2007

YZ85W1

5PA-28197-E0

SERVICE MANUAL

YZ85(W)

YZ85LW(W)

YZ85W1 / YZ85 (W) / YZ85LW (W)

SERVICE MANUAL

©2006 by Yamaha Motor Co., Ltd.

First edition, April 2006

All rights reserved.

Any reproduction or unauthorized use

without the written permission of

Yamaha Motor Co., Ltd.

is expressly prohibited.

EAS00000

EAS00002

NOTICE

This manual was produced by the Yamaha Motor Company, Ltd. primarily for use by Yamaha deal-

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

manual. Therefore, anyone who uses this book to perform maintenance and repairs on Yamaha

vehicles should have a basic understanding of mechanics and the techniques to repair these types

of vehicles.

Repair and maintenance work attempted by anyone without this knowledge is likely to render the

vehicle unsafe and unfit for use.

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

significant changes in specifications or procedures will be forwarded to all authorized Yamaha deal-

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

NOTE:

Designs and specifications are subject to change without notice.

EAS00004

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!

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

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

vehicle.

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

age to the vehicle.

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

WARNING

CAUTION:

NOTE:

EAS00007

HOW TO USE THIS MANUAL

This manual is intended as a handy, easy-to-read reference book for the mechanic. Comprehensive

explanations of all installation, removal, disassembly, assembly, repair and check procedures are

laid out with the individual steps in sequential order.

The manual is divided into chapters. An abbreviation and symbol in the upper right corner of

each page indicate the current chapter.

Refer to “SYMBOLS”.

Each chapter is divided into sections. The current section title is shown at the top of each page,

except in Chapter 3 (“PERIODIC CHECKS AND ADJUSTMENTS”), where the sub-section title(s)

appears.

Sub-section titles appear in smaller print than the section title.

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

each removal and disassembly section.

Numbers are given in the order of the jobs in the exploded diagram. A circled number indicates a

disassembly step.

Symbols indicate parts to be lubricated or replaced.

Refer to “SYMBOLS”.

A job instruction chart accompanies the exploded diagram, providing the order of jobs, names of

parts, notes in jobs, etc.

Jobs requiring more information (such as special tools and technical data) are described sequen-

tially.

EAS00008

SYMBOLS

The following symbols are not relevant to every

vehicle.

Symbols

to

indicate the subject of each

chapter.

General information

Specifications

Periodic checks and adjustments

Chassis

Engine

Cooling system

Carburetor(s)

Electrical system

Tuning

Troubleshooting

Symbols

to

indicate the following.

Serviceable with engine mounted

Filling fluid

Lubricant

Special tool

Tightening torque

Wear limit, clearance

Engine speed

Electrical data

Symbols

to

in the exploded diagrams

indicate the types of lubricants and lubrication

points.

Engine oil

Gear oil

Molybdenum-disulfide oil

Wheel-bearing grease

Lithium-soap- based grease

Molybdenum-disulfide grease

Symbols

to

in the exploded diagrams

indicate the following.

Apply locking agent (LOCTITE^®)

Replace the part with a new one.

EAS00010 TABLE OF CONTENTS

GENERAL INFORMATION

GEN

INFO 1

SPECIFICATIONS

SPEC 2

PERIODIC CHECKS AND

ADJUSTMENTS

CHK

ADJ 3

CHASSIS

CHAS 4

ENGINE

ENG 5

COOLING SYSTEM

COOL 6

CARBURETOR

CARB 7

ELECTRICAL SYSTEM

ELEC 8

TUNING

TUN 9

TROUBLESHOOTING

TRBL

SHTG 10

GEN

INFO

CHAPTER 1

GENERAL INFORMATION

VEHICLE 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

FUEL AND ENGINE MIXING OIL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

CHECKING THE CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

SPECIAL TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

GEN

INFO

1-1

EAS00014

GENERAL INFORMATION

VEHICLE IDENTIFICATION

EAS00017

VEHICLE IDENTIFICATION NUMBER

The vehicle identification number

is

stamped into the right side of the steering

head pipe.

EAS00018

MODEL LABEL

The model label

is affixed to the frame. This

information will be needed to order spare

parts.

VEHICLE IDENTIFICATION

GEN

INFO

1-2

EAS00020

IMPORTANT INFORMATION

PREPARATION FOR REMOVAL AND

DISASSEMBLY

1. Before removal and disassembly, remove

all dirt, mud, dust and foreign material.

2. Use only the proper tools and cleaning

equipment.

Refer to the “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 must always be reused or replaced as

an assembly.

4. During disassembly, clean all of the parts

and place them in trays in the order of dis-

assembly. This will speed up assembly and

allow for the correct installation of all parts.

5. Keep all parts away from any source of fire.

EAS00021

REPLACEMENT PARTS

Use only genuine Yamaha parts for all replace-

ments. Use oil and grease recommended by

Yamaha for all lubrication jobs. Other brands

may be similar in function and appearance, but

inferior in quality.

EAS00022

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.

lip

oil

lip

spring

grease

IMPORTANT INFORMATION

GEN

INFO

1-3

EAS00023

LOCK WASHERS / PLATES AND COTTER

PINS

After removal, replace all lock washers / plates

and cotter pins. After the bolt or nut has

been tightened to specification, bend the lock

tabs along a flat of the bolt or nut.

EAS00024

BEARINGS AND OIL SEALS

Install bearings and oil seals so that the manu-

facturer’s marks or numbers are visible. When

installing oil seals, lubricate the oil seal lips

with a light coat of lithium-soap-based grease.

Oil bearings liberally when installing, if appro-

priate.

Oil seal

CAUTION:

Do not spin the bearing with compressed

air because this will damage the bearing

surfaces.

Bearing

EAS00025

CIRCLIPS

Before reassembly, check all circlips carefully

and replace damaged or distorted circlips.

Always replace piston pin clips after one use.

When installing a circlip

, make sure the

sharp-edged corner

is positioned opposite

the thrust

that the circlip receives.

Shaft

IMPORTANT INFORMATION

GEN

INFO

1-4

FUEL AND ENGINE MIXING OIL

Mix oil with the gas at the ratio specified below.

Always use fresh, name-brand gasoline, and

mix the oil and gas the day of the race. Do not

use premix that is more than a few hours old.

NOTE:

NOTE:

If knocking or pinging occurs, use a different

brand of gasoline or higher octane grade.

CAUTION:

Never mix two types of oil in the same

batch; clotting of the oil could result. If you

wish to change oil types, be sure to drain

the fuel tank and the carburetor float bowl

of old premix prior to filling with the new

type.

Recommended fuel

Premium unleaded gasoline

only with a research octane

number of 95 or higher.

Fuel tank capacity

5.0 L (1.10 Imp gal, 1.32 US gal)

Mixing oil

Recommended oil

Yamalube “2-R”

(Yamalube racing 2-cycle oil)

Mixing ratio: 30 : 1

If unavailable, use an equivalent

type of oil.

YAMALUBE “2-R”

FUEL AND ENGINE MIXING OIL

GEN

INFO

1-5

EAS00026

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

several times.

3. Check:

• all connections

Loose connection → Connect properly.

NOTE:

NOTE:

If the pin

on the terminal is flattened, bend it

up.

4. Connect:

• lead

• coupler

• connector

NOTE:

NOTE:

Make sure all connections are tight.

5. Check:

• continuity

(with the pocket tester)

NOTE:

NOTE:

• 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.

Pocket tester

90890-03112, YU-3112-C

CHECKING THE CONNECTIONS

GEN

INFO

1-6

EAS00027

SPECIAL TOOLS

The following special tools are necessary for complete and accurate tune-up and assembly. Use

only the appropriate special tools as this will help prevent damage caused by the use of inappropri-

ate tools or improvised techniques. Special tools, part numbers or both may differ depending on the

country.

When placing an order, refer to the list provided below to avoid any mistakes.

NOTE:

• For U.S.A. and Canada, use part number starting with “YM-”, “YU-”, or “ACC-”.

• For others, use part number starting with “90890-”.

Tool No.

Tool name / Function

Illustration

90890-01135

YU-1135-A

Crankcase separating tool

This tool is used to split the crankcase as well

as remove the crankshaft from either case.

90890-01189

YM-1189

Flywheel puller

This tool is used to remove the flywheel

magneto.

90890-01235

YU-1235

Rotor holding tool

This tool is used when loosening or tightening

the flywheel magneto securing nut.

Dial gauge set

90890-01252

Dial gauge and

stand

YU-3097

YU-1256

Dial gauge and stand

Stand

These tools are used to check each part for

runout or bent.

90890-01268

Ringnut wrench

This tool is used to loosen and tighten the

exhaust and steering ringnut.

Crankshaft installing tool

For EUR, OCE

90890-01274

90890-01275

90890-01277

For U.S.A, CAN

YU-90050

YM-1277

Crankshaft installing tool

Crankshaft installing pot

Crankshaft installing bolt

Adapter (M10)

These tools are used to install the crankshaft.

90890-01304

YU-1304

Piston pin puller set

This tool is used to remove the piston pin.

SPECIAL TOOLS

GEN

INFO

1-7

Tool No.

Tool name / Function

Illustration

Radiator cap tester

90890-01325

YU-24460-01

Radiator cap

tester adapter

90890-01352

YU-33984

Radiator cap tester

Radiator cap tester adapter

These tools are used for checking the cooling

system.

90890-01403

YU-33975

Steering nut wrench

This tool is used when tighten the steering

ring nut to specification.

90890-01434

YM-01434

Rod holder

This tool is used to hold the fork spring.

Rod puller

90890-01437

YM-01437

Rod puller

attachment

90890-01436

YM-01436

Rod puller

Rod puller attachment (M10)

These tools are used to pull up the fork

damper rod.

90890-01442

YM-01442

Fork seal diver

This tool is used when install the fork oil seal.

90890-01454

YM-01454

Damper rod holder

Use this tool to remove and install the damper

rod.

90890-01495

YM-01495

Drive gear holder

This tool is used when removing or tightening

the primary drive gear securing nut.

90890-03112

YU-3112-C

Pocket tester

Use this tool to inspect the coil resistance,

output voltage and amperage.

90890-04086

YM-91042

Universal clutch holder

This tool is used to hold the clutch when

removing or installing the clutch boss

securing nut.

SPECIAL TOOLS

GEN

INFO

1-8

Tool No.

Tool name / Function

Illustration

90890-06754

YM-34487

Dynamic spark tester

Ignition checker

This instrument is necessary for checking the

ignition system components.

90890-85505

Yamaha bond No.1215

(Three Bond No.1215^®)

This sealant (Bond) is used for crankcase

mating surface, etc.

SPECIAL TOOLS