°F)

Magneto Output Voltage: in the text

Magneto Coil Resistance: in the text

Regulator/Rectifier:

Internal Resistance in the text

Output Voltage 14.7 ±0.5 V

Ignition System

Ignition Timing:

(Disconnect the throttle sensor lead) 14° BTDC @7 090 r/min (rpm)

Ignition Coil:

3 Needle Arcing Distance 7 mm (0.26 in.) or more

Primary Winding Resistance 0.33 ±0.05 Ω (at 20°C)

Secondary Winding Resistance 9.0 ±1.35 kΩ (at 20°C)

Spark Plug:

Type NGK BR8ECMVX

Gap 0.7 ∼ 0.8 mm (0.026 ∼ 0.031 in.)

C.D.I. Unit in the text

Noise Suppressor Resistance 3.75 ∼ 6.25 Ω

Throttle Sensor

Input Voltage approx. 5 V

Output Voltage:

(when the throttle valve completely closed).

0.4 ∼ 0.6 V

(when the throttle fully opened). 3.5 ∼ 3.7 V

Fuel Cut Valve

Resistance 49.82 ∼ 56.18 at 20°C (68°F) Ω

Protrusion:

When battery is disconnected 19.4 ∼ 19.6 mm (0.76 ∼ 0.77 in.)

When battery is connected 21.3 ∼ 21.7 m m (0.84 ∼ 0.85 in.)

15-6 ELECTRICAL SYSTEM

Special Tools

Spark Plug Wrench, Hex 21:

57001-110

Flywheel Puller, M12 × 1.75:

57001-252

Hand Tester:

57001-1394

Peak Volt Adapter:

57001-1415

Needle Adapter Set:

57001-1457

Flywheel & Pulley Holder:

57001-1605

ELECTRICAL SYSTEM 15-7

Precautions

There are numbers of important precautions that are

musts when servicing electrical systems. Learn and ob-

serve all the rules below.

○

The electrical parts should never be struck sharply, as

with a hammer, or allowed to fall on a hard surface. Such

a shock to the parts can damage them.

○

Troubles may involve one or in some cases all items.

Never replace a defective part without determining what

CAUSED the failure. If the failure was caused by some

other item or items, they too must be repaired or replaced,

or the new replacement will soon fail again.

○

Make sure all connectors in the circuit are clean and tight,

and examine wires for signs of burning, fraying, etc. Poor

wires and bad connections will affect electrical system op-

eration.

○

Measure coil and winding resistance when the part is cold

(at room temperature).

○

Electrical Connectors

[A] C onnectors

[B] C onnectors

Safety Instructions:

WARNING

The ignition system produces extremely high volt-

age. Do not touch the spark plug, ignition coil, or

high tension lead while the engine is running, or

you could receive a severe electrical shock.

15-8 ELECTRICAL SYSTEM

Electrical Wiring

Wiring Inspection

•

Visually inspect the wiring for signs of burning, fraying,

etc.

If any wiring is poor, replace the damaged wiring.

•

Pull each connector [A] apart and inspect it for corrosion,

dirt, and damage.

If the connector is corroded or dirty, clean it carefully. If it

is damaged, replace it.

•

Check the wiring for continuity.

○

Use the wiring diagram to find the ends of the lead which

is suspected of being a problem.

○

Connect an ohmmeter between the ends of the leads.

○

Set the meter to the × 1 Ω range, and lead the meter.

If the meter does not read 0 Ω the lead is defective. Re-

place the lead or the wiring harness if necessary.

ELECTRICAL SYSTEM 15-9

Ignition Timing

Ignition Timing Adjustment

•

Remove the magneto cover.

•

Check to see if the center mark of the three marks [A]

on the magneto stator is aligned with the mark [B] on the

crankcase.

If the marks are not aligned, loosen the magneto stator

screws [C] and turn the magneto stator [D].

•

Tighten the screws securely.

Torque - Stator Plate Mounting Screws: 4.9 N·m (0.5 kgf·m,

43 in·lb)

•

Install the magneto cover.

Torque - Magneto Cover Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

The ignition timing can be adjusted for different power

band to suit to rider’s preference ability.

•

Remove the magneto cover.

•

Loosen the stator screws.

•

Adjust the timing by shifting the stator position within the

three lines [A].

B. Mark on Crankcase

NOTE

○

For best engine performance, it is very important to ad-

just the ignition timing within the adjustable range just

explained.

[A] Crankshaft Rotation

[B] Stator Movement

[C] Retard

[D] Advance

•

Tighten the stator screws securely (see Igniting Timing

Adjustment).

•

Install the magneto cover (see Ignition Timing Adjust-

ment).

Torque - Magneto Cover Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

•

Test ride the motorcycle and readjust the ignition timing if

necessary.

15-10 ELECTRICAL SYSTEM

Flywheel Magneto

Flywheel Magneto R emoval

•

Remove the magneto cover.

•

Hold the flywheel steady, w ith the flywheel holder [A], and

remove the flywheel nut [B].

Special Tool - Flywheel & Pulley Holder: 57001-1605

•

Remove the flywheel holder.

•

Screw the flywheel puller [A] into the flywheel by turning

it counterclockwise ( left-hand thread).

•

Remove the flywheel from the crankshaft by turning in the

puller center bolt and tapping the head of the bolt lightly

with a hammer, while holding the puller body steady.

There is a woodruff key in the crankshaft tapered portion.

Special Tool - Flywheel Puller, M12 × 1.75: 57001-252

CAUTION

Never strike the grab bar or the flywheel itself. Strik-

ing the bar can bend it. If the flywheel is strike, the

magnets may lose their magnetism.

•

Unscrew the mounting screws [A], and remove the s tator

plate [B] and the wiring grommet [C].

•

Remove the band.

•

Remove the left radiator shroud.

•

Push down the stopper [A] and remove the magneto l ead

connector [B] from the frame.

•

Disconnect the magneto lead connector.

ELECTRICAL SYSTEM 15-11

Flywheel Magneto

Flywheel Magneto Installation

•

Using a high flash-point solvent, clean off any oil or dirt

that may be on the crankshaft taper [A] or in the hole [B]

in the flywheel. Dry them with a clean cloth.

•

Fit the woodruff key [A] securely in the slot in the crank-

shaft before installing the stator plate.

•

Apply silicone sealant around the circumference of the

wiring grommet.

•

Set the stator wiring grommet [A] securely in the notch [B]

in the left crankshaft half, and route the wires according

to the Cable, Harness, Hose Routing section in the Ap-

pendix c hapter.

•

Install the stator plate and tighten it.

Torque - Stator Plate Mounting Screws: 4.9 N·m (0.50

kgf·m, 43 in·lb)

•

Holding the flywheel steady, with the flywheel holder, and

tighten the flywheel nut.

Special Tool - Flywheel & Pulley Holder: 57001-1605

Torque - Flywheel Nut: 78 N·m (8.0 kgf·m, 58 ft·lb)

•

Measure the crankshaft sensor air gap [A] (Clearance be-

tween the flywheel and the crankshaft sensor [B] core.)

Crankshaft Sensor Air Gap

Standard: 0.45 ∼ 0.85 mm (0.018 ∼ 0.033 in.) KX250-R1,

R6F

0.65 ∼ 1.05 mm (0.026 ∼ 0.041 in.) KX250R7F

If the gap is incorrect, adjust it (see this chapter).

•

Replace the gasket with a new one.

•

Connect the magneto lead connector to the main harness.

15-12 ELECTRICAL SYSTEM

Flywheel Magneto

Flywheel Magneto In spection

•

There are three types of magneto problems: short, open

(wire burned out), or loss in flywheel magnetism. A short

or open in one of the coil wires will result in either a low

output, or no output at all. A loss in flywheel magnetism,

which may be caused by dropping or hitting the flywheel

by leaving it near an electromagnetic field, or just by ag-

ing, will result in low output.

•

Check the magneto output voltage, do the following pro-

cedures.

○

Push down the stopper [A] and remove the magneto l ead

connector [B] from the frame.

○

Connect the hand tester [A] to the connector [B] as shown

in the table 1 using the needle adapter set [C]

○

Start the engine.

○

Run it at the rpm given in the table 1.

○

Note the voltage readings (total 2 measurements).

Special Tool - Needle Adapter Set: 57001-1457

Table 1 Magneto Output Voltage

Connections

Tes ter

Range

Tes ter (+ ) t o Te st er (– ) t o

Reading

@4 000 rpm

250 V AC

White lead Red lead 59 V or more

50 V AC

Yellow/W hite

lead

Yellow lead 16 V or more

If the output voltage shows the value in the table, the mag-

neto operates properly.

If the output voltage shows a much higher than the value

in the table, the regulator/rectifier is damaged. A much

lower reading than that given in the table indicates that

the magneto is defective.

•

To check the stator coil resistance as follows.

○

Stop the engine.

○

Disconnect the auxiliary leads.

○

Connect the hand tester as shown in the table 2.

○

Note the readings (total 2 measurement).

Connections

Tes ter

Range

Tes t e r ( +) t o Tes ter (–) to

Reading

White lead Red lead 10 ∼ 30 Ω

×1Ω

Yellow/White lead Yellow lead 1 ∼ 4 Ω

ELECTRICAL SYSTEM 15-13

Flywheel Magneto

If there is more resistance than shown in the table, or no

hand tester reading (infinity) the stator has an open lead

and must be replaced. Much less than this resistance

means the stator is shorted, and must be replaced.

•

Using the highest resistance range of the hand tester,

measure the resistance between each leads and chas-

sis ground.

Any hand tester reading less than infinity (∞) indicates a

short, necessitating stator replacement.

If the stator coils have normal resistance, but the voltage

check showed the magneto to be defective; then the rotor

magnets have probably weakened, and the rotor must be

replaced.

Special Tool - Hand Tester: 57001-1394

Regulator/Rectifier Removal

○

Regulator/rectifier is bult in the C.D.I unit (see C.D.I. Unit

Removal in this chapter).

Regulator/Rectifier Inspection

•

Remove the C.D.I. unit.

•

Regulator/Rectifier is bult in the C.D.I. unit.

•

Set the hand tester × 100 Ω range, measure the internal

resistance in both directions between the terminals.

Special Tool - Hand Tester: 57001-1394

If the reading is not specified value, replace the C.D.I. unit.

Ter m in al

Tester (+) Lead Tester (–) Leaed

Standard Value

Y/W

7.5 ∼ 30 Ω

Y BK

7.5 ∼ 30 Ω

Y/W

∞

BK Y

∞

R/W Y/W 8.5 ∼ 34 Ω

R/W

8.5 ∼ 34 Ω

Y/W R/W

∞

R/W

∞

CAUTION

Use only Hand Tester 57001-1394 for this test. An

ohmmeter other than the Hand Tester may show

different readings. If a megger or a meter with a

large-capacity battery is used, the r egu lator will be

damaged.

15-14 ELECTRICAL SYSTEM

Ignition System

Safety Instructions

WARNING

The ignition system produces extremely high volt-

age. Do not touch the spark plug, ignition coil, or

high tension lead while the engine is running, or

you could receive a severe electrical shock.

Ignition Coil Removal

•

Remove:

Seat

Radiator Shrouds

Fuel Tank

•

Disconnect the ignition coil primary lead [A].

•

Pull the plug cap [B] off the spark plug.

•

Unscrew the mounting bolts [C], and remove the ignition

coil [D].

Ignition Coil Inspection

Measuring arcing distance

The most accurate test for determining the condition of

the ignition coil is made by measuring arcing distance using

the coil tester for the 3-needle method.

•

Remove the ignition coil.

•

Connect the ignition coil (with the spark plug cap left in-

stalled on the high tension lead) [A] to the tester [B], and

measure the arcing distance.

WARNING

To avoid extremely high voltage shocks, do not

touch the ignition coil or lead.

If the distance reading is less than the specified value, the

ignition coil or spark plug cap is defective.

3 N eedle Arcing Distance

Standard: 7 mm (0.26 in.) or more

•

To determine which part is defective, measure the arcing

distance again with the spark plug cap removed from the

ignition coil lead.

If the arcing distance i s subnormal as before, the trouble

is with the ignition coil itself. If the arcing distance is now

normal, the trouble is with the spark plug cap.

ELECTRICAL SYSTEM 15-15

Ignition System

Measuring Coil Resistance

If the arcing tester is not available, the coil can be

checked for a broken or badly shorted winding with an

ohmmeter. However, an ohmmeter cannot detect layer

shorts and shorts resulting from insulation breakdown

under high voltage.

•

Remove the i gnition coil.

•

Measure the primary winding resistance [A].

○

Connect an ohmmeter between the coil terminals.

○

Set the meter to the × 1 Ω range, and read the meter.

•

Measure the secondary winding resistance [B].

○

Pull the spark plug cap off the lead.

○

Connect an ohmmeter between the high tension lead and

the ground lead terminal.

○

Set the meter to the × 1 kΩ range, and read the meter.

If the meter does not read as specified, replace the coil.

If the meter reads as specified, the ignition coil windings

are probably good. However, if the ignition system still

does not perform as it should after all other components

have been checked, test replace the coil with one known

to be good.

Ignition Coil Winding Resistance

Primary windings: 0.33 ±0.05 Ω (at 20°C)

Secondary windings: 9.0 ±1.35 kΩ (a t 20°C)

•

Check the high tension lead for visible damage.

If the high tension lead is damaged, replace the coil.

Spark Plug Cleaning and Inspection

•

Refer to the Spark Plug Cleaning and Inspection in Peri-

odic Maintenance c hapter.

Spark Plug G ap Inspection

•

Refer to the Spark Plug Gap Inspection in Periodic Main-

tenance chapter.

C.D.I Unit Removal

•

Remove the number plate.

•

Disconnect the main harness connector [A].

•

Unscrew the mounting bolt [B] and remove the C.D.I Unit

[C].

C.D.I Unit Inspection

CAUTION

When inspecting the C.D.I. unit observe the follow-

ing to avoid damage to the C.D.I. unit.

Do not disconnect the C.D.I. unit while the engine is

running.

This may damage the C.D.I. unit.

15-16 ELECTRICAL SYSTEM

Ignition System

Ignition Coil Primary Peak Voltage Check

•

Disconnect the spark plug cap from mounting the spark

plug.

•

Connect the good spark plug [A] to the spark plug cap,

then touch the engine with the spark plug.

NOTE

○

Measure the voltage with each lead connected cor-

rectly. The correct value may not be obtained if

disconnected.

○

Maintain the correct value of compression pressure for

the cylinder. (Be sure to measure the voltage with the

spark plug install to the cylinder head.)

○

The correct value may not be obtained if disconnected.

•

Connect the peak voltage adapter [B] between the termi-

nal of primary lead (orange) and ground connection of the

unit with the lead of the ignition coil [C] connected.

Special To o ls - Peak Voltage Adapter: 570 01-1 4 15

Type: KEK-54-9-B

Connection

Adapter Positiv e → GroundLead[D]

Adapter Negative →Orange Lead [E]

C.D.I Unit [F]

Needle Adapter [G]

Special Tool - Needle Adapter Set: 57001-1457

•

Shift the gear to the neutral position, then free the engine

stop switch.

•

Crank the engine by kicking the pedal several times to

measure the peak voltage of the primary ignition coil.

Peak Voltage: 150 V or above

WARNING

Do not touch the metal portion of the probe in case

of measuring the voltage, or you may receive a se-

rious electric shock.

If the voltage is less than the specified value, see the next

page.

ELECTRICAL SYSTEM 15-17

Ignition System

15-18 ELECTRICAL SYSTEM

Ignition System

Crankshaft Sensor Peak Voltage Check

•

To check the peak voltage, do the following procedures.

○

Disconnect the connector of the magneto lead connector

from the m ain harness.

NOTE

○

Measure the voltage with each lead connected cor-

rectly. The correct value may not be obtained if

disconnected.

○

Maintain the correct value of compression pressure for

the cylinder (Be sure to measure the voltage with the

spark plug installed to the cylinder head).

○

The correct value may not be obtained if disconnected.

○

Connect the peak voltage adapter [A] of the tester to the

terminals of the magneto lead connector [B].

Special To o ls - Peak Voltage Adapter: 570 01-1 4 15

Type: KEK-54-9-B

Connection

Adapter Positive → Green/White Lead [C]

Adapter Negative → White/Yellow Lead [D]

○

Crank the engine by kicking the pedal several times to

measure the peak voltage of the crankshaft sensor.

Peak Voltage: 1.6 V or above

WARNING

Do not touch the metal portion of the probe in case

of measuring the voltage, or you may receive a se-

rious electric shock.

If the voltage is less than the specified, check the crank-

shaft sensor.

ELECTRICAL SYSTEM 15-19

Ignition System

Exciter Coil Peak Voltage Check

•

Disconnect the connector of the magneto lead connector

from the m ain harness.

•

To check the peak voltage, do the following procedures.

NOTE

○

Measure the voltage with each lead connected cor-

rectly. The correct value may not be obtained if

disconnected.

○

Maintain the correct value of compression pressure for

the cylinder (Be sure to measure the voltage with the

spark plug installed to the cylinder head).

○

The correct value may not be obtained if disconnected.

○

Connect the peak voltage adapter [A] of the tester to the

terminals of the magneto lead connector [B].

Special Tools - Peak Voltage Adapter: 57001-1415

Type: KEK-54-9-B

Connection

Adapter Positive → White Lead [C]

Adapter Negative → RedLead[D]

○

Crank the engine by kicking the pedal several times to

measure the peak voltage of the exciter coil.

Peak Vo ltag e : 16 V or abo v e

If the voltage is less than the specified, check the exciter

coil.

Fuel Cut Valve Operation Check

•

Disconnect the carburetor lead connector [A].

•

Set the tester to the DC25V range, and connect it to the

carburetor lead of the main harness side.

Connections

Tester Positive → Red/White Lead [B]

Tester Negative → BrownLead[C]

•

Start the engine.

•

Run it at the rpm given below.

Fuel Cut Valve Operate Revolutions

Standard: 8 100 rpm

•

Read the tester, running the engine at the specified revo-

lution.

Fuel Cut Valve Operation Voltage:

When engine is specified revolutions or above: DC 12 V

When en gine is less than spe cified revolutions: 0 V

If the tester does not read as specified, check the mag-

neto.

If the m agneto has normal functions, replace the C.D.I.

Unit.

15-20 ELECTRICAL SYSTEM

Ignition System

Throttle Sensor Output/Input Voltage Check

NOTE

○

If the variable rheostat is available, refer to throttle sen-

sor inspection.

•

Remove the carburetor lead connector.

•

Connect the needle adapter set [A] to the carburetor lead

connector [B].

Special Tool - Needle Adapter Set: 57001-1457

•

Set the tester [C] to the DC 10 V range, and connect it to

the needle adapter set.

Hand Tester (+) → Red/Green Lead

Hand Tester (–) → Black/Green Lead

•

Start the engine.

•

Check the sensor input voltage with the engine running.

Throttle Sensor Input Voltage

Standard:

approx. 5 V

If it is not within the s pecified voltage range, check the

magneto output voltage. If it has normal functions, re-

place the C.D.I. Unit.

•

To check the output voltage, do the following procedures.

○

Connect the needle adapter set [A] to the carburetor lead

connector [B].

Special Tool - Needle Adapter Set: 57001-1457

○

Connect the hand tester [C] to the needle adapter set.

○

Connect the hand tester as follows.

Hand Tester (+) → White/Black Lead

Hand Tester (–) → Black/Green Lead

○

Remove the spark plug.

○

Crank the engine by kicking the pedal several times to

measure the throttle sensor output voltage with the throt-

tle valve completely closed.

Throttle Sensor Output Voltage

Standard:

0.4 ∼ 0.6 V (when throttle valve is

completel y closed.)

If it is not within the specified voltage range, adjust the

throttle sensor position (see Throttle Sensor Position Ad-

justment).

If it is within specified voltage, go to next test.

○

Crank the engine by kicking the pedal several times to

measure the throttle sensor output voltage with the throt-

tle fully opened.

Throttle Sensor Output Voltage (when the throttle fully

opened)

Standard:

3.5 ∼ 3.7 V

If it is not within the specified voltage, replace the throttle

sensor.

ELECTRICAL SYSTEM 15-21

Ignition System

Engine Stop Switch Electric Current Ch eck

•

Disconnect the engine stop switch lead.

•

Start the engine.

•

Ground the stop switch lead of the main harness side

while the engine is running.

If does not stop the engine, replace the C.D.I Unit.

Crankshaft Sensor Inspection

•

Remove:

Magneto Lead Connector (see Flywheel Magneto In-

spection).

•

Set the hand tester [A] to the × 100 Ω range and connect

it to the Green/White [B] and White/Yellow [C] Leads in

the connector.

Special Tool - Hand Tester: 57001-1394

If there is more resistance than the specified value, the

coil has an open lead and must be replaced. Much less

than this resistance means the coil is shorted, and must

be replaced.

Crankshaft Sensor Resistance: approx. 240 Ω at 20°C

(68°F)

•

Using the highest resistance range of the tester, measure

the resistance between the c rankshaft sensor leads and

chassis ground.

Any tester reading less than infinity (∞) i ndicates a short,

necessities replacement of the crankshaft sensor assem-

bly.

Crankshaft Sensor Air Gap Adjustment

•

Loosen the crankshaft sensor screws [A].

•

Insert a thickness gauge [B] between the crankshaft sen-

sor core and the timing plate.

Thickness Gauge: 0.65 mm (0.026 in.) KX250-R1, R6F

0.85 mm (0.033 in.) KX250R7F

•

While pressing the crankshaft sensor toward the magneto

flywheel, tighten the coil screws and remove the thickness

gauge.

•

Check the air gap (see Flywheel Magneto Installation).

If the air gap is not within the specified range, readjust the

gap.

15-22 ELECTRICAL SYSTEM

Throttle Sensor

Throttle Sensor Inspection

NOTE

○

If the variable rheostat is not available, refer to throttle

sensor output/input voltage check in the C.D.I Unit in-

spection.

○

When inspecting the throttle sensor the throttle valve of

the carburetor shall be completely closed and remain

the throttle cable connected.

•

Remove the carburetor (see Fuel System chapter).

•

Connect the carburetor lead connector [A] with the battery

[B], variable rheostat [C] and hand testers [D] as shown.

Variable Rheostat (+) → R/G Lead Terminal [E]

Hand Tester (+) → W/BK Lead terminal [F]

Hand Tester (–) → BK/G Lead terminal [G]

•

Check the sensor input voltage.

Throttle Sensor Input Voltage

Standard: around 5 V

•

Check the sensor output voltage with the throttle valve is

completely closed.

Throttle Sensor Output Voltage

Standard: 0.4 ∼ 0.6 V (when the throttle valve

completel y closed.)

If it is not within the specified voltage, adjust the throt-

tle sensor position (see Throttle Sensor Position Adjust-

ment).

If it is within specified voltage, go to next test.

•

Check the sensor output voltage with the throttle fully

opened.

Throttle sensor Output Voltage

Standard: 3.5 ∼ 3.7 V (When throttle fully opened.)

If it is not within the specified voltage, replace the sensor.

Throttle Sensor Position Adjustment

•

Remove the carburetor.

•

Check the throttle v alve is completely closed.

•

Loosen the throttle sensor mounting bolt [A].

•

Connect the carburetor lead connector with the battery,

variable rheostat and handtesters in the same manner as

specified in the throttle sensor Inspection.

•

Adjust the position of the sensor until the output voltage

is within the specified voltage range.

Throttle Sensor Output Voltage

Standard: 0.4 ∼ 0.6 V (when throttle valve is

completel y closed.)

•

If it is not within the specified voltage range, replace the

sensor.

ELECTRICAL SYSTEM 15-23

Fuel Cut Valve

Fuel Cut Valve Removal

WARNING

Gasoline is extremely flammable and can be ex-

plosive under certain conditions. Turn the ignition

switch OFF. Do not smoke. Make sure the area is

well-ventilated and free from any source of flame

or sparks; this includes any appliance with a pilot

light.

•

Disconnect the carburetor lead connector.

•

Remove the carburetor.

•

Drain the fuel from the float bowl removing the drain plug.

After draining, install the drain plug securely.

•

Loosen the fuel cut valve [A] and remove it.

Fuel Cut Valve Installation

•

Installation is reverse of removal.

Fuel Cut Valve Inspection

•

Remove the fuel cut valve [A].

•

Connect and disconnect one 12 V battery [B] to the car-

buretor lead connector as shown. The valve rod moves.

If the protrusion exceeds the standard (too long or too

short), the valve is defective and must be replaced.

Testing Fuel Cut Valve

Standard Protrusion

When battery is disconnected [C] 19.4 ∼ 19.6 mm

(0.76 ∼ 0.77 in.)

When battery is connected [D] 21.3 ∼ 21.7 mm (0 .84 ∼

0.85 in.)

APPENDIX 16-1

Appendix

Table of Contents

Troubleshooting Guide ........................................................................................................... 16-2

Cable, Wire and Hose Routing ............................................................................................... 16-6

16-2 APPENDIX

Troubleshooting Guide

NOTE

○

This is not an exhaustive list, giving every

possible cause for each problem listed. It

is meant simply as a rough guide to assist

the troubleshooting for some of the more

common difficulties.

Engine Doesn’t Start, Starting

Difficulty

Engine won’t turn over

Cylinder, piston seizure

Crankshaft seizure

Connecting rod small end seizure

Connecting rod big end s eizure

Transmission gear or bearing seizure

Kick shaft return spring broken

Kick ratchet gear not engaging

No fuel flow

No fuel in tank

Fuel tap turned off

Tank cap air vent obstructed

Fuel tap clogged

Fuel line clogged

Float valve clogged

Fuel cut valve left close

Engine flooded

Float level too high

Float valve worn or stuck open

Starting technique faulty

(when flooded, kick with the throttle fully

open to

allow more air to reach the engine.)

No spark; spark weak

Spark plug dirty, broken, or maladjusted

Spark plug cap or high tension wiring trou-

ble

Spark plug cap not in good contact

Spark plug incorrect

C.D.I Unit trouble

Ignition coil trouble

Ignition coil resistor open

Flywheel magneto damaged

Wiring shorted or open

Fuel/air mixture incorrect

Idle adjusting screw maladjusted

Slow jet or air passage clogged

Air cleaner clogged, poorly sealed, or miss-

ing

Starter jet clogged

Compression Low

Spark plug loose

Cylinder head not sufficiently tightened

down

Cylinder, piston worn

Piston ring bad (worn, weak, broken, or

sticking)

Piston ring/groove clearance excessive

Cylinder head gasket damaged

Cylinder head warped

Cylinder base gasket damaged

Read valve damaged

Cylinder nut loose

Poor Running at Low Speed

Spark weak

Spark plug dirty, broken, or maladjusted

Spark plug cap or high tension wiring trou-

ble

Spark plug cap shorted or not in good con-

tact

Spark plug incorrect

C.D.I Unit trouble

Ignition coil trouble

Flywheel magneto damaged

Ignition coil lead or C.D.I Unit lead not in

good contact

Fuel/air mixture incorrect

Idle adjusting screw maladjusted

Slow jet or air passage clogged

Air c leaner clogged, poorly sealed, or miss-

ing

Starter plunger stuck open

Float level too high or too low

Fuel tank air vent obstructed

Fuel cut valve won’t fully open

Carburetor holder loose

Air cleaner duct loose

Compression Low

Spark plug loose

Cylinder head not sufficiently tightened

down

Cylinder, piston w orn

Piston ring bad (worn, weak, broken, or

sticking)

Piston ring/groove clearance excessive

Cylinder head gasket damaged

Cylinder head warped

Cylinder base gasket damaged

Reed valve damaged

Cylinder nut loose

Kips ports stuck open

KIPS exhaust valve stuck open (valve

seizure, or carbon accumulation)

KIPS exhaust valves assembled incorrectly

Exhaust advancer spring damaged

Exhaust valve operating rod seizure

Rod (for KIPS) seized in cylinder

Other

C.D.I Unit trouble

Transmission oil viscosity too high

Brake dragging

APPENDIX 16-3

Troubleshooting Guide

Poor Running or No Power at High

Speed

Firing incorrect

Spark plug dirty, damaged, or maladjusted

Spark plug cap or high tension wiring dam-

aged

Spark plug cap shorted or not in good con-

tact

Spark plug incorrect

C.D.I Unit trouble

Ignition coil trouble

Flywheel magneto damaged

Ignition coil lead or C.D.I Unit lead not in

good contact

Fuel/air mixture incorrect

Main jet clogged or wrong size

Jet needle or needle j et worn

Jet needle clip in wrong position

Float level too high or too low

Fuel cut valve won’t fully open

Air jet or air passage clogged

Air cleaner clogged, poorly sealed, or miss-

ing

Starter p lunger stuck open

Fuel to carburetor insufficient

Water or foreign matter in fuel

Fuel tank air vent obstructed

Carburetor holder loose

Air cleaner duct loose

Fuel tap clogged

Fuel line clogged

Compression low

Spark plug loose

Cylinder head not sufficiently tightened

down

Cylinder, piston worn

Piston ring bad (worn, weak, broken, or

sticking)

Piston ring/and clearance excessive

Cylinder head gasket damaged

Cylinder head warped

Cylinder base gasket damaged

Reed valve damaged

Cylinder nut loose

Engine rpm will not rise properly

Starter p lunger stuck open

Float level too high or too low

Main jet clogged

Throttle valve does not fully open

Air cleaner clogged

Muffler clogged

Water or foreign matter in fuel

Cylinder exhaust port clogged

Brake dragging

Clutch slipping

Overheating

Transmission oil level too high

Transmission oil viscosity too high

Crankshaft bearing worn or damaged

KIPS ports stuck closed

KIPS exhaust valves stuck closed (valve

seizure, or carbon accumulation)

KIPS exhaust valves assembled incorrectly

KIPS ports clogged (carbon accumulation)

Rod (for KIPS) seized in cylinder

Knocking

Carbon built up in combustion chamber

Fuel poor quality or i ncorrect

Spark plug incorrect

C.D.I Unit trouble

Overheating

Firing incorrect

Spark plug dirty, broken, or maladjusted

Spark plug incorrect

C.D.I Unit trouble

Fuel/air mixture incorrect

Main jet clogged or wrong size

Fuel level in c arburetor float bowl too low

Fuel cut valve won’t fully open

Carburetor holder loose

Air cleaner poorly sealed, or missing

Air cleaner duct poorly sealed

Air cleaner clogged

Compression high

Carbon built up in combustion chamber

Engine load faulty

Brake dragging

Clutch slipping

Transmission oil level too high

Transmission oil viscosity too high

Lubrication inadequate

Transmission oil level too low

Transmission oil poor quality or incorrect

Coolant incorrect

Coolant level too low

Coolant deteriorated

Cooling system component incorrect

Radiator clogged

Radiator cap trouble

Water pump not rotating

Clutch Operation Faulty

Clutch slipping

No clutch lever play

Clutch cable m aladjusted

Clutch inner cable catching

Friction plate worn or warped

Steel plate worn or warped

Clutch spring broken or weak

Clutch release mechanism trouble

Clutch hub or housing unevenly worn

Clutch not disengaging properly

Clutch lever play excessive

16-4 APPENDIX

Troubleshooting Guide

Clutch plate warped or too rough

Clutch spring tension uneven

Transmission oil deteriorated

Transmission v iscosity too high

Transmission oil level too high

Clutch housing frozen on drive shaft

Clutch release mechanism trouble

Gear Shifting Faulty

Doesn’t into gear; shift pedal doesn’t

return

Clutch not disengaging

Shift fork bent or seized

Gear stuck on the shaft

Gear positioning lever binding

Shift return spring weak or broken

Shift return spring pin loose

Shift mechanism arm spring broken

Shift mechanism arm broken

Shift drum broken

Jumps out of gear

Shift fork worn

Gear groove worn

Gear dogs and/or dog holes worn

Shift drum groove worn

Gear positioning lever spring weak or bro-

ken

Shift fork guide pin worn

Drive shaft, output shaft, and/or gear

splines worn

Overshifts

Gear positioning lever spring weak or bro-

ken

Shift mechanism arm spring broken

Abnormal Engine Noise

Knocking

C.D.I Unit trouble

Carbon built up in combustion chamber

Fuel poor quality or incorrect

Spark plug incorrect

Overheating

Piston slap

Cylinder/piston clearance excessive

Cylinder, piston worn

Connecting rod bent

Piston pin, piston pin hole worn

Other noise

Connecting rod small end clearance exces-

sive

Connecting rod big end clearance exces-

sive

Piston ring worn, broken or stuck

Piston seizure or damaged

Cylinder head gasket leaking

Exhaust pipe leaking at cylinder head con-

nection

Crankshaft runout excessive

Engine mounts loose

Crankshaft bearing worn

Primary gear worn or chipped

Abnormal Drive Train Noise

Clutch noise

Clutch housing/friction plate clearance ex-

cessive

Clutch housing gear/primary gear backlash

excessive

Metal chip jammed in clutch housing gear

teeth

Transmission noise

Crankcase bearing worn or damaged

Transmission gear worn or chipped

Metal chip jammed in gear teeth

Transmission oil insufficient or too thin

Kick ratchet gear not properly disengaging

from kick gear

Output shaft idle gear worn or chipped

Drive chain noise

Drive chain adjusted improperly

Chain worn

Rear and/or engine sprocket(s) worn

Chain lubrication insufficient

Rear wheel misaligned

Abnormal Frame Noise

Front fork noise

Oil insufficient or too thin

Spring weak or broken

Front fork air pressure high

Rear shock absorber noise

Shock absorber damaged

Disc brake noise

Pad installed incorrectly

Pad surface glazed

Disc warped

Caliper trouble

Cylinder damaged

Other noise

Bracket, nut, bolt, etc. not properly

mounted or tightened

Exhaust Smoke

Excessive white smoke

Throttle cable maladjusted

Brownish smoke

Air cleaner clogged

Main jet too large of fallen out

Starter plunger stuck open

Float level too high

APPENDIX 16-5

Troubleshooting Guide

Handling and/or Stability

Unsatisfactory

Handlebar hard to turn

Control Cable routing incorrect

Wiring routing incorrect

Steering stem nut too tight

Bearing ball damaged

Bearing race dented or worn

Steering s tem bearing lubrication inade-

quate

Steering stem bent

Tire air pressure too low

Handlebar shakes or excessively vibrates

Tire worn

Swingarm sleeve or needle bearing dam-

aged

Rim warped, or not balanced

Front, rear axle runout excessive

Wheel bearing worn

Handlebar holder loose

Steering stem head nut loose

Handlebar pulls to one side

Frame bent

Wheel misalignment

Swingarm bent or twisted

Swingarm pivot shaft runout excessive

Steering maladjusted

Steering stem bent

Front fork leg bent

Right/left front fork oil level uneven

Shock absorption unsatisfactory

(Too hard)

Front fork oil excessive

Front fork oil viscosity too high

Front fork leg bent

Front fork air pressure high

Tire air pressure too high

Rear shock absorber maladjusted

(Too soft)

Front fork oil insufficient and/or leaking

Front fork oil viscosity too low

Front fork, rear shock absorber spring weak

Rear shock absorber gas leaking

Rear shock absorber maladjusted

Brake Doesn’t Hold

Disc brake

Air in the brake line

Pad or disc worn

Brake fluid leak

Disc warped

Contaminated pads

Brake fluid deteriorated

Primary or secondary cup damaged

Master cylinder scratched inside

Brake maladjustment (lever or pedal play

excessive)

16-6 APPENDIX

Cable, Wire and Hose Routing

APPENDIX 16-7

Cable, Wire and Hose Routing

1. Throttle Cable

2. Clutch Cable

3. Engine Stop Switch Lead

4. Clamp

5. CDI Unit

6. Install the clamp to the frame so that its opening side faces outward.

7. Carburetor Leads

8. Carburetor Leads Connector

9. Main Harness

10. Do not slacken.

11. Clamp the main harness as shown.

12. Band

13. Run the clutch cable above the number plate mounting bracket.

A: KX250-R1 Model

B: KX250R6F Model ∼

16-8 APPENDIX

Cable, Wire and Hose Routing

APPENDIX 16-9

Cable, Wire and Hose Routing

1. To Engine Stop Switch

2. CDI Unit

3. Do not slacken.

4. Clamp the throttle cable, CDI unit leads and engine stop switch leads.

5. To Ignition Coil

6. Clamp the throttle cable. Be careful not to bite cable when installing the fuel tank. Run the main

harness under the frame. Install the clamp to the frame so that its opening side faces outward.

7. Carburetor Leads Connector

8. Magneto Leads Connector

9. Spark Plug Cap

10. Cooling Hose

11. Left Radiator

12. Clamp the magneto leads with the band.

13. Clamp the magneto leads.

14. Clamp the hose so that clamp cutting edge faces forwards.

15. Clamp the hose with the band.

16. Clamp the clutch cable.

17. Clamp the air vent hoses with clamps which are installed together with engine sprocket cover

and run them along with the engine sprocket cover.

18. Air Vent Hoses

19. Clamp the overflow hose and other hoses.

20. Left Radiator

21. Right Radiator

22. Radiator Overflow Hose

23. Run the radiator overflow hose so that it dose not touch the exhaust chamber.

24. Run the radiator overflow hose outside of the engine mount bracket.

25. Install the clamp to the frame so that its opening side faces outward.

26. Clamp

27. clamp the main harness as shown.

16-10 APPENDIX

Cable, Wire and Hose Routing

APPENDIX 16-11

Cable, Wire and Hose Routing

1. Clutch Cable

2. Clamp

3. Main Harness Ground Lead (Outside)

4. Ignition Coil Ground Lead (Inside)

5. Ignition Coil

6. Tighten together with the main harness ground lead and ignition coil ground lead with the ignition

coil mounting bolt.

7. Run the ignition coil lead inside of the radiator bracket.

16-12 APPENDIX

Cable, Wire and Hose Routing

APPENDIX 16-13

Cable, Wire and Hose Routing

1. Front Brake Reservoir

2. Banjo Bolts

3. Clamp

4. Clamp Brackets

5. Front Brake Disc

6. Front Fork Guard

7. Bleed Valves

8. Front Brake Caliper

9. Rear Brake Caliper

10. Caliper Guard

11. Clamps

12. Rear Brake Reservoir

13. Rear Brake M aster Cylinder

14. Bend the cotter pin end by along the joint pin.

15. Rear Brake Disc

16. Disk Guard

MODEL APPLICATION

Year Model Beginning Frame No.

2005 KX250-R1

JKAKXMRC□5A000001 or

JKAKX250RRA000001

2006 KX250R6F

JKAKXMRC□6A006001 or

JKAKX250RRA006001

2007 KX250R7F

JKAKXMRC□7A010001 or

JKAKX250RRA010001

□:This digit in the frame number changes from one machine to another.

Part No.99924-1340-04

Printed in Japan