Yamaha YFM4FAR User manual

YFM4FAR
YFM400FAR
5TE2-AE1
SERVICE MANUAL

YFM4FAR/YFM400FAR
SERVICE MANUAL
©2002 by Yamaha Motor Co., Ltd.
First edition, April 2002
All rights reserved.
Any reproduction or unauthorized use
without the written permission of
Yamaha Motor Co., Ltd.
is expressly prohibited.

EB001000
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
significant changes in specifications or procedures will be forwarded to all authorized Yamaha
dealers and will appear in future editions of this manual where applicable.
N
OTE:
Designs and specifications are subject to change without notice.
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 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 procedures easier or clearer.
WARNING
CAUTION:
NOTE:

EB002000
HOW TO USE THIS MANUAL
MANUAL ORGANIZATION
This manual consists of chapters for the main categories of subjects. (See “Illustrated 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
accompanied 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.

EB003000
ILLUSTRATED SYMBOLS
Illustrated symbols 1to 0are printed on the
top right of each page and indicate the subject
of each chapter.
1General information
2Specifications
3Periodic checks and adjustments
4Engine
5Cooling system
6Carburetion
7Drive train
8Chassis
9Electrical
0Troubleshooting
Illustrated symbols Ato Hare used to identify
the specifications appearing in the text.
ACan be serviced with engine mounted
BFilling fluid
CLubricant
DSpecial tool
ETorque
FWear limit, clearance
GEngine speed
HΩ, V, A
Illustrated symbols Ito Nin the exploded
diagrams indicate the types of lubricants and
lubrication points.
IApply engine oil
JApply gear oil
KApply molybdenum disulfide oil
LApply wheel bearing grease
MApply lithium-soap-based grease
NApply molybdenum disulfide grease
Illustrated symbols Oto Pin the exploded
diagrams indicate where to apply a locking
agent Oand when to install a new part P.
OApply the locking agent (LOCTITE®)
PReplace
12
34
56
78
90
AB
CD
EF
GH
IJK
LMN
OP
GEN
INFO SPEC
CHK
ADJ ENG
COOL CARB
DRIV
CHAS
–+
ELEC TRBL
SHTG
T
R
.
.
EGM
BLS M
LT New

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
CARBURETION CARB 6
DRIVE TRAIN DRIV 7
CHASSIS CHAS 8
ELECTRICAL ELEC 9
TROUBLESHOOTING TRBL
SHTG
10
–+

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 PROCEDURES ............................... 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 OF CONNECTIONS ................................................................. 1-4
SPECIAL TOOLS ......................................................................................... 1-5

GEN
INFO

1 - 1
GEN
INFO
MACHINE IDENTIFICATION
GENERAL INFORMATION
MACHINE IDENTIFICATION
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number 1is
stamped into the left side of the frame.
MODEL LABEL
The model label 1is affixed to the frame. This
information will be needed to order spare
parts.

1 - 2
GEN
INFO
EB101000
IMPORTANT INFORMATION
PREPARATION FOR REMOVAL
PROCEDURES
1.Remove all dirt, mud, dust and foreign
material before removal and disassembly.
2.Use proper tools and cleaning equipment.
Refer to the “SPECIAL TOOLS” section.
3.When disassembling the machine, always
keep mated parts together. This includes
gears, cylinder, piston and other parts that
have been “mated” through normal wear.
Mated parts must always be reused or
replaced as an assembly.
4.During machine disassembly, clean all parts
and place them in trays in the order of
disassembly. This will speed up assembly
and allow for the correct installation of all
parts.
5.Keep all parts away from any source of fire.
EB101010
REPLACEMENT PARTS
1.Use only genuine Yamaha parts for all
replacements. Use oil and grease
recommended by Yamaha for all lubrication
jobs. Other brands may be similar in function
and appearance, but inferior in quality.
EB101020
GASKETS, OIL SEALS AND O-RINGS
1.Replace all gaskets, seals and O-rings when
overhauling the engine. All gasket surfaces,
oil seal lips and O-rings must be cleaned.
2.Properly oil all mating parts and bearings
during reassembly. Apply grease to the oil
seal lips.
IMPORTANT INFORMATION

1 - 3
GEN
INFO
EB101030
LOCK WASHERS/PLATES AND COTTER
PINS
1.Replace all lock washers/plates 1and cotter
pins after removal. Bend lock tabs along the
bolt or nut flats after the bolt or nut has been
tightened to specification.
EB101040
BEARINGS AND OIL SEALS
1.Install bearings and oil seals so that the
manufacturer’s marks or numbers are visible.
When installing oil seals, apply a light
coating of lightweight lithium base grease to
the seal lips. Oil bearings liberally when
installing, if appropriate.
1Oil seal
CAUTION:
Do not use compressed air to spin the
bearings dry. This will damage the bearing
surfaces.
1Bearing
EB101050
CIRCLIPS
1.Check all circlips carefully before
reassembly. Always replace piston pin clips
after one use. Replace distorted circlips.
When installing a circlip 1, make sure that
the sharp-edged corner 2is positioned
opposite the thrust 3it receives. See
sectional view.
4Shaft
IMPORTANT INFORMATION

1 - 4
GEN
INFO
CHECKING OF CONNECTIONS
EB801000
CHECKING OF CONNECTIONS
Check the connectors for stains, rust,
moisture, etc.
1.Disconnect:
●Connector
2.Check:
●Connector
Moisture →Dry each terminal with an air
blower.
Stains/rust →Connect and disconnect the
terminals several times.
3.Check:
●Connector leads
Looseness →Bend up the pin 1and
connect the terminals.
4.Connect:
●Connector terminals
N
OTE:
The two terminals “click”together.
5.Check:
●Continuity (using a pocket tester)
N
OTE:
●If there is no continuity, clean the terminals.
●When checking the wire harness be sure to
perform steps 1 to 3.
●As a quick remedy, use a contact revitalizer
available at most part stores.
●Check the connector with a pocket tester as
shown.

GEN
INFO
1 - 5
SPECIAL TOOLS
EB102001
SPECIAL TOOLS
The following special tools are necessary for complete and accurate tune-up and assembly. Use
only the appropriate special tools; this will help prevent damage caused by the use of inappropriate
tools or improvised techniques. Special tools may differ by shape and part number from country to
country. In such a case, two types are provided.
When placing an order, refer to the list provided below to avoid any mistakes.
For US and CDN
P/N. YM-, YU-, YS-, YK-, ACC-
Except for US and CDN
P/N. 90890-
Tool No. Tool name/How to use Illustration
Bolt
90890-01083
Weight
90890-01084
Set
YU-01083-A
Slide hammer bolt (M6)/weight/set
These tools are used to remove the
rocker arm shafts.
90890-01135
YU-01135-A
Crankcase separating tool
This tool is used to separate the
crankcase.
90890-01225
YM-01225-A
Valve guide remover (7.0 mm)
This tool is needed to remove and
install the valve guides.
90890-04017
YM-04017
Valve guide installer (7.0 mm)
This tool is needed to install the valve
guides.
90890-01227
YM-01227
Valve guide reamer (7.0 mm)
This tool is needed to rebore the new
valve guides.
90890-01235
YU-01235
Rotor holding tool
This tool is needed to hold the starter
pulley when removing/installing the
starter pulley bolt or camshaft
sprocket bolt.
90890-04088
Bolt
90890-01275
Buffer boss installer set
Crankshaft installer bolt
These tools are used to install the
crankshaft.

GEN
INFO
1 - 6
SPECIAL TOOLS
YU-90050
Crankshaft installer set
These tools are used to install the
crankshaft.
Adapter
YM-33279
Spacer
90890-04060
YM-90070-A
Adapter #11
Spacer (crankshaft)
These tools are used to install the
crankshaft.
90890-01304
YU-01304
Piston pin puller set
This tool is used to remove the piston
pin.
90890-01311
YU-08035
Tappet adjusting tool
This tool is necessary for adjusting
the valve clearance.
90890-01312
YM-01312-A
Fuel level gauge
This gauge is used to measure the
fuel level in the float chamber.
90890-01325
YU-24460-01
Radiator cap tester
This tool is used to check the cooling
systems.
90890-01352
YU-33984
Adapter
This tool is used to check the cooling
systems.
90890-01348
YM-01348
Locknut wrench
This tool is needed when removing or
installing the secondary sheave
spring.
90890-04134
YM-04134
Sheave spring compressor
This tool is needed when removing or
installing the secondary sheave
spring.
Tool No. Tool name/How to use Illustration

GEN
INFO
1 - 7
SPECIAL TOOLS
90890-04135
YM-04135
Sheave fixed block
This tool is needed when removing or
installing the secondary sheave
spring.
90890-01404
YM-01404
Flywheel puller
These tools are needed to remove
the rotor.
90890-01327
YM-01327
Damper rod holder (30 mm)
This tool is needed to loosen and
tighten the steering stem bearing
retainers.
90890-01426
YU-38411
Oil filter wrench
This tool is needed to loosen or
tighten the oil filter cartridge.
90890-01430
YM-38404
Ring nut wrench
This tool is needed to removing and
installing the middle driven shaft
bearing retainers.
90890-01467
YM-01467
90890-01475
YM-01475
Gear lash measurement tool
This tool is used to measure the gear
lash.
90890-01474
YM-01474
Ball joint remover/installer set
This tool is used to remove and install
the ball joints.
YM-01477
Ball joint remover/installer attachment
set
This tool is used to remove and install
the ball joints.
90890-01701
YS-01880-A
Sheave holder
This tool is needed to hold the
primary sheave when removing or
installing the sheave bolts.
Tool No. Tool name/How to use Illustration

GEN
INFO
1 - 8
SPECIAL TOOLS
Compression gauge
90890-03081
YU-33223
Adapter
90890-04082
YU-33223-3
Compression gauge
Adapter
These tools are needed to measure
engine compression.
90890-03112
YU-03112-C
Pocket tester
This instrument is needed for
checking the electrical system.
90890-03113
Engine tachometer
This tool is needed for observing
engine rpm.
YU-8036-B
Inductive self-powered tachometer
This tool is needed for observing
engine rpm.
90890-03141
YM-33277-A
Timing light
This tool is necessary for checking
ignition timing.
90890-04019
YM-04019
Valve spring compressor
This tool is needed to remove and
install the valve assemblies.
Middle driven shaft
bearing driver
90890-04058
YM-04058-1
Mechanical seal installer
90890-04078
YM-33221
Middle driven shaft bearing driver
Mechanical seal installer
These tools are used to install the
water pump seals.
90890-04050
YM-04050
Bearing retainer wrench
This tool is needed when removing or
installing the final drive shaft bearing
retainers.
90890-04062
YM-04062
Universal joint holder
This tool is needed when removing or
installing the universal joint yoke nuts.
Tool No. Tool name/How to use Illustration

GEN
INFO
1 - 9
SPECIAL TOOLS
90890-04086
YM-91042
Clutch holding tool
This tool is needed to hold the clutch
carrier when removing or installing
the carrier nut.
90890-04128
YM-04128
Bearing retainer wrench
This tool is needed when removing or
installing the middle driven pinion
gear bearing retainers.
90890-04129
YM-04129
Pinion gear fix clamp
This tool is used to hold the shift cam.
90890-06754
Ignition checker
This instrument is necessary for
checking the ignition system
components.
YM-34487
Dynamic spark tester
This instrument is necessary for
checking the ignition system
components.
Bond
90890-85505
Sealant
ACC-11001-05-01
Yamaha bond No. 1215
Sealant (Quick Gasket®)
This sealant (bond) is used on
crankcase mating surfaces, etc.
Tool No. Tool name/How to use Illustration