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

1-4
CHECKING THE CONNECTIONS GEN
INFO
NOTE:
NOTE:
NOTE:
EB103000
CHECKING THE CONNECTIONS
Check the leads, couplers, and connectors for
stains, rust, moisture, etc.
1. Disconnect:
lead
coupler
connector
2. Check:
lead
coupler
connector
Moisture Dry with an air blower.
Rust/stains Connect and disconnect sev-
eral times.
3. Check:
all connections
Loose connection Connect properly.
If the pin 1on the terminal is flattened, bend it
up.
4. Connect:
lead
coupler
connector
Make sure that all connections are tight.
5. Check:
continuity
(with the pocket tester)
Pocket tester
90890-03112
If there is no continuity, clean the terminals.
When checking the wire harness, perform
steps (1) to (3).
As a quick remedy, use a contact revitalizer
available at most part stores.

1-5
FEATURES GEN
INFO
Former thermostat
Temperature
Time
New thermostat
Temperature
Time
FEATURES
AIR INTAKE SYSTEM
System diagram
This system is designed to improve the power while riding a motorcycle at a high speed by increasing
theairintakeefficiencybymeansofpressurizingtheairfiltercase 2wheretheairistakeninviatheair
duct 1from the air intake port located under the headlight.
The system also delivers air pressure from the air filter case to the carburetor side.
Theairpressureisoperatedtothefuellevelinthecarburetortosupplytheappropriatefueltoincrease
the power.
The air chamber 3is also installed between the air filter case and carburetor for delivery of stabilized
air pressure to the carburetor.
THERMOSTAT
Coolant flow is controlled by the thermostat of
which flow control valve 1is newly developed
for avoiding quick temperature change.
(Refer to the graphs)
2Notch groove

1-6
FEATURES GEN
INFO
1) 2)
3) 4)
1 CDI unit
2 Voltage converter
3 Condenser
4 Ignition coil
5 Spark plug
6 Ignition timing controller
7 Pickup coil
8 T. P. S.
9 Speed sensor
10 Battery
11 Rectifier/regulator
12 AC magneto
13 Stator coil
Flow control operation
1) When valve is closed
The lip 1seals the coolant.
2) When valve is set as low-lift
The 2nd lip 2seals the coolant.
To reduce the water temperature change,
the coolant starts flowing through the notch
depending on its area at asection.
3) When the valve is set as middle-lift
The 3rd lip 3seals the coolant.
Thecoolantflowsthroughthenotchdepend-
ing on its area at bsection.
This flow rate is larger than the case of 2).
4) When the valve is set as high-lift
In the same way as the regular thermostat
control, the coolant flows through clearance
cbetween the valve and flange.
IGNITION SYSTEM
1. DC CDI
1) Features
* Battery is used as the power source.
* Stabilized spark performance is provided in the range from a low speed to high speed since the
battery is used as the power source.
* Compact AC magneto design is possible since the source coil is unnecessary.
* Compact ignition coil design is possible since the condenser stores electricity.
Plug top ignition coil is equipped in which the plug cap and ignition coil are integrated.
* Stator coil can supply power even if the battery is running out.
2) Circuit diagram

1-7
FEATURES GEN
INFO
2. Ignition coil
Compactandrightweightdesignisprovided
since the plug top ignition coil is equipped in
which the plug cap ignition coil are inte-
grated.
Hightension cord wascut an endto use and
ignition energy loss has become lower.
3. Spark plug
The 2-pole spark plug is applied to improve
the ignition quality and combustion efficien-
cy.

1-8
SPECIAL TOOLS GEN
INFO
EB104000
SPECIAL TOOLS
The following special tools are necessary for complete and accurate tune-up and assembly.
Useonlytheappropriatespecialtoolsasthiswillhelppreventdamagecausedbytheuseofinappropri-
ate tools or improvised techniques.
When placing an order, refer to the list provided below to avoid any mistakes.
Tool No. Tool name/Function Illustration
Flywheel puller
90890-01362
Adapter
90890-04089
Flywheel puller
Adapter
This tool is used to remove the generator ro-
tor.
90890-01701
Sheave holder
This tool is used to hold the generator rotor
when removing or installing the generator ro-
tor bolt or pickup coil rotor bolt.
90890-01304
Piston pin puller
This tool is used to remove the piston pins.
90890-01312
Fuel level gauge
This tool is used to measure the fuel level in
the float chamber.
Radiator cap
tester
90890-01325
Adapter
90890-01352
Radiator cap tester
Adapter
These tools are used to check the cooling
system.
90890-01403
Steering nut wrench
Thistoolisusedtoloosenortightenthesteer-
ing stem ring nuts.
90890-01425
Damper rod holder
This tool is used to hold the damper rod as-
sembly when loosening or tightening the
damper rod assembly bolt.
90890-01471
Pivot shaft wrench
This tool is used to loosen or tighten the pivot
adjust bolt and engine mount adjust bolt.

1-9
SPECIAL TOOLS GEN
INFO
Tool No. Tool name/Function Illustration
90890-01426
Oil filter wrench
This tool is needed to loosen or tighten the oil
filter cartridge.
90890-01434
Rod holder
This tool is used to support the damper ad-
justing rod.
Rod puller
90890-01437
Rod puller
attachment
90890-01436
Rod puller
Rod puller attachment
These tools are used to pull up the front fork
damper rod.
90890-01441
Fork spring compressor
This tool is used to disassemble or assemble
the front fork legs.
Fork seal driver
90890-01376
Fork seal driver
attachment
90890-01374
Fork seal driver weight
Fork seal driver attachment
This tool is used to install the front fork’s oil
seal and dust seal.
90890-03008
Micrometer
This tool is used to measure the piston skirt
diameter.
90890-03017
Cylinder bore gauge (50~100mm)
This gauge is used to measure cylinder bore.
Vacuum gauge
90890-03094
Valve gauge
attachment
90890-03060
Vacuum gauge
Vacuum gauge attachment
This gauge is used to synchronize the carbu-
retors.
Compression
gauge
90890-03081
Adapter
90890-04136
Compression gauge
Adapter
These tools are used to measure engine
compression.
90890-03112
Pocket tester
This tool is used to check the electrical sys-
tem.

1-10
SPECIAL TOOLS GEN
INFO
Tool No. Tool name/Function Illustration
90793-80009
Engine tachometer
This tool is used to check engine speed.
90890-03141
Timing light
This tool is used to check the ignition timing.
Oil pressure
gauge
90890-03153
Adapter
90890-03139
Oil pressure gauge
Adapter
These tools are used to measure engine oil
pressure.
90890-04044
Piston ring compressor
This tool is used to compress piston rings
when installing the cylinder.
90890-03158
Carburetor angle driver
This tool is used to turn the pilot screw when
adjusting the engine idling speed.
Valve spring
compressor
90890-04019
Attachment
90890-04108
Valve spring compressor
Attachment
These tools are used to remove or install the
valve assemblies.
Middle driven shaft
bearing driver
90890-04058
Mechanical seal in-
staller
90890-04078
Middle driven shaft bearing driver
Mechanical seal installer
Thesetoolsareusedtoinstallthewaterpump
seal.
90890-04086
Clutch holding tool
This tool is used to hold the clutch boss
when removing or installing the clutch boss
nut.
90890-04111
Valve guide remover
Thistoolis used to removeorinstallthevalve
guides.

1-11
SPECIAL TOOLS GEN
INFO
Tool No. Tool name/Function Illustration
90890-04112
Valve guide installer
This tool is used to install the valve guides.
90890-04113
Valve guide reamer
This tool is used to rebore the new valve
guides.
90890-06754
Ignition checker
This tool is used to check the ignition system
components.
90890-85505
Yamaha bond No. 1215
Thisbondis usedtosealtwomatingsurfaces
(e.g., crankcase mating surfaces).

SPEC
CHAPTER 2.
SPECIFICATIONS
GENERAL SPECIFICATIONS 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ENGINE SPECIFICATIONS 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHASSIS SPECIFICATIONS 2-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ELECTRICAL SPECIFICATIONS 2-15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CONVERSION TABLE 2-18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TIGHTENING TORQUES 2-18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL TIGHTENING TORQUES 2-18. . . . . . . . . . . . . . . . . . . . . . . . . .
ENGINE TIGHTENING TORQUES 2-19. . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHASSIS TIGHTENING TORQUES 2-22. . . . . . . . . . . . . . . . . . . . . . . . . . .
LUBRICATION POINTS AND LUBRICANT TYPES 2-23. . . . . . . . . . . . . . . .
ENGINE LUBRICATION POINTS AND LUBRICANT TYPES 2-23. . . . .
CHASSIS LUBRICATION POINTS AND LUBRICANT TYPES 2-24. . . .
OIL FLOW DIAGRAMS 2-25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
COOLANT FLOW DIAGRAMS 2-29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CABLE ROUTING 2-33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-1
GENERAL SPECIFICATIONS SPEC
SPECIFICATIONS
GENERAL SPECIFICATIONS
Item Standard Limit
Dimensions
Overall length
Overall width
Overall height
Seat height
Wheelbase
Minimum ground clearance
Minimum turning radius
2025 mm (except for NOR, SWE, FIN, AUS NZL)
2075 mm (for NOR, SWE, FIN, AUS, NZL)
690 mm
1105 mm
820 mm
1380 mm
135 mm
3400 mm








Weight
Wet (with oil and a full fuel tank)
Dry (without oil and fuel)
Maximum load (total of cargo, rider,
passenger, and accessories)
188 kg
169 kg
375 kg


