brake YAMAHA YZ85 2002 Owner's Manual

3 - 21
INSP
ADJ
BRAKE FLUID LEVEL INSPECTION
3. Inspect:
lBrake fluid level
Refer to “BRAKE FLUID LEVEL INSPEC-
TION” section.
4. Check:
lBrake pedal operation
A softy or spongy feeling ® Bleed brake
system.
Refer to “BRAKE SYSTEM AIR BLEED-
ING” section.
BRAKE FLUID LEVEL INSPECTION
1. Place the brake master cylinder (reservoir
tank) so that its top is in a horizontal posi-
tion.
2. Inspect:
lBrake fluid level
Fluid at lower level a ® Fill up.
ÈFront
ÉRear
WARNING
lUse only designated quality brake fluid to
avoid poor brake performance.
lRefill with same type and brand of brake
fluid; mixing fluids could result in poor
brake performance.
lBe sure that water or other contaminants
do not enter master cylinder when refill-
ing.
lClean up spilled fluid immediately to
avoid erosion of painted surfaces or plas-
tic parts.
lInstall the brake caliper 0 and tighten the
pad pins A.
T R..
Bolt (brake caliper):
23 Nm (2.3 m • kg, 17 ft • lb)
Pad pin:
18 Nm (1.8 m • kg, 13 ft • lb)
NOTE:
Apply the LOCTITE® on the bolt (brake cali-
per rear side).
Recommended brake fluid:
DOT #4
5PA30460
È
5PA30470
É

3 - 24
INSP
ADJFRONT FORK INSPECTION/
FRONT FORK OIL SEAL AND DUST SEAL CLEANING
3. Adjust:
lDrive chain slack
Drive chain slack adjustment steps:
lLoosen the axle nut 1 and locknuts 2.
lAdjust chain slack by turning the adjusters 3.
To tighten
® Turn adjuster
3 clockwise.
To loosen
® Turn adjuster
3 counter-
clockwise and push wheel forward.
lTurn each adjuster exactly the same
amount to maintain correct axle alignment.
(There are marks a on each side of chain
puller alignment.)
NOTE:
Turn the adjuster so that the chain is in line
with the sprocket, as viewed from the rear.
CAUTION:
Too small chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.
lTighten the axle nut while pushing down
the drive chain.
T R..
Axle nut:
110 Nm (11.0 m • kg, 80 ft • lb)
lTighten the locknuts.
5PA30560
EC36C000
FRONT FORK INSPECTION
1. Inspect:
lFront fork smooth action
Operate the front brake and stroke the front
fork.
Unsmooth action/oil leakage ® Repair or
replace.
5PA30570
EC36D001
FRONT FORK OIL SEAL AND DUST SEAL
CLEANING
1. Remove:
lProtector 1
lDust seal 2
NOTE:
Use a thin screw driver, and be careful not to
damage the inner fork tube and dust seal.5PA30580

3 - 34
INSP
ADJ
LUBRICATION
LUBRICATION
To ensure smooth operation of all compo-
nents, lubricate your machine during setup,
after break-in, and after every race.
1All control cable
2Clutch lever pivot
3Shift pedal pivot
4Footrest pivot
5Throttle-to-handlebar contact
6Drive chain
7Tube guide cable winding portion
8Throttle cable end
9Clutch cable endÈUse Yamaha cable lube or equivalent on these
areas.
ÉUse SAE 10W-30 motor oil or suitable chain
lubricants.
ÊLubricate the following areas with high quality,
lightweight lithium-soap base grease.
CAUTION:
Wipe off any excess grease, and avoid get-
ting grease on the brake discs.
AAA
AAB
CC
5PA307705PA307805PA30790
5PA308005PA308105PA30820
5PA308005PA30840

4 - 33
ENGKICK SHAFT, SHIFT SHAFT AND PRIMARY DRIVE GEAR
KICK SHAFT, SHIFT SHAFT AND PRIMARY DRIVE GEAR
PRIMARY DRIVE GEAR
5PA40960
Extent of removal:
1 Primary drive gear removal
Extent of removal Order Part name Q’ty Remarks
PRIMARY DRIVE GEAR
REMOVAL
Drain the transmission oil. Refer to “TRANSMISSION OIL
REPLACEMENT” section in the CHAP-
TER 3.
Brake pedal
Radiator hose 2 Disconnect at water pump side.
1 Kickstarter crank 1
2 Right crankcase cover 1
3 Nut (primary drive gear) 1 Only loosening.
Refer to “REMOVAL POINTS”.
4 Primary driven gear 1 Refer to “CLUTCH AND PRIMARY
DRIVEN GEAR” section.
5 Primary drive gear 1
1

4 - 51
ENG
EC4M3000
REMOVAL POINTS
EC4F3100
Drive sprocket
1. Remove:
lNut (drive sprocket) 1
lLock washer 2
NOTE:
lStraighten the lock washer tab.
lLoosen the nut while applying the rear brake.5PA41510
2. Remove:
lDrive sprocket 1
lDrive chain 2
NOTE:
Remove the drive sprocket together with the
drive chain.
5PA41520
EC4M3301
Engine removal
1. Remove:
lPivot shaft 1
NOTE:
If the pivot shaft is pulled all the way out, the
swingarm will come loose. If possible, insert a
shaft of similar diameter into the other side of
the swingarm to support it.5PA41530
2. Remove:
lEngine 1
From right side.
NOTE:
Make sure that the couplers, hoses and cables
are disconnected.
5PA41540
ENGINE REMOVAL

4 - 52
ENG
EC4M5000
ASSEMBLY AND INSTALLATION
Engine installation
1. Install:
lEngine 1
Install the engine from right side.
lPivot shaft 2
lEngine mounting bolt (front) 3
lEngine mounting bolt (lower) 4
NOTE:
Apply the molybdenum disulfide grease on the
pivot shaft.
5PA41550
T R..63 Nm (6.3 m · kg, 45 ft · lb)
T R..69 Nm (6.9 m · kg, 50 ft · lb)
T R..69 Nm (6.9 m · kg, 50 ft · lb)
Drive sprocket
1. Install:
lDrive sprocket 1
lDrive chain 2
NOTE:
Install the drive sprocket together with the
drive chain.
5PA41560
2. Install:
lLock washer 1
lNut (drive sprocket) 2
NOTE:
Tighten the nut while applying the rear brake.
3. Bend the lock washer tab to lock the nut.
5PA41570
T R..60 Nm (6.0 m · kg, 43 ft · lb)
4. Install:
lGasket (left crankcase cover)
lLeft crankcase cover 1
lScrew (left crankcase cover) 2
NOTE:
Tighten the screws in stage, using a crisscross
pattern.
5PA41580
T R..5 Nm (0.5 m · kg, 3.6 ft · lb)
ENGINE REMOVAL

5 - 1
CHAS
EC500000
CHASSIS
EC590000
FRONT WHEEL AND REAR WHEEL
EC598000
FRONT WHEEL
FRONT WHEEL AND REAR WHEEL
Extent of removal:
1 Front wheel removal
2 Wheel bearing removal
3 Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is no
danger of it falling over.
1 Nut (front wheel axle) 1
2 Front wheel axle 1
3 Front wheel 1
4 Collar 2
5 Oil seal 2
6 Bearing 2 Refer to “REMOVAL POINTS”.
7 Brake disc 1
2
31
3
5PA50010




5

5 - 2
CHAS
EC598100
REAR WHEEL
5PA50020
Extent of removal:
1 Rear wheel removal
2 Wheel bearing removal
3 Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is no
danger of it falling over.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Drive chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Rear wheel sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10Brake disc
1
2
31
3
FRONT WHEEL AND REAR WHEEL

5 - 4
CHAS
EC514200
Wheel axle
1. Measure:
lWheel axle 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 axle.
Wheel axle bending limit:
0.5 mm (0.020 in)
5PA50070
Brake disc
1. Measure:
lBrake disc deflection
Use the dial gauge 1.
Out of specification ® Inspect wheel
runout.
If wheel runout is in good condition, replace
the brake disc.
2. Measure:
lBrake disc thickness a
Out of limit ® Replace.
Brake disc deflection limit:
0.15 mm (0.006 in)
Brake disc thickness:
3.0 mm (0.12 in)
: 2.5 mm (0.10 in)
5PA50080
FRONT WHEEL AND REAR WHEEL

5 - 5
CHAS
EC595000
ASSEMBLY AND INSTALLATION
Front wheel
1. Install:
lBearing (left) 1
lSpacer 2
lBearing (right) 3
lOil seal 4
NOTE:
lApply the lithium soap base grease on the
bearing and oil seal lip when installing.
lUse a socket that matches the outside diam-
eter of the race of the bearing.
lLeft side of bearing shall be installed first.
lInstall the oil seal with its manufacture’s
marks or numbers facing outward.
CAUTION:
Do not strike the inner race of the bearing.
Contact should be made only with the outer
race.
2. Install:
lBrake disc 1
lBolt (brake disc) 2
5PA50090
5PA50100
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
3. Install:
lCollar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
5PA50110
4. Install:
lWheel
NOTE:
Install the brake disc 1 between the brake
pads 2 correctly.
5PA50120
FRONT WHEEL AND REAR WHEEL