Yamaha 2003 YFZ450S User manual

YFZ450S
5TG2-AE1
SERVICE MANUAL

EBS00000
YFZ450S
SERVICE MANUAL
©2003 by Yamaha Motor Co., Ltd.
First Edition, April 2003
All rights reserved.
Any reproduction or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.

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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
manual, 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.
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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 damage
to the machine.
A NOTE provides key information to make procedures easier or clearer.
WARNING
CAUTION:
NOTE:

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HOW TO USE THIS MANUAL
MANUAL ORGANIZATION
This manual consists of chapters for the main categories of subjects. (See “symbols”)
1st title 1: This is the title of the chapter with its symbol in the upper right corner of each page.
2nd title 2: 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 3: 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 4is provided for removal and disassembly jobs.
2. Numbers 5are 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
6. The meanings of the symbol marks are given on the next page.
4. A job instruction chart 7accompanies 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 8are given in addition
to the exploded diagram and the job instruction chart.

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SYMBOLS
The following symbols are not relevant to
every machine.
Symbols 1to 9indicate the subject of each
chapter.
1General information
2Specifications
3Periodic checks and adjustments
4Engine
5Cooling system
6Carburetor
7Chassis
8Electrical
9Troubleshooting
Symbols 0to Gindicate the following
0Serviceable with engine mounted
AFilling fluid
BLubricant
CSpecial tool
DTorque
EWear limit, clearance
FEngine speed
GElectrical data (Ω, V, A)
Symbols Hto Nin the exploded diagrams
indicate the types of lubricants and lubrication
points.
HApply engine oil
IApply gear oil
JApply molybdenum disulfide oil
KApply wheel bearing grease
LApply lithium-soap-based grease
MApply molybdenum disulfide grease
Symbols Nto Oin the exploded diagrams
indicate where to apply a locking agent Nand
when to install a new part O.
NApply the locking agent (LOCTITE®)
OReplace
12
34
56
78
90
AB
CD
EFG
HIJ
KLM
NO
GEN
INFO SPEC
CHK
ADJ ENG
COOL CARB
CHAS
–+
ELEC
TRBL
SHTG
T
R
.
.
EGM
BLS M
LT
New

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TABLE OF CONTENTS
GENERAL INFORMATION GEN
INFO 1
SPECIFICATIONS SPEC 2
PERIODIC CHECKS AND
ADJUSTMENTS CHK
ADJ 3
ENGINE ENG 4
COOLING SYSTEM COOL 5
CARBURETOR CARB 6
CHASSIS CHAS 7
ELECTRICAL ELEC 8
TROUBLESHOOTING TRBL
SHTG
9
–+

GEN
INFO 1

GEN
INFO
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 .....................................1-3
BEARINGS AND OIL SEALS ....................................................................1-3
CIRCLIPS ..................................................................................................1-3
CHECKING THE CONNECTIONS............................................................1-4
SPECIAL TOOLS ............................................................................................1-5