Page 20 of 506

EC0A0000
CONTENTS
CHAPTER 1
GENERAL INFORMATION
DESCRIPTION
........................................... 1-1
MACHINE IDENTIFICATION
..................... 1-2
IMPORTANT INFORMATION
.................... 1-3
CHECKING OF CONNECTION
................. 1-6
SPECIAL TOOLS
...................................... 1-7
CONTROL FUNCTIONS
............................ 1-9
FUEL AND ENGINE MIXING OIL
............ 1-12
STARTING AND BREAK-IN
.................... 1-13
TORQUE-CHECK POINTS
...................... 1-16
CLEANING AND STORAGE
................... 1-17
CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATIONS
................... 2-1
MAINTENANCE SPECIFICATIONS
.......... 2-4
ENGINE
................................................... 2-4
CHASSIS
................................................. 2-8
YZ85
..................................................... 2-8
YZ85LW
.............................................. 2-10
ELECTRICAL
........................................ 2-14
GENERAL TORQUE
SPECIFICATIONS
................................... 2-15
DEFINITION OF UNITS
........................... 2-15
CABLE ROUTING DIAGRAM
................. 2-16
Page 39 of 506

GEN
INFO
1 - 8
SPECIAL TOOLS
YU-33975, 90890-01403 Steering nut wrench
This tool is used when tighten the steering ring nut to
specification.YU-33975 90890-01403
YM-01434, 90890-01434 Rod holder
This tool is used to hold the fork spring.YM-01434 90890-01434
YM-01437, 90890-01437
90890-01436Rod puller
Rod puller attachment (M10)
These tools are used to pull up the fork damper rod.YM-01437 90890-01437
90890-01436
YM-01442, 90890-01442 Fork seal driver
This tool is used when install the fork oil seal.YM-01442 90890-01442
YM-01454, 90890-01454 Damper rod holder
Use this tool to remove and install the damper rod.YM-01454 90890-01454
YU-3112-C, 90890-03112 Pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.YU-3112-C 90890-03112
YM-91042, 90890-04086 Clutch holding tool
This tool is used to hold the clutch when removing or
installing the clutch boss securing nut.YM-91042 90890-04086
YM-34487
90890-06754Dynamic spark tester
Ignition checker
This instrument is necessary for checking the ignition
system components.YM-34487 90890-06754
ACC-QUICK-GS-KT
90890-85505Quick gasket
YAMAHA Bond No. 1215
This sealant (Bond) is used for crankcase mating sur-
face, etc.ACC-QUICK-GS-KT 90890-85505
YM-01495, 90890-01495 Drive gear holder
This tool is used when removing or tightening the pri-
mary drive gear securing nut.YM-01495 90890-01495
Part number Tool name/How to use Illustration
5PA10360
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3 - 23
INSP
ADJ
DRIVE CHAIN SLACK ADJUSTMENT
5. Install:
Drive chain 1
Joint 2
Master link clip 3
CAUTION:
Be sure to install the master link clip to the
direction as shown.
aTurning direction5PA30530
6. Lubricate:
Drive chain
Drive chain lubricant:
SAE 10W-30 motor oil or suit-
able chain lubricants
5PA30540
EC36A060
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the suit-
able stand under the engine.
2. Check:
Drive chain slack
a
In the center between the drive axle and
rear wheel axle.
Out of specification → Adjust.
NOTE:
Before checking and/or adjusting, rotate the
rear wheel through several revolutions and
check the slack several times to find the tight-
est point. Check and/or adjust chain slack with
rear wheel in this “tight chain” position.
Drive chain slack:
35 ~ 45 mm (1.4 ~ 1.8 in)
5PA30550
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5 - 36
CHAS
19. Wait ten minutes until the air bubbles have
been removed from the front fork, and the
oil has dispense evenly in system before
setting recommended oil level.
NOTE:
Fill with the fork oil up to the top end of the
outer tube, or the fork oil will not spread over to
every part of the front forks, thus making it
impossible to obtain the correct level.
Be sure to fill with the fork oil up to the top of
the outer tube and bleed the front forks.
20. Measure:
Oil level (left and right) a
Out of specification → Adjust.
NOTE:
Be sure to install the spring guide 2 when
checking the oil level.
WARNING
Never fail to make the oil level adjustment
between the maximum and minimum level
and always adjust each front fork to the
same setting. Uneven adjustment can
cause poor handling and loss of stability.
Standard oil level:
90 mm (3.54 in)
Extent of adjustment:
80 ~ 120 mm (3.15 ~ 4.72 in)
From top of outer tube with
inner tube and damper rod 1
fully compressed without
spring.
5PA51120
FRONT FORK
Page 452 of 506
6 - 2
–+ELECIGNITION SYSTEM
EC620000
IGNITION SYSTEM
INSPECTION STEPS
Use the following steps for checking the possibility of the malfunctioning engine being attributable to
ignition system failure and for checking the spark plug which will not spark.
*marked: Only when the ignition checker is used.
NOTE:
Remove the following parts before inspection.
1) Seat
2) Fuel tank
Use the following special tools in this inspection.
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754Pocket tester:
YU-3112-C/90890-03112
Spark gap test*Clean or replace
spark plug.
Check entire ignition
system for connection.Repair or replace.
Check engine stop switch. Replace.
Check ignition coil. Primary coil Replace.
Secondary coil Replace.
Check spark plug cap. Replace.
Check CDI magneto. Pickup coil Replace.
Charging coil Replace.
Replace CDI unit.
No spark
OK
OK
OK
OK
OK
Spark
No good
No good
No good
No good
No good
No good
No good
Page 480 of 506

7 - 9
TUNSETTING
Change of the heat range of spark plugs
Judging from the discoloration of spark plugs,
if they are found improper, it can be corrected
by the following two methods; changing carbu-
retor settings and changing the heat range of
spark plug.
In principle, it is advisable to first use spark
plugs of standard heat range, and judging
from the discoloration of spark plugs, adjust
carburetor settings.
If the calibration No. of the main jet must be
changed by ±30, it is advisable to change the
heat range of spark plugs and newly select
the proper main jet.
NOTE:
When checking the discoloration of spark
plugs, be sure to stop the engine immedi-
ately after a run and check.
Avoid racing.
When changing the heat range of spark
plugs, never attempt to change it more than
±1 rank.
When using a spark plug other than stan-
dard, check its heat range against the stan-
dard and check that it is a resistance type.
Note that even if the discoloration seems
proper, it may slightly vary with the spark
plug maker and oil in use.Standard spark plugBR10EG/NGK
(resistance type)
5PA70110