SERVICE MANUAL

YFM250RX

4D3-28197-10

LIT-11616-21-22

2008

YFM250RX

SERVICE MANUAL

© 2007 by Yamaha Motor

Corporation, U.S.A.

First Edition, July 2007

All rights reserved.

Any reproduction or unauthorized use

without the written permission of

Yamaha Motor Corporation, U.S.A.

is expressly prohibited.

Printed in U.S.A

LIT-11616-21-22

EBS00001

EBS00002

NOTICE

This manual was produced by the Yamaha Motor Company primarily for use by Yamaha dealers and

their qualified mechanics. It is not possible to include all the knowledge of a mechanic in one man-

ual, so it is assumed that anyone who uses this book to perform maintenance and repairs on

Yamaha machine has a basic understanding of the mechanical ideas and the procedures of

machine repair. Repairs attempted by anyone without this knowledge are likely to render the

machine unsafe and unfit for use.

Yamaha Motor Company, Ltd. is continually striving to improve all its models. Modifications and sig-

nificant changes in specifications or procedures will be forwarded to all authorized Yamaha dealers

and will appear in future editions of this manual where applicable.

NOTE:

Designs and specifications are subject to change without notice.

EBS00003

IMPORTANT INFORMATION

Particularly important information is distinguished in this manual by the following notations.

The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR

SAFETY IS INVOLVED!

Failure to follow WARNING instructions could result in severe injury or death

to the machine operator, a bystander or a person checking or repairing the

machine.

A CAUTION indicates special precautions that must be taken to avoid dam-

age to the machine.

A NOTE provides key information to make procedures easier or clearer.

WARNING

CAUTION:

NOTE:

EBS00004

HOW TO USE THIS MANUAL

MANUAL ORGANIZATION

This manual consists of chapters for the main categories of subjects. (See “symbols”)

1st title

: This is the title of the chapter with its symbol in the upper right corner of each page.

2nd title

: This title indicates the section of the chapter and only appears on the first page of each

section. It is located in the upper left corner of the page.

3rd title

: This title indicates a sub-section that is followed by step-by-step procedures accompa-

nied by corresponding illustrations.

EXPLODED DIAGRAMS

To help identify parts and clarify procedure steps, there are exploded diagrams at the start of each

removal and disassembly section.

1. An easy-to-see exploded diagram

is provided for removal and disassembly jobs.

2. Numbers

are given in the order of the jobs in the exploded diagram. A number that is enclosed

by a circle indicates a disassembly step.

3. An explanation of jobs and notes is presented in an easy-to-read way by the use of symbol marks

. The meanings of the symbol marks are given on the next page.

4. A job instruction chart

accompanies the exploded diagram, providing the order of jobs, names

of parts, notes in jobs, etc.

5. For jobs requiring more information, the step-by-step format supplements

are given in addition

to the exploded diagram and the job instruction chart.

GEN

INFO

CHAS

EBS00006

SYMBOLS

The following symbols are not relevant to every

machine.

Symbols

to

indicate the subject of each

chapter.

General information

Specifications

Periodic checks and adjustments

Engine

Carburetor

Chassis

Electrical

Troubleshooting

Symbols

to

indicate the following

Serviceable with engine mounted

Filling fluid

Lubricant

Special tool

Torque

Wear limit, clearance

Engine speed

Electrical data (Ω, V, A)

Symbols

to

in the exploded diagrams

indicate the types of lubricants and lubrication

points.

Apply engine oil

Apply gear oil

Apply molybdenum disulfide oil

Apply brake fluid

Apply wheel bearing grease

Apply lithium-soap-based grease

Apply molybdenum disulfide grease

Apply silicone grease

Symbols

to

in the exploded diagrams

indicate where to apply a locking agent

and

when to install a new part

.

Apply the locking agent (LOCTITE^®)

Replace

EBS00008 TABLE OF CONTENTS

GENERAL INFORMATION

GEN

INFO 1

SPECIFICATIONS

SPEC 2

PERIODIC CHECKS AND

ADJUSTMENTS

CHK

ADJ 3

ENGINE

ENG 4

CARBURETOR

CARB 5

CHASSIS

CHAS 6

ELECTRICAL

ELEC 7

TROUBLESHOOTING

TRBL

SHTG 8

CHAPTER 1

GENERAL INFORMATION

MACHINE IDENTIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

VEHICLE IDENTIFICATION NUMBER. . . . . . . . . . . . . . . . . . . . . . . . 1-1

MODEL LABEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

IMPORTANT INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

PREPARATION FOR REMOVAL AND DISASSEMBLY . . . . . . . . . . 1-2

REPLACEMENT PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

GASKETS, OIL SEALS AND O-RINGS . . . . . . . . . . . . . . . . . . . . . . . 1-2

LOCK WASHERS/PLATES AND COTTER PINS . . . . . . . . . . . . . . . 1-2

BEARINGS AND OIL SEALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

CIRCLIPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

CHECKING THE CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

SPECIAL TOOLS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

CHAPTER 2

SPECIFICATIONS

GENERAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

ENGINE SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

CHASSIS SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11

ELECTRICAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

TIGHTENING TORQUES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15

ENGINE TIGHTENING TORQUES . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15

CHASSIS TIGHTENING TORQUES . . . . . . . . . . . . . . . . . . . . . . . . . 2-17

HOW TO USE THE CONVERSION TABLE . . . . . . . . . . . . . . . . . . . . . . 2-19

GENERAL TIGHTENING TORQUE SPECIFICATIONS . . . . . . . . . . . . . 2-19

LUBRICATION POINTS AND LUBRICANT TYPES . . . . . . . . . . . . . . . . 2-20

ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

OIL FLOW DIAGRAMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22

CABLE ROUTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25

CHAPTER 3

PERIODIC CHECKS AND ADJUSTMENTS

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

PERIODIC MAINTENANCE CHART FOR THE EMISSION CONTROL

SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

GENERAL MAINTENANCE AND LUBRICATION CHART . . . . . . . . . . 3-2

SEAT, FENDERS AND FUEL TANK. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

SEAT, FRONT FENDER AND HEADLIGHTS . . . . . . . . . . . . . . . . . . 3-4

FOOT PROTECTORS AND ENGINE SKID PLATE . . . . . . . . . . . . . . 3-5

REAR FENDER AND AIR FILLTER CASE. . . . . . . . . . . . . . . . . . . . . 3-6

FUEL TANK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

ADJUSTING THE VALVE CLEARANCE . . . . . . . . . . . . . . . . . . . . . . 3-9

ADJUSTING THE ENGINE IDLING SPEED. . . . . . . . . . . . . . . . . . . . 3-11

ADJUSTING THE THROTTLE LEVER FREE PLAY . . . . . . . . . . . . . 3-12

ADJUSTING THE SPEED LIMITER . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13

CHECKING THE SPARK PLUG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15

CHECKING THE IGNITION TIMING . . . . . . . . . . . . . . . . . . . . . . . . . 3-16

MEASURING THE COMPRESSION PRESSURE . . . . . . . . . . . . . . . 3-17

CHECKING THE ENGINE OIL LEVEL . . . . . . . . . . . . . . . . . . . . . . . . 3-19

CHANGING THE ENGINE OIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20

ADJUSTING THE CLUTCH CABLE . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22

CLEANING THE AIR FILTER ELEMENT . . . . . . . . . . . . . . . . . . . . . . 3-23

CLEANING THE SPARK ARRESTER . . . . . . . . . . . . . . . . . . . . . . . . 3-25

CHASSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26

ADJUSTING THE FRONT BRAKE . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26

ADJUSTING THE BRAKE LEVER (For adjustment type model) . . . . 3-26

ADJUSTING THE REAR BRAKE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26

ADJUSTING THE PARKING BRAKE . . . . . . . . . . . . . . . . . . . . . . . . . 3-27

CHECKING THE BRAKE FLUID LEVEL . . . . . . . . . . . . . . . . . . . . . . 3-28

CHECKING THE FRONT BRAKE PADS . . . . . . . . . . . . . . . . . . . . . . 3-29

CHECKING THE REAR BRAKE PADS . . . . . . . . . . . . . . . . . . . . . . . 3-30

ADJUSTING THE REAR BRAKE LIGHT SWITCH. . . . . . . . . . . . . . . 3-31

CHECKING THE BRAKE HOSES . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31

BLEEDING THE HYDRAULIC BRAKE SYSTEM . . . . . . . . . . . . . . . . 3-32

ADJUSTING THE SHIFT PEDAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34

ADJUSTING THE DRIVE CHAIN SLACK. . . . . . . . . . . . . . . . . . . . . . 3-35

CHECKING THE STEERING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . 3-36

ADJUSTING THE TOE-IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37

CHECKING THE FRONT AND REAR SHOCK ABSORBERS. . . . . . 3-38

ADJUSTING THE FRONT SHOCK ABSORBERS . . . . . . . . . . . . . . . 3-39

ADJUSTING THE REAR SHOCK ABSORBER . . . . . . . . . . . . . . . . . 3-40

CHECKING THE TIRES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41

CHECKING THE WHEELS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43

CHECKING AND LUBRICATING THE CABLES . . . . . . . . . . . . . . . . 3-43

LUBRICATING THE LEVERS AND PEDALS. . . . . . . . . . . . . . . . . . . 3-44

ELECTRICAL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45

CHECKING AND CHARGING THE BATTERY . . . . . . . . . . . . . . . . . 3-45

CHECKING THE FUSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52

ADJUSTING THE HEADLIGHT BEAM. . . . . . . . . . . . . . . . . . . . . . . . 3-53

REPLACING A HEADLIGHT BULB . . . . . . . . . . . . . . . . . . . . . . . . . . 3-54

CHAPTER 4

ENGINE

ENGINE REMOVAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

MUFFLER AND EXHAUST PIPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

INSTALLING THE EXHAUST PIPE AND MUFFLER . . . . . . . . . . . . . 4-2

LEADS, CABLES AND HOSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

ENGINE MOUNTING BOLTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

INSTALLING THE ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

CYLINDER HEAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

REMOVING THE CYLINDER HEAD . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

CHECKING THE CYLINDER HEAD. . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

CHECKING THE TIMING CHAIN GUIDES . . . . . . . . . . . . . . . . . . . . 4-11

CHECKING THE TIMING CHAIN TENSIONERS. . . . . . . . . . . . . . . . 4-11

INSTALLING THE CYLINDER HEAD. . . . . . . . . . . . . . . . . . . . . . . . . 4-12

ROCKER ARM, CAMSHAFT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

REMOVING THE ROCKER ARMS AND CAMSHAFT . . . . . . . . . . . . 4-16

CHECKING THE CAMSHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17

CHECKING THE ROCKER ARMS AND ROCKER ARM

SHAFTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18

INSTALLING THE CAMSHAFT AND ROCKER ARMS . . . . . . . . . . . 4-19

VALVES AND VALVE SPRINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21

REMOVING THE VALVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22

CHECKING THE VALVES AND VALVE GUIDES . . . . . . . . . . . . . . . 4-23

CHECKING THE VALVE SEATS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25

CHECKING THE VALVE SPRINGS . . . . . . . . . . . . . . . . . . . . . . . . . . 4-28

INSTALLING THE VALVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29

CYLINDER AND PISTON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31

REMOVING THE PISTON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-32

CHECKING THE CYLINDER AND PISTON. . . . . . . . . . . . . . . . . . . . 4-32

CHECKING THE PISTON RINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34

CHECKING THE PISTON PIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-36

INSTALLING THE PISTON AND CYLINDER. . . . . . . . . . . . . . . . . . . 4-37

CLUTCH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-39

REMOVING THE CLUTCH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-43

CHECKING THE FRICTION PLATES . . . . . . . . . . . . . . . . . . . . . . . . 4-44

CHECKING THE CLUTCH PLATES . . . . . . . . . . . . . . . . . . . . . . . . . 4-44

CHECKING THE CLUTCH SPRINGS . . . . . . . . . . . . . . . . . . . . . . . . 4-45

CHECKING THE CLUTCH HOUSING . . . . . . . . . . . . . . . . . . . . . . . . 4-45

CHECKING THE CLUTCH BOSS . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45

CHECKING THE PRESSURE PLATE . . . . . . . . . . . . . . . . . . . . . . . . 4-45

CHECKING THE CLUTCH PUSH RODS . . . . . . . . . . . . . . . . . . . . . . 4-46

CHECKING THE PRIMARY DRIVE GEAR . . . . . . . . . . . . . . . . . . . . 4-46

INSTALLING THE CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46

OIL PUMP AND BLANCER WEIGHT GEAR . . . . . . . . . . . . . . . . . . . . . 4-50

REMOVING THE BALANCER WEIGHT GEAR AND OIL PUMP. . . . 4-53

CHECKING THE OIL PUMP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-53

CHECKING THE BALANCER WEIGHT GEAR . . . . . . . . . . . . . . . . . 4-54

ASSENBLING THE BALANCER DRIVE GEAR . . . . . . . . . . . . . . . . . 4-55

INSTALLING THE OIL PUMP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-55

INSTALLING THE BALANCER WEIGHT GEAR . . . . . . . . . . . . . . . . 4-56

SHIFT SHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-57

CHECKING THE SHIFT SHAFT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-58

CHECKING THE STOPPER LEVER . . . . . . . . . . . . . . . . . . . . . . . . . 4-58

INSTALLING THE SHIFT SHAFT. . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-58

PICKUP COIL ROTOR AND STARTER CLUTCH . . . . . . . . . . . . . . . . . 4-60

REMOVING THE PICKUPCOIL ROTOR . . . . . . . . . . . . . . . . . . . . . . 4-62

CHECKING THE STARTER CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . 4-63

INSTALLING THE PICKUP COIL ROTOR . . . . . . . . . . . . . . . . . . . . . 4-64

CRANKCASE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-66

DISASSEMBLING THE CRANKCASE . . . . . . . . . . . . . . . . . . . . . . . . 4-69

CHECKING THE CRANKCASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-70

ASSEMBLING THE CRANKCASE . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-70

CRANKSHAFT ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-72

REMOVING THE CRANKSHAFT ASSEMBLY. . . . . . . . . . . . . . . . . . 4-73

REMOVING THE PLUNGER SEAL . . . . . . . . . . . . . . . . . . . . . . . . . . 4-73

CHECKING THE CRANKSHAFT AND CONNECTING ROD. . . . . . . 4-73

CHECKING THE TIMING CHAIN, CRANKSHAFT SPROCKET

AND TIMING CHAIN GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-74

INSTALLING THE PLUNGER SEAL . . . . . . . . . . . . . . . . . . . . . . . . . 4-75

INSTALLING THE CRANKSHAFT ASSEMBLY . . . . . . . . . . . . . . . . . 4-75

TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-77

REMOVING THE TRANSMISSION . . . . . . . . . . . . . . . . . . . . . . . . . . 4-80

CHECKING THE SHIFT FORKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-80

CHECKING THE SHIFT DRUM ASSEMBLY . . . . . . . . . . . . . . . . . . . 4-81

CHECKING THE TRANSMISSION. . . . . . . . . . . . . . . . . . . . . . . . . . . 4-81

INSTALLING THE SHIFT FORKS AND SHIFT DRUM

ASSEMBLY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-82

CHAPTER 5

CARBURETOR

CARBURETOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

CHECKING THE CARBURETOR. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

ASSEMBLING THE CARBURETOR . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

INSTALLING THE CARBURETOR JOINT . . . . . . . . . . . . . . . . . . . . . 5-7

INSTALLING THE CARBURETOR. . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

CHAPTER 6

CHASSIS

FRONT AND REAR WHEELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

FRONT WHEELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

REAR WHEELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

CHECKING THE WHEELS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

CHECKING THE WHEEL HUBS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

CHECKING THE BRAKE DISCS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5

INSTALLING THE FRONT WHEEL HUB BEARINGS . . . . . . . . . . . . 6-6

INSTALLING THE FRONT BRAKE DISCS . . . . . . . . . . . . . . . . . . . . 6-6

INSTALLING THE FRONT WHEELS . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

INSTALLING THE WHEEL HUBS . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

REAR AXLE AND REAR AXLE HUB . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8

REMOVING THE REAR AXLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10

CHECKING THE REAR AXLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11

CHECKING THE DRIVEN SPROCKET . . . . . . . . . . . . . . . . . . . . . . . 6-11

CHECKING THE BRAKE DISC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11

INSTALLING THE DRIVEN SPROCKET . . . . . . . . . . . . . . . . . . . . . . 6-11

INSTALLING THE REAR AXLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11

FRONT AND REAR BRAKES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13

FRONT BRAKE PADS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13

REAR BRAKE PADS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14

REPLACING THE FRONT BRAKE PADS . . . . . . . . . . . . . . . . . . . . . 6-15

REPLACING THE REAR BRAKE PADS . . . . . . . . . . . . . . . . . . . . . . 6-17

FRONT BRAKE MASTER CYLINDER . . . . . . . . . . . . . . . . . . . . . . . . 6-19

REAR BRAKE MASTER CYLINDER . . . . . . . . . . . . . . . . . . . . . . . . . 6-21

CHECKING THE MASTER CYLINDERS . . . . . . . . . . . . . . . . . . . . . . 6-24

ASSEMBLING THE FRONT BRAKE MASTER CYLINDER . . . . . . . 6-25

ASSEMBLING THE REAR BRAKE MASTER CYLINDER . . . . . . . . 6-25

INSTALLING THE FRONT BRAKE MASTER CYLINDER . . . . . . . . . 6-26

INSTALLING THE REAR BRAKE MASTER CYLINDER . . . . . . . . . . 6-28

FRONT BRAKE CALIPERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-30

REAR BRAKE CALIPER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-32

REMOVING THE PARKING BRAKE CABLE . . . . . . . . . . . . . . . . . . . 6-34

DISASSEMBLING THE FRONT AND REAR BRAKE CALIPERS . . . 6-34

CHECKING THE FRONT AND REAR BRAKE CALIPERS . . . . . . . . 6-35

ASSEMBLING THE FRONT BRAKE CALIPERS . . . . . . . . . . . . . . . . 6-36

ASSEMBLING THE REAR BRAKE CALIPER . . . . . . . . . . . . . . . . . . 6-36

INSTALLING THE FRONT BRAKE CALIPERS . . . . . . . . . . . . . . . . . 6-38

INSTALLING THE REAR BRAKE CALIPER . . . . . . . . . . . . . . . . . . . 6-40

STEERING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-42

HANDLEBAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-42

REMOVING THE CLUTCH SWITCH . . . . . . . . . . . . . . . . . . . . . . . . . 6-44

REMOVING THE HANDLEBAR GRIPS . . . . . . . . . . . . . . . . . . . . . . 6-44

CHECKING THE HANDLEBAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-44

INSTALLING THE HANDLEBAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-45

INSTALLING THE HANDLEBAR GRIPS . . . . . . . . . . . . . . . . . . . . . . 6-45

INSTALLING THE CLUTCH LEVER. . . . . . . . . . . . . . . . . . . . . . . . . . 6-46

INSTALLING THE BRAKE MASTER CYLINDER . . . . . . . . . . . . . . . 6-46

STEERING STEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-47

CHECKING THE STEERING STEM. . . . . . . . . . . . . . . . . . . . . . . . . . 6-48

INSTALLING THE STEERING STEM. . . . . . . . . . . . . . . . . . . . . . . . . 6-48

INSTALLING THE LOCK WASHER . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48

TIE-RODS AND STEERING KNUCKLES. . . . . . . . . . . . . . . . . . . . . . 6-49

REMOVING THE STEERING KNUCKLES. . . . . . . . . . . . . . . . . . . . . 6-50

CHECKING THE TIE-RODS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-50

CHECKING THE STEERING KNUCKLES . . . . . . . . . . . . . . . . . . . . . 6-50

INSTALLING THE TIE-RODS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-50

FRONT ARMS AND FRONT SHOCK ABSORBER ASSEMBLIES . . . . 6-51

REMOVING THE FRONT ARMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53

CHECKING THE FRONT ARMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53

CHECKING THE FRONT SHOCK ABSORBERS . . . . . . . . . . . . . . . 6-53

CHECKING THE BALL JOINTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54

INSTALLING THE FRONT ARMS . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54

REAR SHOCK ABSORBER, SWINGARM AND DRIVE CHAIN . . . . . . 6-55

HANDLING THE REAR SHOCK ABSORBER . . . . . . . . . . . . . . . . . . 6-57

DISPOSING OF A REAR SHOCK ABSORBER . . . . . . . . . . . . . . . . . 6-57

REMOVING THE REAR SHOCK ABSORBER. . . . . . . . . . . . . . . . . . 6-58

CHECKING THE REAR SHOCK ABSORBER . . . . . . . . . . . . . . . . . . 6-58

REMOVING THE SWINGARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58

CHECKING THE SWINGARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-59

CHECKING THE DRIVE CHAIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60

INSTALLING THE SWINGARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-62

INSTALLING THE DRIVE SPROCKET . . . . . . . . . . . . . . . . . . . . . . . 6-62

CHAPTER 7

ELECTRICAL

ELECTRICAL COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

CHECKING SWITCH CONTINUITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

CHECKING THE SWITCHES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

CHECKING THE BULBS AND BULB SOCKETS. . . . . . . . . . . . . . . . . . 7-5

TYPES OF BULBS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5

CHECKING THE CONDITION OF THE BULBS. . . . . . . . . . . . . . . . . 7-5

CHECKING THE CONDITION OF THE BULB SOCKETS . . . . . . . . 7-7

IGNITION SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8

CIRCUIT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9

ELECTRIC STARTING SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13

CIRCUIT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13

STARTING CIRCUIT CUT-OFF SYSTEM OPERATION . . . . . . . . . . 7-14

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15

STARTER MOTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19

CHECKING THE STARTER MOTOR. . . . . . . . . . . . . . . . . . . . . . . . . 7-21

ASSEMBLING THE STARTER MOTOR . . . . . . . . . . . . . . . . . . . . . . 7-23

CHARGING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-24

CIRCUIT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-24

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-25

LIGHTING SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-27

CIRCUIT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-27

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-28

CHECKING THE LIGHTING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . 7-29

SIGNAL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-31

CIRCUIT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-31

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-32

CHECKING THE SIGNALING SYSTEM. . . . . . . . . . . . . . . . . . . . . . . 7-33

CHAPTER 8

TROUBLESHOOTING

STARTING FAILURE/HARD STARTING . . . . . . . . . . . . . . . . . . . . . . . . 8-1

FUEL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

ELECTRICAL SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

COMPRESSION SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2

POOR IDLE SPEED PERFORMANCE . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2

POOR IDLE SPEED PERFORMANCE . . . . . . . . . . . . . . . . . . . . . . . 8-2

POOR MEDIUM AND HIGH-SPEED PERFORMANCE . . . . . . . . . . . . . 8-2

POOR MEDIUM AND HIGH-SPEED PERFORMANCE . . . . . . . . . . . 8-2

FAULTY GEAR SHIFTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

HARD SHIFTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

SHIFT PEDAL DOES NOT MOVE . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

JUMPS OUT GEAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

CLUTCH SLIPPING/DRAGGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

CLUTCH SLIPPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

CLUTCH DRAGGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3

OVERHEATING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

OVERHEATING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

FAULTY BRAKE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

POOR BRAKING EFFECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

SHOCK ABSORBER MALFUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

MALFUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

UNSTABLE HANDLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

UNSTABLE HANDLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

LIGHTING SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

HEADLIGHT DOES NOT COME ON . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

TAIL/BRAKE LIGHT DOES NOT LIGHT . . . . . . . . . . . . . . . . . . . . . . 8-5

BULB BURNT OUT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5

TAIL/BRAKE LIGHT BULB BURNT OUT . . . . . . . . . . . . . . . . . . . . . 8-5