2003 YAMAHA YZ85 radiator cap

GEN
INFO
1 - 1
DESCRIPTION
EC100000
GENERAL INFORMATION
EC110000
DESCRIPTION
1Clutch lever
2Engine stop switch
3Front brake lever
4Throttle grip
5Fuel tank cap
6Radiator cap
7Kickstarter crank
8Fuel tank
9Coolant drain bolt
0Rear brake pedal
ARadiator
BValve joint
CFuel cock
DAir filter
EDrive chain
FShift pedal
GStarter knob
HFront forkNOTE:

The machine you have purchased may differ
slightly from those shown in the following.

Designs and specifications are subject to
change without notice.
5PA10020
5PA10010
5PAR0001

GEN
INFO
1 - 7
SPECIAL TOOLS
EC140002
SPECIAL TOOLS
The proper special tools are necessary for complete and accurate tune-up and assembly. Using the
correct special tool will help prevent damage caused by the use of improper tools or improvised
techniques. The shape and part number used for the special tool differ by country, so two types are
provided. Refer to the list provided to avoid errors when placing an order.
NOTE:

For U.S.A. and Canada, use part number starting with “YM-”, “YU-” or “ACC-”.

For others, use part number starting with “90890-”.
Part number Tool name/How to use Illustration
YU-1135-A, 90890-01135 Crankcase separating tool
This tool is used to split the crankcase as well as
remove the crankshaft from either case.YU-1135-A 90890-01135
YM-1189, 90890-01189 Flywheel puller
This tool is used to remove the flywheel magneto.YM-1189 90890-01189
YU-1235, 90890-01235 Rotor holding tool
This tool is used when loosening or tightening the fly-
wheel magneto securing nut.YU-1235 90890-01235
YU-3097, 90890-01252
YU-1256Dial gauge and stand
Stand
These tools are used to check each part for runout or
bent.YU-3097
YU-125690890-01252
YU-90050, 90890-01274
YU-90050, 90890-01275
YM-1277, 90890-01277Crankshaft installing tool
Crankshaft installing pot
Crankshaft installing bolt
Adapter (M10)
These tools are used to install the crankshaft.YU-90050
YM-127790890-01274
90890-01275
90890-01277
YU-1304, 90890-01304 Piston pin puller set
This tool is used to remove the piston pin.YU-1304 90890-01304
YU-24460-01, 90890-01325
YU-33984, 90890-01352Radiator cap tester
Radiator cap tester adapter
These tools are used for checking the cooling sys-
tem.YU-24460-01
YU-3398490890-01325
90890-01352
5PA102105PA10210
5PA102205PA10220
5PA10240
5PA102505PA10260
5PA102705PA10270
5PA102805PA10290

SPEC
2 - 6
MAINTENANCE SPECIFICATIONS
Reed valve:
Thickness “T”0.42 mm (0.017 in) ----
Valve stopper height 7.4 ~ 7.8 mm (0.291 ~ 0.307 in) ----
Valve bending limit ---- 0.2 mm
(0.008 in)
Cooling:
Radiator core size
Width 117.8 mm (4.64 in) ----
Height 240 mm (9.45 in) ----
Thickness 32 mm (1.26 in) ----
Radiator cap opening pressure 95 ~ 125 kPa (0.95 ~ 1.25 kg/cm
2,
13.5 ~ 17.8 psi)----
Radiator capacity 0.32 L (0.28 Imp qt, 0.34 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit

3 - 2
INSP
ADJ
MAINTENANCE INTERVALS
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolant
Inspect hoses








Every two years
OUTSIDE NUTS AND BOLTS
Retighten



AIR FILTER
Clean and lubricate
Replace




Use foam air-filter oil
FRAME
Clean and inspect



FUEL TANK, COCK
Clean and inspect



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























Every one year
FRONT FORKS
Inspect and adjust
Replace oil
Replace oil seal









Suspension oil “01”
FRONT FORK OIL SEAL AND DUST
SEAL
Clean and lube


Lithium base grease
REAR SHOCK ABSORBER
Inspect and adjust
Lube
Retighten







(After
rain ride)


Molybdenum disulfide
grease
DRIVE CHAIN GUIDE, ROLLERS AND
SUPPORT
Inspect


SWINGARM
Inspect and retighten
Lube







Molybdenum disulfide
grease
RELAY ARM, CONNECTING ROD
Inspect and retighten
Lube







Molybdenum disulfide
grease
STEERING HEAD
Inspect free play and retighten
Clean and lube
Replace bearing







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 ~ 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 - 5
INSP
ADJ
EC350000
ENGINE
COOLANT LEVEL INSPECTION
WARNING
Do not remove the radiator cap
1, drain
bolt and hoses when the engine and radia-
tor are hot. Scalding hot fluid and steam
may be blown out under pressure, which
could cause serious injury.
When the engine has cooled, place a thick
towel over the radiator cap, slowly rotate
the cap counterclockwise to the detent.
This procedure allows any residual pres-
sure to escape. When the hissing sound
has stopped, press down on the cap while
turning counterclockwise and remove it.
CAUTION:
Hard water or salt water is harmful to the
engine parts. You may use distilled water, if
you can’t get soft water.
5PA30010
1. Place the machine on a level place, and
hold it in an upright position.
2. Remove:

Radiator cap
3. Check:

Coolant level
Coolant level a low → Add coolant.
1Radiator
5PA30020
ENGINE/COOLANT LEVEL INSPECTION

3 - 6
INSP
ADJ
COOLANT REPLACEMENT
COOLANT REPLACEMENT
WARNING
Do not remove the radiator cap when the
engine is hot.
CAUTION:
Take care so that coolant does not splash
on painted surfaces. If it splashes, wash it
away with water.
1. Place a container under the engine.
2. Remove:

Coolant drain bolt 1
3. Remove:

Radiator cap
Drain the coolant completely.
4. Clean:

Cooling system
Thoroughly flush the cooling system with
clean tap water.
5. Install:

Copper washer

Coolant drain bolt
5PA30030
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
6. Fill:

Radiator

Engine
To specified level.
Recommended coolant:
High quality ethylene glycol
anti-freeze containing anti-
corrosion for aluminum engine
Coolant
1 and water (soft water)
2
mixing ratio:
50 %/50 %
Coolant capacity:
0.54 L (0.48 Imp qt, 0.57 US qt)
5PA30040

3 - 7
INSP
ADJ
RADIATOR CAP INSPECTION
CAUTION:

Do not mix more than one type of ethyl-
ene glycol antifreeze containing corro-
sion inhibitors for aluminum engine.

Do not use water containing impurities or
oil.
7. Install:

Radiator cap
Start the engine and warm it up for a sev-
eral minutes.
8. Check:

Coolant level
Coolant level low → Add coolant. Handling notes of coolant:
The coolant is harmful so it should be han-
dled with special care.
WARNING

When coolant splashes to your eye.
Thoroughly wash your eye with water
and see your doctor.

When coolant splashes to your clothes.
Quickly wash it away with water and
then with soap.

When coolant is swallowed.
Quickly make him vomit and take him
to a doctor.
EC355000
RADIATOR CAP INSPECTION
1. Inspect:

Seal (radiator cap) 1

Valve and valve seat 2
Crack/damage → Replace.
Exist fur deposits 3 → Clean or replace.
5PA30050