LIT-11626-21-57

OWNER’S SE

WR450FX

OWNER'S SERVICE MANUAL

©2007 by Yamaha Motor Corporation, U.S.A.

1st Edition, June 2007

All rights reserved.

Any reprinting or unauthorized use

without the written permission of

Yamaha Motor Corporation U.S.A.

is expressly prohibited.

Printed in Japan

P/N. LIT-11626-21-57

INTRODUCTION

Congratulations on your purchase of a Yamaha

WR series. This model is the culmination of

Yamaha's vast experience in the production of

pacesetting racing machines. It represents the

highest grade of craftsmanship and reliability

that have made Yamaha a leader.

This manual explains operation, inspection, ba-

sic maintenance and tuning of your machine. If

you have any questions about this manual or

your machine, please contact your Yamaha

dealer.

The design and manufacture of this Yamaha

machine fully comply with the emissions stan-

dards for clean air applicable at the date of

manufacture. Yamaha has met these stan-

dards without reducing the performance or

economy of operation of the machine. To main-

tain these high standards, it is important that

you and your Yamaha dealer pay close atten-

tion to the recommended maintenance sched-

ules and operating instructions contained

within this manual.

Yamaha continually seeks advancements in

product design and quality. Therefore, while

this manual contains the most current product

information available at the time of printing,

there may be minor discrepancies between

your machine and this manual. If you have any

questions concerning this manual, please con-

sult your Yamaha dealer.

PLEASE READ THIS MANUAL CAREFULLY

AND COMPLETELY BEFORE OPERATING

THIS MACHINE. DO NOT ATTEMPT TO OP-

ERATE THIS MACHINE UNTIL YOU HAVE

ATTAINED A SATISFACTORY KNOWL-

EDGE OF ITS CONTROLS AND OPERATING

FEATURES AND UNTIL YOU HAVE BEEN

TRAINED IN SAFE AND PROPER RIDING

TECHNIQUES. REGULAR INSPECTIONS

AND CAREFUL MAINTENANCE, ALONG

WITH GOOD RIDING SKILLS, WILL ENSURE

THAT YOU SAFETY ENJOY THE CAPABILI-

TIES AND THE RELIABILITY OF THIS MA-

CHINE.

PARTICULARLY IMPORTANT

INFORMATION

The Safety Alert Symbol means ATTENTION!

BECOME ALERT! YOUR SAFETY IS IN-

VOLVED!

Failure to follow WARNING instructions could

result in severe injury or death to the machine

operator, a bystander, or a person inspecting or

repairing the machine.

A CAUTION indicates special precautions that

must be taken to avoid damage to the machine.

A NOTE provides key information to make pro-

cedures easier or clearer.

YAMAHA MOTOR CORPORATION, U.S.A.

WR MOTORCYCLE LIMITED WARRANTY

IMPORTANT NOTICE

This machine is designed for off-road use only.

It is illegal for this machine to be operated on

any public street, road, or highway. Off-road

use on public lands may be illegal. Please

check local regulations before riding.

1. THIS MACHINE IS TO BE OPERATED

BY AN EXPERIENCED RIDER ONLY.

Do not attempt to operate this machine

at maximum power until you are totally

familiar with its characteristics.

2. THIS MACHINE IS DESIGNED TO BE

RIDDEN BY THE OPERATOR ONLY.

Do not carry passengers on this ma-

chine.

3. ALWAYS WEAR PROTECTIVE APPAR-

EL.

When operating this machine, always

wear an approved helmet with goggles

or a face shield. Also wear heavy boots,

gloves, and protective clothing. Always

wear proper fitting clothing that will not

be caught in any of the moving parts or

controls of the machine.

4. ALWAYS MAINTAIN YOUR MACHINE IN

PROPER WORKING ORDER.

For safety and reliability, the machine

must be properly maintained. Always

perform the pre-operation checks indi-

cated in this manual. Correcting a me-

chanical problem before you ride may

prevent an accident.

5. GASOLINE IS HIGHLY FLAMMABLE.

Always turn off the engine while refuel-

ing. Take care to not spill any gasoline

on the engine or exhaust system. Never

refuel in the vicinity of an open flame, or

while smoking.

6. GASOLINE CAN CAUSE INJURY.

If you should swallow some gasoline,

inhale excess gasoline vapors, or allow

any gasoline to get into your eyes, con-

tact a doctor immediately. If any gaso-

line spills onto your skin or clothing,

immediately wash skin areas with soap

and water, and change your clothes.

7. ONLY OPERATE THE MACHINE IN AN

AREA WITH ADEQUATE VENTILATION.

Never start the engine or let it run for

any length of time in an enclosed area.

Exhaust fumes are poisonous. These

fumes contain carbon monoxide, which

by itself is odorless and colorless. Car-

bon monoxide is a dangerous gas

which can cause unconsciousness or

can be lethal.

8. PARK THE MACHINE CAREFULLY;

TURN OFF THE ENGINE.

Always turn off the engine if you are go-

ing to leave the machine. Do not park

the machine on a slope or soft ground

as it may fall over.

9. THE ENGINE, EXHAUST PIPE, MUF-

FLER, AND OIL TANK WILL BE VERY

HOT AFTER THE ENGINE HAS BEEN

RUN.

Be careful not to touch them or to allow

any clothing item to contact them dur-

ing inspection or repair.

10.PROPERLY SECURE THE MACHINE

BEFORE TRANSPORTING IT.

When transporting the machine in an-

other vehicle, always be sure it is prop-

erly secured and in an upright position

and that the fuel cock is in the "OFF"

position. Otherwise, fuel may leak out

of the carburetor or fuel tank.

TO THE NEW OWNER

This manual will provide you with a good basic

understanding of features, operation, and basic

maintenance and inspection items of this ma-

chine. Please read this manual carefully and

completely before operating your new ma-

chine. If you have any questions regarding the

operation or maintenance of your machine,

please consult your Yamaha dealer.

This manual should be considered a perma-

nent part of this machine and should remain

with it even if the machine is subsequently sold.

NOTICE

Some data in this manual may become out-

dated due to improvements made to this

model in the future. If there is any question

you have regarding this manual or your ma-

chine, please consult your Yamaha dealer.

HOW TO USE THIS MANUAL

FINDING THE REQUIRED PAGE

1. This manual consists of seven chapters; "General Information", "Specifications", "Regular inspec-

tion and adjustments", "Tuning", "Engine", "Chassis" and "Electrical".

2. The table of contents is at the beginning of the manual. Look over the general layout of the book

before finding then required chapter and item.

Bend the book at its edge, as shown, to find the required fore edge symbol mark and go to a page

for required item and description.

MANUAL FORMAT

All of the procedures in this manual are organized in a sequential, step-by-step format. The informa-

tion has been complied to provide the mechanic with an easy to read, handy reference that contains

comprehensive explanations of all disassembly, repair, assembly, and inspection operations.

In this revised format, the condition of a faulty component will precede an arrow symbol and the

course of action required will follow the symbol, e.g.,

• Bearings

Pitting/damage →Replace.

HOW TO READ DESCRIPTIONS

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 "1" is provided for removal and disassembly jobs.

2. Numbers "2" 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

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

4. A job instruction chart "4" 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 "5" are given in addition

to the exploded diagram and job instruction chart.

ILLUSTRATED SYMBOLS (Refer

to the illustration)

Illustrated symbols "1" to "7" are used to identi-

fy the specifications appearing in the text.

1.

With engine mounted

2.

Filling fluid

3.

Lubricant

4.

Special tool

5.

Tightening

6.

Specified value, Service limit

7.

Resistance (Ω), Voltage (V), Electric cur-

rent (A)

Illustrated symbols "8" to "13" in the exploded

diagrams indicate grade of lubricant and loca-

tion of lubrication point.

8.

Apply engine oil

9.

Apply molybdenum disulfide oil

10. Apply brake fluid

11. Apply lightweight lithium-soap base grease

12. Apply molybdenum disulfide grease

13. Apply silicone grease

Illustrated symbols "14" to "15" in the exploded

diagrams indicate where to apply a locking

agent and where to install new parts.

14. Apply locking agent (LOCTITE^®)

15. Use new one

TABLE OF CONTENTS

GENERAL INFORMATION

1

SPECIFICATIONS

2

REGULAR INSPECTION AND

ADJUSTMENTS

3

TUNING

4

ENGINE

5

CHASSIS

6

ELECTRICAL

7

CONTENTS

CHAPTER 1

GENERAL INFORMATION

DESCRIPTION ........................................... 1-1

MACHINE IDENTIFICATION ..................... 1-2

INCLUDED PARTS.................................... 1-3

IMPORTANT INFORMATION.................... 1-4

CHECKING OF CONNECTION ................. 1-6

SPECIAL TOOLS....................................... 1-7

CONTROL FUNCTIONS.......................... 1-11

MULTI-FUNCTION DISPLAY .................. 1-14

STARTING AND BREAK-IN.................... 1-21

TORQUE-CHECK POINTS...................... 1-24

CLEANING AND STORAGE ................... 1-25

CHAPTER 2

SPECIFICATIONS

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

MAINTENANCE SPECIFICATIONS.......... 2-4

TIGHTENING TORQUES......................... 2-14

LUBRICATION DIAGRAMS .................... 2-23

CABLE ROUTING DIAGRAM.................. 2-27

CHAPTER 3

REGULAR INSPECTION AND

ADJUSTMENTS

PERIODIC MAINTENANCE CHART FOR

THE EMISSION CONTROL SYSTEM ....... 3-1

GENERAL MAINTENANCE AND

LUBRICATION CHART ............................. 3-2

MAINTENANCE INTERVALS FOR

COMPETITION USE .................................. 3-4

PRE-OPERATION INSPECTION AND

MAINTENANCE ......................................... 3-8

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

CHASSIS.................................................. 3-25

ELECTRICAL........................................... 3-41

CHAPTER 4

TUNING

CHASSIS.................................................... 4-1

CHAPTER 5

ENGINE

RADIATOR................................................. 5-1

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

AIR INDUCTION SYSTEM....................... 5-17

CAMSHAFTS ........................................... 5-19

CYLINDER HEAD .................................... 5-26

VALVES AND VALVE SPRINGS ............ 5-30

CYLINDER AND PISTON ........................ 5-37

CLUTCH................................................... 5-42

OIL FILTER ELEMENT AND WATER

PUMP ....................................................... 5-48

BALANCER ............................................. 5-54

OIL PUMP ................................................ 5-57

KICK SHAFT AND SHIFT SHAFT........... 5-61

AC MAGNETO AND STARTER

CLUTCH................................................... 5-67

ENGINE REMOVAL................................. 5-73

CRANKCASE AND CRANKSHAFT........ 5-79

TRANSMISSION, SHIFT CAM AND

SHIFT FORK ............................................ 5-87

CHAPTER 6

CHASSIS

FRONT WHEEL AND REAR WHEEL ....... 6-1

FRONT BRAKE AND REAR BRAKE...... 6-10

FRONT FORK .......................................... 6-24

HANDLEBAR........................................... 6-35

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

SWINGARM ............................................. 6-48

REAR SHOCK ABSORBER.................... 6-55

CHAPTER 7

ELECTRICAL

ELECTRICAL COMPONENTS AND

WIRING DIAGRAM .................................... 7-1

IGNITION SYSTEM.................................... 7-4

ELECTRIC STARTING SYSTEM............... 7-8

CHARGING SYSTEM .............................. 7-16

THROTTLE POSITION SENSOR

SYSTEM................................................... 7-18

LIGHTING SYSTEM................................. 7-22

SIGNALING SYSTEM.............................. 7-24

1-1

DESCRIPTION

GENERAL INFORMATION

DESCRIPTION

• The machine you have purchased may differ slightly from those shown in the following.

• Designs and specifications are subject to change without notice.

1.

Clutch lever

2.

Hot starter lever

3.

Engine stop switch

4.

Multi-function display

5.

Main switch

6.

Start switch

7.

Front brake lever

8.

Throttle grip

9.

Radiator cap

10. Fuel tank cap

11. Taillight

12. Kickstarter crank

13. Fuel tank

14. Headlight

15. Radiator

16. Coolant drain bolt

17. Rear brake pedal

18. Valve joint

19. Fuel cock

20. Cold starter knob

21. Air cleaner

22. Catch tank

23. Drive chain

24. Shift pedal

25. Oil dipstick

26. Front fork

1