2002 YAMAHA YZ85 brake

SPEC
2 - 12
MAINTENANCE SPECIFICATIONS
NOTE:
1. First, tighten the steering nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the steering
nut wrench, then loosen the steering nut one turn.
2. Retighten the steering nut 4 Nm (0.4 m • kg, 2.9 ft • lb).Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Upper bracket and outer tube M8 ´ 1.25 2 22 2.2 16
Lower bracket and outer tube M8 ´ 1.25 4 20 2.0 14
Upper bracket and steering stem M22 ´ 1.0 1 115 11.5 85
Handlebar holder and upper bracket M8 ´ 1.25 4 27 2.7 19
Steering stem and steering ring nut M25 ´ 1.0 1 Refer to NOTE.
Front fork and front fork cap bolt M40 ´ 1.0 2 28 2.8 20
Front fork and base valve M22 ´ 1.0 2 55 5.5 40
Front fork cap bolt and damper rod M10 ´ 1.0 2 15 1.5 11
Front fork bleed screw and front fork cap bolt M5 ´ 0.8 2 1 0.1 0.7
Front fork and front fork protector M6 ´ 1.0 6 7 0.7 5.1
Front fork and brake hose guide M5 ´ 0.8 1 4 0.4 2.2
Front fork and brake hose holder M6 ´ 1.0 1 10 1.0 7.2
Throttle grip cap M5 ´ 0.8 2 4 0.4 2.2
Throttle cable cap M4 ´ 0.7 2 1 0.1 0.7
Front brake master cylinder M6 ´ 1.0 2 9 0.9 6.5
Brake lever mounting bolt M6 ´ 1.0 1 6 0.6 4.3
Brake lever mounting nut M6 ´ 1.0 1 6 0.6 4.3
Brake lever position locknut M6 ´ 1.0 1 5 0.5 3.6
Clutch lever holder M5 ´ 0.8 2 4 0.4 2.2
Front brake master cylinder cap M4 ´ 0.7 2 2 0.2 1.4
Front brake hose union bolt M10 ´ 1.25 2 26 2.6 19
Front fork and brake caliper bracket M8 ´ 1.25 2 30 3.0 22
Brake caliper support bolt M8 ´ 1.25 1 23 2.3 17
Front brake caliper and bleed screw M7 ´ 1.0 1 6 0.6 4.3
Rear brake caliper and brake caliper bracket M8 ´ 1.25 2 23 2.3 17
Rear brake caliper and pad pin M10 ´ 1.0 2 18 1.8 13
Rear brake caliper and bleed screw M8 ´ 1.25 1 6 0.6 4.3
Front wheel axle and axle nut M12 ´ 1.25 1 70 7.0 50
Front brake disc M6 ´ 1.0 3 12 1.2 8.7
Rear brake disc M6 ´ 1.0 4 12 1.2 8.7
Rear brake master cylinder M6 ´ 1.0 2 10 1.0 7.2
Rear brake reservoir tank M6 ´ 1.0 1 10 1.0 7.2
Rear brake hose union bolt M10 ´ 1.25 2 26 2.6 19
Rear wheel axle and axle nut M14 ´ 1.5 1 110 11.0 80

SPEC
2 - 13
MAINTENANCE SPECIFICATIONS
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Nipple (spoke) — 64 3 0.3 2.2
Rear wheel sprocket M8 ´ 1.25 4 42 4.2 30
Rear brake caliper protector M6 ´ 1.0 1 10 1.0 7.2
Engine mounting:
Engine and frame (front) M10 ´ 1.25 1 69 6.9 50
Engine and frame (lower) M10 ´ 1.25 1 69 6.9 50
Pivot shaft and nut M12 ´ 1.25 1 63 6.3 45
Relay arm and frame M10 ´ 1.25 1 54 5.4 39
Relay arm and connecting rod M12 ´ 1.25 1 53 5.3 38
Connecting rod and swingarm M12 ´ 1.25 1 53 5.3 38
Rear shock absorber and frame M10 ´ 1.25 1 36 3.6 25
Rear shock absorber and relay arm M10 ´ 1.25 1 36 3.6 25
Rear frame (upper) M8 ´ 1.25 1 26 2.6 19
Rear frame (lower) M8 ´ 1.25 2 16 1.6 11
Swingarm and brake hose holder M5 ´ — 4 4 0.4 2.9
Drive chain tensioner (upper) M8 ´ 1.25 1 23 2.3 17
Drive chain tensioner (lower) M6 ´ 1.0 1 10 1.0 7.2
Drive chain case M8 ´ 1.25 2 11 1.1 8
Seal guard and swingarm M6 ´ 1.0 2 10 1.0 7.2
Fuel tank M6 ´ 1.0 2 7 0.7 5.1
Fuel cock M6 ´ 1.0 2 4 0.4 2.9
Fuel tank bracket and fuel tank M6 ´ 1.0 4 7 0.7 5.1
Seat set bracket and fuel tank M6 ´ 1.0 1 7 0.7 5.1
Radiator cover M6 ´ 1.0 3 4 0.4 2.9
Front fender M6 ´ 1.0 4 7 0.7 5.1
Rear fender M6 ´ 1.0 4 7 0.7 5.1
Flap guard M6 ´ 1.0 2 7 0.7 5.1
Side cover M6 ´ 1.0 2 7 0.7 5.1
Seat M6 ´ 1.0 2 7 0.7 5.1
Number plate M6 ´ 1.0 1 7 0.7 5.1

2 - 16
SPEC
EC240000
CABLE ROUTING DIAGRAM
1Hose guide
2Brake hose
3Throttle cable
4Fuel tank breather hose
5Engine stop switch lead
6CDI magneto lead
7Clamp
8Carburetor breather hose
9Carburetor overflow hose
0Transmission oil breather hose
ARadiator breather hose
BClutch cable
CSpark plug leadDCable guide
EBrake hose holder
ÈPass the fuel tank breather hose between the
handlebar and tension bar, then insert its end
into the hole of the steering stem.
ÉFasten the ground lead together with the ignition
coil.
ÊClamp the brake hose with the brake hose
holder.
ËFit the brake hose into the guides of the protec-
tor.
CABLE ROUTING DIAGRAM

2 - 17
SPEC
1Sub-wire harness
2CDI unit
3Ignition coil
4Clutch cable
5Cable guide
6CDI unit band
7Clamp
8Brake hose
9Brake hose holder
0Hose guide
AReservoir hoseBReservoir tank
CBrake master cylinder
ÈClamp the sub-wire harness at the tape on it.
ÉPass the sub-wire harness on the left of the CDI
unit.
ÊPass the reservoir hose between the brake hose
and swingarm bracket.
ËPass the reservoir hose through the hose guides.
ÌInstall the brake hose so that its pipe portion
directs as shown and lightly touches the projec-
tion on the brake master cylinder.
5PA20070
CABLE ROUTING DIAGRAM

2 - 18
SPEC
1Throttle cable
2Clutch cable
3Clamp
4Engine stop switch lead
5Brake hose
6Hose guideÈFasten the engine stop switch lead to the han-
dlebar with the plastic band.
ÉPass the brake hose in front of the number plate.
ÊCross the clutch cable and throttle cable over
the number plate boss.
5PA20070
CABLE ROUTING DIAGRAM

3 - 2
INSP
ADJ
MAINTENANCE INTERVALS
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolant
Inspect hoses
ll
ll
l
Every two years
OUTSIDE NUTS AND BOLTS
Retighten
ll
AIR FILTER
Clean and lubricate
Replace
ll
lUse foam air-filter oil
FRAME
Clean and inspect
ll
FUEL TANK, COCK
Clean and inspect
ll
BRAKES
Adjust lever position and pedal height
Lubricate pivot point
Check brake disc surface
Check fluid level and leakage
Retighten brake disc bolts, caliper
bolts, master cylinder bolts and union
bolts
Replace pads
Replace brake fluid
l
l
l
l
ll
l
l
l
l
l
l
Every one year
FRONT FORKS
Inspect and adjust
Replace oil
Replace oil seal
l
ll
l
l
Suspension oil “01”
FRONT FORK OIL SEAL AND DUST
SEAL
Clean and lube
llLithium base grease
REAR SHOCK ABSORBER
Inspect and adjust
Lube
Retighten
l
ll
ll(After
rain ride)
l
Molybdenum disulfide
grease
CHAIN GUARD AND ROLLERS
Inspect
l
SWINGARM
Inspect and retighten
Lube
l
ll
l
Molybdenum disulfide
grease
RELAY ARM, CONNECTING ROD
Inspect and retighten
Lube
l
ll
l
Molybdenum disulfide
grease
STEERING HEAD
Inspect free play and retighten
Clean and lube
Replace bearing
ll
l
l
Lithium base grease ItemAfter
break-inEvery
raceEvery
third
raceEvery
fifth
raceAs re-
quiredRemarks


3

3 - 4
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator cap.
Check the cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh mixture of oil and gasoline is filled in the fuel
tank. Check the fuel line for leakage.P.1-12
Transmission oilCheck that the oil level is correct. Check the crankcase for leak-
age.P.3-12 ~ 13
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-9
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10
Brakes Check the play of front brake and effect of front and rear brake. P.3-16 ~ 21
Drive chainCheck drive chain slack and alignment. Check that the drive
chain is lubricated properly.P.3-22 ~ 24
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-31 ~ 32
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-32 ~ 33
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-24 ~ 30
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or
when the front forks travel up and down.—
Exhaust pipe and silencerCheck that the exhaust pipe is tightly mounted and has no
cracks.P.4-2
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-22
Lubrication Check for smooth operation. Lubricate if necessary. P.3-34
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-16
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 19

3 - 16
INSP
ADJ
CHASSIS/BRAKE SYSTEM AIR BLEEDING
EC360000
CHASSIS
EC361012
BRAKE SYSTEM AIR BLEEDING
WARNING
Bleed the brake system if:
lThe system has been disassembled.
lA brake hose has been loosened or
removed.
lThe brake fluid is very low.
lThe brake operation is faulty.
A dangerous loss of braking performance
may occur if the brake system is not prop-
erly bleed.
1. Remove:
lReservoir cap
lDiaphragm
2. Bleed:
lBrake fluid
ÈFront
ÉRear
Air bleeding steps:
a. Add proper brake fluid to the reservoir.
b. Install the diaphragm. Be careful not to
spill any fluid or allow the reservoir to
overflow.
c. Connect the clear plastic tube 2 tightly to
the caliper bleed screw 1.
d. Place the other end of the tube into a con-
tainer.
e. Slowly apply the brake lever or pedal sev-
eral times.
f. Pull the lever in or push down on the
pedal. Hold the lever or pedal in position.
g. Loosen the bleed screw and allow the
lever or pedal to travel towards its limit.
h. Tighten the bleed screw when the lever or
pedal limit has been reached; then
release the lever or pedal.
T R..
Bleed screw:
6 Nm (0.6 m • kg, 4.3 ft • lb)
i. Repeat steps (e) to (h) until of the air bub-
bles have been removed from the system.
È
5PA30290
É
5PA30300