Yamaha YZF-R6 99 User manual

EB000000
YZF-R6
SERVICE MANUAL
1998 by Yamaha Motor Co., Ltd.
First edition, August 1998
All rights reserved. Any reproduction or
unauthorized use without the written
permission of Yamaha Motor Co., Ltd.
is expressly prohibited.

NOTE:
WARNING
CAUTION:
EB001000 NOTICE
This manual was produced by the Yamaha Motor Company, Ltd. primarily for use by Yamaha dealers
andtheirqualifiedmechanics.itisnotpossibletoincludealltheknowledgeofamechanicinonemanu-
al. Therefore, anyone who uses this book to perform maintenance and repairs on Yamaha vehicles
shouldhaveabasicunderstandingofmechanicsandthetechniquestorepairthesetypesofvehicles.
Repair and maintenance work attempted by anyone without this knowledge is likely to render the ve-
hicle unsafe and unfit for use.
Yamaha Motor Company,Ltd.iscontinuallystrivingtoimproveallofitsmodels.Modificationsandsig-
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.
Designs and specifications are subject to change without notice.
EB002000
IMPORTANT MANUAL INFORMATION
Particularly important information is distinguished in this manual by the following.
The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR
SAFETY IS INVOLVED!
Failuretofollow WARNINGinstructionscouldresultinsevereinjuryordeathto
themotorcycleoperator,abystander or apersoncheckingorrepairingthemo-
torcycle.
ACAUTIONindicatesspecialprecautionsthatmustbetakentoavoiddamage
to the motorcycle.
NOTE: A NOTE provides key information to make procedures easier or clearer.

126
4
5
7
3
8
EB003000 HOW TO USE THIS MANUAL
This manual is intended as a handy, easy-to-read reference book for the mechanic. Comprehensive
explanationsof all installation,removal, disassembly, assembly, repair andcheck procedures arelaid
out with the individual steps in sequential order.
1The manual is divided into chapters. An abbreviation and symbol in the upper right corner of each
page indicate the current chapter.
Refer to “SYMBOLS”.
2Each chapter is divided into sections. The current section title is shown at the top of each page,
exceptinChapter3(“PERIODICCHECKSANDADJUSTMENTS”),wherethesub-sectiontitle(-s)ap-
pears.
3Sub-section titles appear in smaller print than the section title.
4To help identify parts and clarify procedure steps, there are exploded diagrams at the start of each
removal and disassembly section.
5Numbers are given in the order of the jobs in the exploded diagram. A circled number indicates a
disassembly step.
6Symbols indicate parts to be lubricated or replaced.
Refer to “SYMBOLS”.
7A job instruction chart accompanies the exploded diagram, providing the order of jobs, names of
parts, notes in jobs, etc.
8Jobs requiring more information (such as special tools and technical data) are described sequen-
tially.

22
1
3
5
7
9
2
4
8
6
24 25
2321
19 2018
16 1715
1413
11 12
10
GEN
INFO SPEC
ENG
CARB
ELECCHAS
COOL
CHK
ADJ
TRBL
SHTG
EB004000
SYMBOLS
The following symbols are not relevant to every
vehicle.
Symbols 1to 9indicate the subject of each
chapter.
1General information
2Specifications
3Periodic checks and adjustments
4Engine
5Cooling system
6Carburetor(-s)
7Chassis
8Electrical system
9Troubleshooting
Symbols 10 to 17 indicate the following.
10 Serviceable with engine mounted
11 Filling fluid
12 Lubricant
13 Special tool
14 Tightening torque
15 Wear limit, clearance
16 Engine speed
17 Electrical data
Symbols 18 to 23 intheexplodeddiagramsindi-
cate the types of lubricants and lubrication
points.
18 Engine oil
19 Gear oil
20 Molybdenum disulfide oil
21 Wheel bearing grease
22 Lithium soap base grease
23 Molybdenum disulfide grease
Symbols 24 to 25 intheexplodeddiagramsindi-
cate the following.
24 Apply locking agent (LOCTITE)
25 Replace the part

GENERAL INFORMATION
SPECIFICATIONS
PERIODIC INSPECTION AND
ADJUSTMENT
ENGINE OVERHAUL
COOLING SYSTEM
CARBURETORS
CHASSIS
ELECTRICAL
TROUBLESHOOTING
GEN
INFO 1
SPEC 2
3
ENG 4
COOL 5
CARB 6
CHAS 7
ELEC 8
TRBL
SHTG 9
CHK
ADJ
INDEX

GEN
INFO
CHAPTER 1.
GENERAL INFORMATION
MOTORCYCLE IDENTIFICATION 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VEHICLE IDENTIFICATION NUMBER 1-1. . . . . . . . . . . . . . . . . . . . . . . . .
MODEL CODE 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. . . . . . . . . . . . . . . . . . . . . . . .
USING A DYNAMOMETER 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LOCK WASHERS/PLATES AND COTTER PINS 1-3. . . . . . . . . . . . . . . .
BEARINGS AND OIL SEALS 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CIRCLIPS 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHECKING THE CONNECTIONS 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FEATURES 1-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AIR INTAKE SYSTEM 1-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
THERMOSTAT 1-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IGNITION SYSTEM 1-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS 1-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-1
MOTORCYCLE IDENTIFICATION GEN
INFO
EB100000
GENERAL INFORMATION
MOTORCYCLE IDENTIFICATION
EB100010
VEHICLE IDENTIFICATION NUMBER
Thevehicleidentificationnumber 1isstamped
into the right side of the steering head pipe.
EB100020
MODEL CODE
The model code label 1is affixed to the frame.
This information will be needed to order spare
parts.

1-2
IMPORTANT INFORMATION GEN
INFO
EB102000
IMPORTANT INFORMATION
PREPARATION FOR REMOVAL AND DIS-
ASSEMBLY
1. Beforeremovalanddisassembly, removeall
dirt, mud, dust, and foreign material.
2. Use only the proper tools and cleaning
equipment.
Refer to “SPECIAL TOOLS”.
3. When disassembling, always keep mated
parts together. This includes gears, cylin-
ders, pistons and other parts that have been
“mated” through normal wear. Mated parts
mustalwaysbe reused orreplacedasan as-
sembly.
4. During disassembly, clean all of the parts
and place them in trays in the order of disas-
sembly. This will speed up assembly and al-
low for the correct installation of all parts.
5. Keep all parts away from any source of fire.
EB102010
REPLACEMENT PARTS
Use only genuine Yamaha parts for all replace-
ments. Use oil and grease recommended by
Yamaha for all lubrication jobs.
Otherbrandsmay be similar infunctionandap-
pearance, but inferior in quality.
EB102020
GASKETS, OIL SEALS AND O-RINGS
1. When overhauling the engine, replace all
gaskets, seals, and O-rings. All gasket sur-
faces, oil seal lips, and O-rings must be
cleaned.
2. During reassembly, properly oil all mating
parts and bearings and lubricate the oil seal
lips with grease.

1-3
IMPORTANT INFORMATION GEN
INFO
CAUTION:
USING A DYNAMOMETER
The YZF-R6 has a carbon muffler that may
change color when exposed to high tempera-
tures. Therefore, when using a dynamometer
always use a fan to cool the muffler.
EB102030
LOCK WASHERS/PLATES AND COTTER
PINS
After removal, replace all lock washers/plates
1andcotterpins.Afterthe boltornuthasbeen
tightenedto specification,bendthelockwasher
tabs and the cotter pin ends along a flat of the
bolt or nut.
EB102040
BEARINGS AND OIL SEALS
1. Install bearings and oil seals so that the
manufacturer’s marks or numbers are vis-
ible. When installing oil seals, lubricate the
oil seal lips with a light coat of lithium soap
base grease. Oil bearings liberally when
installing, if appropriate.
1Oil seal
Donot spinthebearing withcompressedair
because this will damage the bearing sur-
faces.
1Bearing
EB102050
CIRCLIPS
Before reassembly, check all circlips carefully
and replace damaged or distorted circlips. Al-
ways replace piston pin clips after one use.
When installing a circlip 1, make sure that the
sharp-edged corner 2is positioned opposite
the thrust 3that the circlip receives.
4Shaft