2005 YAMAHA YZ85 radiator

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.1-13
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.1-17
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

3 - 8
INSP
ADJRADIATOR CAP OPENING PRESSURE INSPECTION/
COOLING SYSTEM INSPECTION
RADIATOR CAP OPENING PRESSURE
INSPECTION
1. Attach:

Radiator cap tester 1

Radiator cap tester adapter 2
NOTE:
Apply water on the radiator cap seal.
3Radiator cap
2. Apply the specified pressure.
3. Inspect:

Pressure
Impossible to maintain the specified pres-
sure for 10 seconds → Replace.
Radiator cap tester:
YU-24460-01/90890-01325
Radiator cap tester adapter:
YU-33984/90890-01352
Radiator cap opening pressure:
95 ~ 125 kPa (0.95 ~ 1.25 kg/cm2,
13.5 ~ 17.8 psi)
5PA30060
COOLING SYSTEM INSPECTION
1. Inspect:

Coolant level
2. Attach:

Radiator cap tester 1

Radiator cap tester adapter 2
3. Apply the specified pressure.
Radiator cap tester:
YU-24460-01/90890-01325
Radiator cap tester adapter:
YU-33984/90890-01352
Standard pressure:
180 kPa (1.8 kg/cm2, 25.6 psi)
5PA30070

3 - 9
INSP
ADJ
CLUTCH ADJUSTMENT
CAUTION:

Do not apply pressure more than speci-
fied pressure.

Radiator should be filled fully.
4. Inspect:

Pressure
Impossible to maintain the specified pres-
sure for 10 seconds → Repair.

Radiator 1

Radiator hose joint 2
Coolant leakage → Repair or replace.

Radiator hose 3
Swelling → Replace.
5PA30080
CLUTCH ADJUSTMENT
1. Check:

Clutch lever free play a
Out of specification → Adjust.
Clutch lever free play
a:
10 ~ 15 mm (0.39 ~ 0.59 in)
5PA30090
2. Adjust:

Clutch lever free play
NOTE:

Make minute adjustment on the lever side.

After adjustment, check proper operation of
clutch lever. Clutch lever free play adjustment steps:

Loosen the locknut 1.

Turn the adjuster 2 until free play a is
within the specified limits.

Tighten the locknut.
5PA30100

4 - 3
ENGRADIATOR
EC450001
RADIATOR
5PA40030
Extent of removal:
1 Radiator removal
Extent of removal Order Part name Q’ty Remarks
RADIATOR REMOVAL
Preparation for removal Drain the coolant. Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
Air scoop Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
1 Radiator guard 1
2 Radiator hose clamp 4 Only loosening.
3 Radiator hose 1 1
4 Radiator hose 2 1
5 Radiator breather hose 1
6Radiator 1
1

4 - 4
ENGRADIATOR
EC456000
HANDLING NOTE
WARNING
Do not remove the radiator cap when the
engine and radiator are hot. Scalding hot
fluid and steam may be blown out under
pressure, which could cause serious
injury.
When the engine has cooled, open the radi-
ator cap by the following procedure:
Place a thick rag, like a towel, over the radi-
ator cap, slowly rotate the cap counter-
clockwise to the detent. This procedure
allows any residual pressure to escape.
When the hissing sound has stopped,
press down on the cap while turning coun-
terclockwise and remove it.
EC454000
INSPECTION
Radiator
1. Inspect:

Radiator core 1
Obstruction → Blow out with compressed
air through rear of the radiator.
Bent fin → Repair or replace.
5PA40040
EC455000
ASSEMBLY AND INSTALLATION
Radiator
1. Install:

Radiator breather hose 1
To radiator 2.
5PA40050
2. Install:

Radiator 1

Bolt (radiator) 2
5PA40060