2003 YAMAHA YZ85 tire pressure

SPEC
2 - 2
GENERAL SPECIFICATIONS
Fuel:
Type Premium unleaded gasoline only with a
research octane number of 95 or higher.
(Except for ZA)
Premium gasoline (For ZA)
Tank capacity 5.0 L (1.10 Imp gal, 1.32 US gal)
Carburetor:
Type/manufacturer PWK28/KEIHIN
Spark plug:
Type/manufacturer BR10EG/NGK (resistance type)
Gap 0.5 ~ 0.6 mm (0.020 ~ 0.024 in)
Clutch type: Wet, multiple-disc
Transmission: YZ85 YZ85LW
Primary reduction system Gear←
Primary reduction ratio 65/18 (3.611)←
Secondary reduction system Chain drive←
Secondary reduction ratio 47/14 (3.357) 52/14 (3.714)
(USA, S, NZ, ZA)
48/14 (3.429)
(F, D, I, GB, E, CDN,
AUS)
Transmission type Constant mesh,
6-speed←
Operation Left foot operation←
Gear ratio: 1st 27/11 (2.454)←
2nd 32/17 (1.882)←
3rd 26/17 (1.529)←
4th 22/17 (1.294)←
5th 26/23 (1.130)←
6th 25/25 (1.000)←
Chassis: YZ85 YZ85LW
Frame type Semi double cradle←
Caster angle 26.3° 26.9°
Trail 88 mm (3.46 in) 105.5 mm (4.15 in)
Tire: YZ85 YZ85LW
Type With tube←
Size (front) 70/100-17 40M 70/100-19 42M
Size (rear) 90/100-14 49M 90/100-16 52M
Tire pressure (front and rear) 100 kPa
(1.0 kgf/cm
2, 15 psi)←
Brake:
Front brake type Single disc brake
Operation Right hand operation
Rear brake type Single disc brake
Operation Right foot operation

2

3 - 3
INSP
ADJ
MAINTENANCE INTERVALS
TIRE, WHEELS
Inspect air pressure, wheel run-out,
tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
Lubricate












Lithium base grease
THROTTLE, CONTROL CABLE
Check routing and connection
Inspect and Lubricate






Yamaha cable lube or
SAE 10W-30 motor oil ItemAfter
break-inEvery
raceEvery
third
raceEvery
fifth
raceAs re-
quiredRemarks

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 ~ 34
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.3-35
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 - 31
INSP
ADJTIRE PRESSURE CHECK/
SPOKES INSPECTION AND TIGHTENING
EC36Q000
TIRE PRESSURE CHECK
1. Measure:

Tire pressure
Out of specification → Adjust.
NOTE:

Check the tire while it is cold.

Loose bead stoppers allow the tire to slip off
its position on the rim when the tire pressure
is low.

A tilted tire valve stem indicates that the tire
slips off its position on the rim.

If the tire valve stem is found tilted, the tire is
considered to be slipping off its position. Cor-
rect the tire position.
Standard tire pressure:
100 kPa (1.0 kgf/cm2, 15 psi)
5PA30680
EC36S002
SPOKES INSPECTION AND TIGHTENING
1. Inspect:

Spokes 1
Bend/damage → Replace.
Loose spoke → Retighten.
2. Retighten:

Spokes
NOTE:
Be sure to retighten these spokes before and
after break-in. After a practice or a race check
spokes for looseness.
5PA30690
T R..3 Nm (0.3 m · kg, 2.2 ft · lb)

7 - 11
TUNSETTING
EC72N000
Drive and driven sprockets setting parts
YZ85:
*For USA, S, NZ and ZA
**For F, D, I, GB, E, CDN and AUS
YZ85LW:
Part name Size Part number
Drive (STD)
Sprocket
114T
15T9382A-14227
9382A-15228
Real wheel
sprocket
2*(STD)
** (STD)46T
47T
48T
49T5PA-25446-00
4ES-25447-10
5PA-25448-00
5PA-25449-00
Part name Size Part number
Drive (STD)
sprocket
1 14T
15T9382A-14227
9382A-15228
Real wheel
sprocket
2(STD)51T
52T
53T5PA-25451-00
5PA-25452-00
5PA-25453-00
5PA70120
EC721002
Tire pressure
Tire pressure should be adjust to suit the road
surface condition of the circuit.

Under a rainy, muddy, sandy, or slippery
condition, the tire pressure should be lower
for a larger area of contact with the road sur-
face.

Under a stony or hard road condition, the tire
pressure should be higher to prevent a flat
tire.
Standard tire pressure:
100 kPa (1.0 kgf/cm2, 15 psi)
Extent of adjustment:
60 ~ 80 kPa
(0.6 ~ 0.8 kgf/cm
2, 9.0 ~ 12 psi)
Extent of adjustment:
100 ~ 120 kPa
(1.0 ~ 1.2 kgf/cm
2, 15 ~ 18 psi)