2010 YAMAHA YZ85 cooling

FOR YOUR SAFETY – PRE-OPERATION CHECKS
5-1
5
EAU15596
Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always follow the inspection
and maintenance procedures and schedules described in the Owner’s Manual.
WARNING
EWA11151
Failure to inspect or maintain the vehicle properly increases the possibility of an accident or equipment damage.
Do not operate the vehicle if you find any problem. If a problem cannot be corrected by the procedures provided in
this manual, have the vehicle inspected by a Yamaha dealer.Before using this vehicle, check the following points:
ITEM CHECKS PAGE
FuelCheck fuel level in fuel tank.
Always use a fresh mixture of gasoline and oil.
Check fuel line for leakage.4-3
Transmission oilCheck oil level in transmission case.
If necessary, add recommended oil to specified level.7-9
CoolantCheck coolant level.
If necessary, add recommended coolant to specified level.
Check cooling system for leakage.7-10
Front brakeCheck operation.
If soft or spongy, have Yamaha dealer bleed hydraulic system.
Check brake pads for wear.
Replace if necessary.
Check fluid level in reservoir.
If necessary, add recommended brake fluid to specified level.
Check hydraulic system for leakage.7-19, 7-20
U5PA88E0.book Page 1 Tuesday, June 9, 2009 8:44 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-4
7
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.√√
U5PA88E0.book Page 4 Tuesday, June 9, 2009 8:44 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-11
7 is not available, use distilled wa-
ter 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 anti-
freeze content of the coolant as
soon as possible, otherwise the
effectiveness of the coolant will
be reduced.
[ECA10472]
EAUM1314
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.
3. Remove the coolant drain bolt and
the gasket, and then the radiator
cap to drain the cooling system.WARNING! Never attempt to re-
move the radiator cap when the
engine is hot.
[EWA10381]
4. After the coolant is completely
drained, thoroughly flush the cool-
ing system with clean tap water.5. Install a new gasket and the cool-
ant drain bolt, and then tighten the
bolt to the specified torque.
6. Pour the recommended coolant
into the radiator until it is full.
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.1. Coolant drain bolt
2. Gasket
1. Radiator cap
1
1
2
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)
U5PA88E0.book Page 11 Tuesday, June 9, 2009 8:44 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-12
79. Start the engine, and then check
the vehicle for coolant leakage. If
coolant is leaking, have a Yamaha
dealer check the cooling system.
EAU41433
Cleaning the air filter element The air filter element should be cleaned
or replaced at the intervals specified in
the periodic maintenance and lubrica-
tion chart. Clean or, if necessary, re-
place the air filter element more
frequently if you are riding in unusually
wet or dusty areas.
1. Remove the seat. (See page 4-7.)
2. Remove the air filter case cover as
shown.3. Remove the air filter element by
removing the wing bolt and wash-
er.
4. Remove the sponge material from
the air filter element frame.1. Air filter case cover
1. Wing bolt
2. Washer
3. Air filter element
U5PA88E0.book Page 12 Tuesday, June 9, 2009 8:44 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-32
7Engine 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 cap
while turning it counterclockwise, and then remove the cap.
TIPIf coolant is not available, tap water can be temporarily used instead, provided that it is changed to the recommended coolant
as 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 TIP.)
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.
U5PA88E0.book Page 32 Tuesday, June 9, 2009 8:44 AM

SPECIFICATIONS
9-1
9
Dimensions:Overall length:
YZ85 1818 mm (71.6 in)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)
(FRA)(GBR)(GRC)(IRL)(ITA)(NLD)(NOR)
(POL)(PRT)(SVN)(SWE)
YZ85 1821 mm (71.7 in) (ZAF)
YZ85LW 1903 mm (74.9 in)
YZ85LWZ 1903 mm (74.9 in)
YZ85Z 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)
YZ85LWZ 1205 mm (47.4 in)
YZ85Z 1161 mm (45.7 in)
Seat height:
YZ85 864 mm (34.0 in)
YZ85LW 904 mm (35.6 in)
YZ85LWZ 904 mm (35.6 in)
YZ85Z 864 mm (34.0 in)
Wheelbase:
YZ85 1255 mm (49.4 in)
(AUT)(BEL)(CHE)(DEU)(DNK)(ESP)(FIN)
(FRA)(GBR)(GRC)(IRL)(ITA)(NLD)(NOR)
(POL)(PRT)(SVN)(SWE)
YZ85 1258 mm (49.5 in) (ZAF)
YZ85LW 1286 mm (50.6 in)
YZ85LWZ 1286 mm (50.6 in)
YZ85Z 1255 mm (49.4 in)Ground clearance:
YZ85 351 mm (13.82 in)
YZ85LW 393 mm (15.47 in)
YZ85LWZ 393 mm (15.47 in)
YZ85Z 351 mm (13.82 in)
Weight:With oil and fuel:
YZ85 71.0 kg (157 lb)
YZ85LW 73.9 kg (163 lb)
YZ85LWZ 73.9 kg (163 lb)
YZ85Z 71.0 kg (157 lb)Engine:Engine type:
Liquid cooled 2-stroke
Cylinder arrangement:
Forward-inclined single cylinder
Displacement:
84 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 (10W-40) or SAE 10W-40
Oil 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: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
U5PA88E0.book Page 1 Tuesday, June 9, 2009 8:44 AM