2002 YAMAHA YZ85 length

3 - 22
INSP
ADJ
SPROCKETS INSPECTION
1. Inspect:
lSprocket teeth a
Excessive wear ® Replace.
NOTE:
Replace the drive sprocket, rear wheel
sprocket and drive chain as a set.
5PA30480
EC369002
DRIVE CHAIN INSPECTION
1. Remove:
lMaster link clip
lJoint 1
lDrive chain 2
5PA30490
2. Clean:
lDrive chain
Place it in kerosene, and brush off as much
dirt as possible. Then remove the chain
from the kerosene and dry the chain.
5PA30500
3. Measure:
lDrive chain length (10 links) a
Out of limit ® Replace.
Drive chain length (10 links):
: 122.1 mm (4.81 in)
5PA30510
4. Check:
lDrive chain stiffness a
Clean and oil the chain and hold as illus-
trated.
Stiff ® Replace drive chain.
5PA30520
SPROCKETS INSPECTION/
DRIVE CHAIN INSPECTION

3 - 28
INSP
ADJREAR SHOCK ABSORBER SPRING PRELOAD
ADJUSTMENT
REAR SHOCK ABSORBER SPRING
PRELOAD ADJUSTMENT
1. Elevate the rear wheel by placing the suit-
able stand under the engine.
2. Remove:
lRear frame
3. Loosen:
lLocknut 1
4. Adjust:
lSpring preload
By turning the adjuster 2.
* For EUROPE
NOTE:
lBe sure to remove all dirt and mud from
around the locknut and adjuster before
adjustment.
lThe length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjuster.
CAUTION:
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
5. Tighten:
lLocknut
6. Install:
lRear frame (upper)
lRear frame (lower) Stiffer
®Increase the spring preload.
(Turn the adjuster
2 in.)
Softer
®Decrease the spring preload.
(Turn the adjuster
2 out.)
Spring length (installed)
a:
YZ85: 215 mm (8.46 in)
*212 mm (8.35 in)
YZ85LW: 207 mm (8.15 in)
*212 mm (8.35 in)
Extent of adjustment:
202.5 ~ 218.5 mm
(7.97 ~ 8.60 in)
5PA30630
5PA30640
T R..26 Nm (2.6 m · kg, 19 ft · lb)
T R..16 Nm (1.6 m · kg, 11 ft · lb)

4 - 28
ENG
REMOVAL POINTS
Clutch boss
1. Remove:
lNut (clutch boss) 1
lConical washer 2
lClutch boss 3
NOTE:
Use the clutch holding tool 4 to hold the clutch
boss.
ÈFor USA and CDN
ÉExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-04086
5PA40740
È€É
5PA40750
EC494000
INSPECTION
EC484100
Clutch housing and boss
1. Inspect:
lClutch housing 1
Cracks/wear/damage ® Replace.
lClutch boss 2
Scoring/wear/damage ® Replace.
5PA40760
EC484201
Primary driven gear
1. Check:
lCircumferential play
Free play exists ® Replace.
lGear teeth
a
Wear/damage ® Replace.
5PA40770
Clutch spring
1. Measure:
lClutch spring free length
a
Out of limit ® Replace springs as a set.
Clutch spring free length:
34.0 mm (1.34 in)
: 32.0 mm (1.26 in)
5PA40780
CLUTCH AND PRIMARY DRIVEN GEAR

5 - 31
CHAS
EC554200
Base valve
1. Inspect:
lValve assembly 1
Wear/damage ® Replace.
lO-ring 2
Damage ® Replace.
5PA50900
EC554400
Fork spring
1. Measure:
lFork spring free length a
Out of specification ® Replace.
EC554502
Inner tube
1. Inspect:
lInner tube surface a
Score marks ® Repair or replace.
Use #1,000 grit wet sandpaper.
Damaged oil lock piece ® Replace.
lInner tube bends
Out of specification ® Replace.
Use the dial gauge 1.
NOTE:
The bending value is shown by one half of the
dial gauge reading.
WARNING
Do not attempt to straighten a bent inner
tube as this may dangerously weaken the
tube.
EC554600
Outer tube
1. Inspect:
lOuter tube 1
Score marks/wear/damage ® Replace.
Fork spring free length:
430 mm (16.9 in)
: 425 mm (16.7 in)
Inner tube bending limit:
0.2 mm (0.008 in)
5PA50910
5PA50920
5PA50930
FRONT FORK

5 - 62
CHAS
3. Adjust:
lSpring length (installed) a
* For EUROPE
NOTE:
The length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjuster.
CAUTION:
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
4. Tighten:
lLocknut 1
Spring length (installed) a:
YZ85: 215 mm (8.46 in)
*212 mm (8.35 in)
YZ85LW: 207 mm (8.15 in)
*212 mm (8.35 in)
Extent of adjustment
202.5 ~ 218.5 mm
(7.97 ~ 8.60 in)
5PA51920
5PA51930
Rear shock absorber
1. Install:
lRear shock absorber
2. Install:
lBolt (rear shock absorber-frame) 1
lWasher 2
lNut (rear shock absorber-frame) 3
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
3. Install:
lWasher 1
lBolt (rear shock absorber-relay arm) 2
NOTE:
lApply the molybdenum disulfide grease on
the bolt.
lInsert the bolt from left side.
5PA51940
T R..36 Nm (3.6 m · kg, 25 ft · lb)
5PA51950
T R..36 Nm (3.6 m · kg, 25 ft · lb)
REAR SHOCK ABSORBER

7 - 14
TUN
Front fork setting parts
lFront fork spring 1
YZ85
YZ85LW
NOTE:
The I.D. mark (slits) a is proved on the end of
the spring.TYPESPRING
RATESPRING
PART NUMBERI.D.
MARK
(slits)
SOFT 0.280 4ES-23141-50 I
STD 0.290 4ES-23141-40 –
STIFF 0.300 4ES-23141-60 II
TYPESPRING
RATESPRING
PART NUMBERI.D.
MARK
(slits)
SOFT 0.290 4ES-23141-40 –
STD 0.300 4LB-23141-10 –
STIFF 0.310 4ES-23141-70 III
5PA70150
EC72B000
Rear suspension setting
The rear suspension setting should be made
depending on the rider’s feeling of an actual
run and the circuit conditions.
The rear suspension setting includes the fol-
lowing two factors:
1. Setting of spring preload
lChange the set length of the spring.
lChange the spring.
2. Setting of damping force
lChange the rebound damping.
lChange the compression damping.
SETTING

7 - 15
TUNSETTING
EC72C001
Choosing set length
1. Place a stand or block under the engine to
put the rear wheel above the floor, and
measure the length a between the rear
wheel axle center and the rear fender hold-
ing bolt.
5PA70160
2. Remove the stand or block from the engine
and with a rider astride the seat, measure
the sunken length b between the rear
wheel axle center and the rear fender hold-
ing bolt.
5PA70170
3. Loosen the locknut 1 and make adjust-
ment by turning the spring adjuster 2 to
achieve the standard figure from the sub-
traction of the length b from the length a.
Standard figure:
75 ~ 85 mm (3.0 ~ 3.3 in)
5PA70180
NOTE:
lIf the machine is new and after it is broken in,
the same set length of the spring may
change because of the initial fatigue, etc. of
the spring. Therefore, be sure to make re-
evaluation.
lIf the standard figure cannot be achieved by
adjusting the spring adjuster and changing
the spring set length, replace the spring with
an optional one and make re-adjustment.

7 - 16
TUN
Setting of spring after replacement
After replacement, be sure to adjust the spring
to the set length [sunken length 75 ~ 85 mm
(3.0 ~ 3.3 in)] and set it.
1. Use of soft spring
lSet the soft spring for less rebound damp-
ing to compensate for its less spring load.
Run with the rebound damping adjuster
one or two clicks on the softer side and
readjust it to suit your preference.
2. Use of stiff spring
lSet the soft spring for more rebound damp-
ing to compensate for its greater spring
load. Run with the rebound damping
adjuster one or two clicks on the stiffer side
and readjust it to suit your preference.
*Adjusting the rebound damping will be fol-
lowed more or less by a change in the com-
pression damping. For correction, turn the
compression damping adjuster on the
softer side.
CAUTION:
When using a rear shock absorber other
than currently installed, use the one whose
overall length a does not exceed the stan-
dard as it may result in faulty performance.
Never use one whose overall length is
greater than standard.
ÈCoverage of spring by weight
ÉRider weight
1Soft
2Standard
3Stiff
Length a of standard shock:
403.5 mm (15.89 in)
5PA70190
5PA70140
SETTING