2008 YAMAHA YZ85 radiator

DESCRIPTION
2-1
2
EAU10410
Left view1. Radiator cap (page 6-10)
2. Fuel cock (page 3-5)
3. Shock absorber assembly spring preload adjusting nut (page 3-9)
4. Air filter element (page 6-12)
5. Seat (page 3-6)
6. Shift pedal (page 3-1)
7. Throttle stop screw (page 6-14)
8. Starter (choke) knob (page 3-6)
U5PA86E0.book Page 1 Monday, April 9, 2007 3:16 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-4
6
NO. ITEM ROUTINEAfter
break-inEvery
raceEvery
third raceEvery
fifth raceAs
required
√
√
√ 13*CarburetorCheck carburetor settings and for obstructions.√
Adjust and clean.√
14 Spark plugCheck condition.
Clean and regap.√
Replace.√
15 Drive chainCheck chain slack, alignment and condition.
Adjust and thoroughly lubricate chain with Yamaha
chain and cable lube or equivalent.√
√
√
√ √
Replace.√
16* *
Cooling systemCheck coolant level and for leakage.√ √
Check hoses for cracks or damage.√
Check radiator cap spring operation.√
Change coolant. Every 2 years√
17*Chassis fastenersCheck all chassis fitting and fasteners.
Correct or tighten if necessary.√
18*Air filter elementClean.
√
Replace.√
19*FrameClean and check for damage.√
20*Fuel line Clean and check for leakage.√√
U5PA86E0.book Page 4 Monday, April 9, 2007 3:16 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-10
6
CAUTION:
ECA10452


In order to prevent clutch slip-
page (since the transmission oil
also lubricates the clutch), do
not mix any chemical additives.
Do not use oils with a diesel
specification of “CD” or oils of a
higher quality than specified. In
addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.


Make sure that no foreign mate-rial enters the transmission.
7. Start the engine, and then let it idle
for several minutes while checking
the transmission for oil leakage. If
oil is leaking, immediately turn the
engine off and check for the cause.
EAU20070
Coolant The coolant level should be checked
before each ride. In addition, the cool-
ant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAUM1292
To check the coolant level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.
WARNING
EWA10380
Never attempt to remove the radiatorcap when the engine is hot.
2. Remove the radiator cap and
check the coolant level in the radi-
ator.
NOTE:

The coolant level must be checked
on a cold engine since the level
varies with engine temperature.


Make sure that the vehicle is posi-
tioned straight up when checking
the coolant level. A slight tilt to theside can result in a false reading.
NOTE:The coolant should be at the bottom of
the radiator filler neck. The level will
change with variation of engine temper-ature.1. Radiator cap
U5PA86E0.book Page 10 Monday, April 9, 2007 3:16 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-11
6 3. If the coolant is below this level,
add coolant, and then install the
radiator cap.
NOTE:
If the engine overheats, see page 6-31for further instructions.
EAUM1312
To change the coolant
1. Place the vehicle on a level sur-
face and let the engine cool if nec-
essary.
2. Place a container under the engine
to collect the used coolant.
WARNING
EWA10380
Never attempt to remove the radiatorcap when the engine is hot.
3. Remove the coolant drain bolt and
then the radiator cap to drain the
cooling system.4. After the coolant is completely
drained, thoroughly flush the cool-
ing system with clean tap water.
5. Install the coolant drain bolt, and
then tighten it to the specified
torque.
NOTE:Check the washer for damage and re-place it if necessary.
6. Pour the recommended coolant
into the radiator until it is full.
1. Correct coolant level
1. Coolant drain bolt
1. Radiator cap
Tightening torque:
Coolant drain bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Antifreeze/water mixture ratio:
1:1
Recommended antifreeze:
High-quality ethylene glycol anti-
freeze containing corrosion inhibitors
for aluminum engines
Coolant quantity:
Radiator capacity (including all
routes):
0.54 L (0.57 US qt) (0.48 Imp.qt)
U5PA86E0.book Page 11 Monday, April 9, 2007 3:16 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-12
6
CAUTION:
ECA10471


If coolant is not available, use
distilled water or soft tap water
instead. Do not use hard water
or salt water since it is harmful
to the engine.


If water has been used instead
of coolant, replace it with cool-
ant as soon as possible, other-
wise the cooling system will not
be protected against frost and
corrosion.


If water has been added to the
coolant, have a Yamaha dealer
check the antifreeze content of
the coolant as soon as possible,
otherwise the effectiveness ofthe coolant will be reduced.
7. Install the radiator cap, start the
engine, let it idle for several min-
utes, and then turn it off.
8. Remove the radiator cap to check
the coolant level in the radiator. If
necessary, add sufficient coolant
until it reaches the bottom of the
radiator filler neck, and then install
the radiator cap.9. Start the engine, and then check
the vehicle for coolant leakage. If
coolant is leaking, have a Yamaha
dealer check the cooling system.
EAU41431
Cleaning the air filter element The air filter element should be cleaned
at the intervals specified in the periodic
maintenance and lubrication chart.
Clean the air filter element more fre-
quently if you are riding in unusually
wet or dusty areas.
1. Remove the seat. (See page 3-6.)
2. Remove the air filter case cover as
shown.1. Air filter case cover
U5PA86E0.book Page 12 Monday, April 9, 2007 3:16 PM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-32
6Engine overheating
WARNING
EWAT1040


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. Be sure to wait until the engine has cooled.


Place a thick rag, like a towel, over the radiator cap, and then slowly rotate the cap counterclockwise to the de-
tent to allow any residual pressure to escape. When the hissing sound has stopped, press down on the capwhile turning it counterclockwise, and then remove the cap.
NOTE:If coolant is not available, tap water can be temporarily used instead, provided that it is changed to the recommended coolantas soon as possible.
Wait until the
engine has cooled.
Check the coolant level in the
radiator.
The coolant level
is OK.The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer checkand repair the cooling system.Add coolant. (See NOTE.)
Start the engine. If the engine overheats again,
have a
Yamaha dealer check
and repair the cooling system.
There is
leakage.
There is
no leakage.
U5PA86E0.book Page 32 Monday, April 9, 2007 3:16 PM

SPECIFICATIONS
8-1
8
Dimensions:Overall length:
YZ85 1818 mm (71.6 in)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)
(FRA)(GBR)(GRC)(IRL)(NLD)(NOR)(PRT)
(SWE)
YZ85 1821 mm (71.7 in) (ZAF)
YZ85LW 1903 mm (74.9 in)
YZ85LWX 1903 mm (74.9 in)
YZ85X 1818 mm (71.6 in)
Overall width:
758 mm (29.8 in)
Overall height:
YZ85 1161 mm (45.7 in)
YZ85LW 1205 mm (47.4 in)
YZ85LWX 1205 mm (47.4 in)
YZ85X 1161 mm (45.7 in)
Seat height:
YZ85 864 mm (34.0 in)
YZ85LW 904 mm (35.6 in)
YZ85LWX 904 mm (35.6 in)
YZ85X 864 mm (34.0 in)
Wheelbase:
YZ85 1255 mm (49.4 in)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)
(FRA)(GBR)(GRC)(IRL)(NLD)(NOR)(PRT)
(SWE)
YZ85 1258 mm (49.5 in) (ZAF)
YZ85LW 1286 mm (50.6 in)
YZ85LWX 1286 mm (50.6 in)
YZ85X 1255 mm (49.4 in)Ground clearance:
YZ85 351 mm (13.82 in)
YZ85LW 393 mm (15.47 in)
YZ85LWX 393 mm (15.47 in)
YZ85X 351 mm (13.82 in)
Weight:With oil and fuel:
YZ85 71.0 kg (157 lb)
YZ85LW 73.9 kg (163 lb)
YZ85LWX 73.9 kg (163 lb)
YZ85X 71.0 kg (157 lb)Engine:Engine type:
Liquid cooled 2-stroke
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
84.7 cm³
Bore × stroke:
47.5 × 47.8 mm (1.87 × 1.88 in)
Compression ratio:
8.20 :1
Starting system:
Kickstarter
Lubrication system:
PremixEngine oil:Type:
YAMALUBE 2-RTransmission oil:Type:
YAMALUBE 4 (10W30) or SAE 10W30
type SE motor oilOil change quantity:
0.50 L (0.53 US qt) (0.44 Imp.qt)
Cooling system:Radiator capacity (including all routes):
0.54 L (0.57 US qt) (0.48 Imp.qt)Air filter:Air filter element:
Wet elementFuel:Recommended fuel:
Premium unleaded gasoline only
Fuel tank capacity:
5.0 L (1.32 US gal) (1.10 Imp.gal)Carburetor:Manufacturer:
KEIHIN
Type × quantity:
PWK28 x 1Spark plug (s):Manufacturer/model:
NGK/BR10EG
Spark plug gap:
0.5–0.6 mm (0.020–0.024 in)Clutch:Clutch type:
Wet, multiple-discTransmission:Primary reduction system:
Spur gear
Primary reduction ratio:
65/18 (3.611)
Secondary reduction system:
Chain drive
U5PA86E0.book Page 1 Monday, April 9, 2007 3:16 PM