2002 YAMAHA YZ85 engine coolant

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:
lThe machine you have purchased may differ
slightly from those shown in the following.
lDesigns and specifications are subject to
change without notice.
5PA10020
5PA10010
5PA10030
1

SPEC
2 - 1
GENERAL SPECIFICATIONS
EC200000
SPECIFICATIONS
EC211000
GENERAL SPECIFICATIONS
Model name: YZ85 YZ85LW
YZ85P1 (USA)
YZ85LC (EUROPE)
YZ85(P)
(CDN, AUS, NZ, ZA)YZ85LW (EUROPE)
YZ85LWP (AUS, NZ)
Model code number: YZ85 YZ85LW
5PA1
(USA, CDN, EUROPE,
NZ, ZA)
5PA2
(AUS)5SH1
(EUROPE, NZ)
5SH2
(AUS)
Dimensions: YZ85 YZ85LW
Overall length 1,821 mm (71.7 in) 1,896 mm (74.4 in)
(USA, S, NZ, ZA)
1,818 mm (71.6 in)
(F, D, I, GB, E, CDN,
AUS)
Overall width 758 mm (28.9 in)¬
Overall height 1,161 mm (45.7 in) 1,204 mm (47.4 in)
Seat height 864 mm (34.0 in) 902 mm (35.0 in)
Wheelbase 1,258 mm (49.5 in) 1,278 mm (50.3 in)
(USA, S, NZ, ZA)
1,255 mm (49.4 in)
(F, D, I, GB, E, CDN,
AUS)
Minimum ground clearance 351 mm (13.8 in) 391 mm (15.4 in)
Basic weight: YZ85 YZ85LW
With oil and full fuel tank 71 kg (156.5 lb) 73.9 kg (162.9 lb)
Engine:
Engine type Liquid cooled 2-stroke, gasoline
Cylinder arrangement Single cylinder, forward inclined
Displacement 84.7 cm
3 (2.98 lmp oz, 2.86 US oz)
Bore ´ stroke 47.5 ´ 47.8 mm (1.870 ´ 1.882 in)
Compression ratio 8.2 : 1
Starting system Kickstarter
Lubrication system: Premix (30 : 1) (Yamalube 2-R)
Oil type or grade (2-cycle):
Transmission oil Yamalube 4 (10W-30) or SAE 10W-30 type SE
motor oil
Periodic oil change 0.50 L (0.44 lmp qt, 0.52 US qt)
Total amount 0.55 L (0.48 lmp qt, 0.58 US qt)
Coolant capacity (including all routes): 0.54 L (0.48 Imp qt, 0.57 US qt)
Air filter: Wet type element
2

2

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 - 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:
lRadiator cap
3. Check:
lCoolant 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:
lCoolant drain bolt 1
3. Remove:
lRadiator cap
Drain the coolant completely.
4. Clean:
lCooling system
Thoroughly flush the cooling system with
clean tap water.
5. Install:
lCopper washer
lCoolant drain bolt
5PA30030
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
6. Fill:
lRadiator
lEngine
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:
lDo not mix more than one type of ethyl-
ene glycol antifreeze containing corro-
sion inhibitors for aluminum engine.
lDo not use water containing impurities or
oil.
7. Install:
lRadiator cap
Start the engine and warm it up for a sev-
eral minutes.
8. Check:
lCoolant level
Coolant level low ® Add coolant. Handling notes of coolant:
The coolant is harmful so it should be han-
dled with special care.
WARNING
lWhen coolant splashes to your eye.
Thoroughly wash your eye with water
and see your doctor.
lWhen coolant splashes to your clothes.
Quickly wash it away with water and
then with soap.
lWhen coolant is swallowed.
Quickly make him vomit and take him
to a doctor.
EC355000
RADIATOR CAP INSPECTION
1. Inspect:
lSeal (radiator cap) 1
lValve and valve seat 2
Crack/damage ® Replace.
Exist fur deposits 3 ® Clean or replace.
5PA30050

4 - 40
ENG
6. Install:
lRight crankcase cover 1
NOTE:
Mesh the impeller shaft gear 2 with primary
drive gear 3.
5PA41200
7. Install:
lBolt (right crankcase cover) 1
lCopper washer (oil drain bolt) 2
lOil drain bolt 3
lCopper washer (coolant drain bolt)
4
lCoolant drain bolt 5
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
5PA41210
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
8. Install:
lKickstarter crank 1
lWasher 2
lBolt (kickstarter crank) 3
NOTE:
Install the kickstarter crank closest to but not con-
tacting the pillar tube 4 and exhaust pipe 5.
5PA41220
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
9. Install:
lShift pedal 1
lBolt (shift pedal) 2
NOTE:
Install the shift pedal with the bottom of the
pedal outer diameter a as close to the center
of the engine mounting bolt 3 as possible.
5PA41230
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
KICK SHAFT, SHIFT SHAFT AND PRIMARY DRIVE GEAR

4 - 49
ENG
EC4M0000
ENGINE REMOVAL
5PA41490
Extent of removal Order Part name Q’ty Remarks
ENGINE REMOVAL
Preparation for removal Hold the machine by placing the
suitable stand under the frame.
WARNING
Support the machine securely so there is no
danger of it falling over.
Drain the coolant. Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Carburetor Refer to “CARBURETOR AND REED
VALVE” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Clutch cable Disconnect at engine side.
Radiator hose 1 Disconnect at cylinder head side.
Radiator hose 2 Disconnect at water pump side.
Spark plug cap
Disconnect the CDI magneto
lead.
ENGINE REMOVAL