INSTRUMENT AND CONTROL FUNCTIONS
4-4
4 Your Yamaha engine has been de-
signed to use premium unleaded gaso-
line with a pump octane number
[(R+M)/2] of 91 or higher, or a research
octane number of 95 or higher. If
knocking (or pinging) occurs, use a
gasoline of a different brand.
If the recommended 2-stroke engine oil
is not available, use an equivalent oil.
NOTICE
ECA15551
Never mix two brands of 2-stroke en-
gine oil in the same batch. Always
use the same type of oil to ensure
maximum engine performance.
Should it be necessary to use a dif-
ferent oil brand, be sure to drain the
fuel tank and the carburetor float
chamber of the old premixed fuel
prior to filling with the new type.
Filling the fuel tank
Make sure there is sufficient gasoline in
the tank.
WARNING
EWA10881
Gasoline and gasoline vapors are
extremely flammable. To avoid fires
and explosions and to reduce the
risk of injury when refueling, follow
these instructions.1. Before refueling, turn off the en-
gine and be sure that no one is sit-
ting on the vehicle. Never refuel
while smoking, or while in the vi-
cinity of sparks, open flames, orother sources of ignition such as
the pilot lights of water heaters and
clothes dryers.
2. Do not overfill the fuel tank. Stop
filling when the fuel reaches the
bottom of the filler tube. Because
fuel expands when it heats up,
heat from the engine or the sun
can cause fuel to spill out of the
fuel tank.
3. Wipe up any spilled fuel immedi-
ately. NOTICE: Immediately wipe
off spilled fuel with a clean, dry,
soft cloth, since fuel may deteri-
orate painted surfaces or plastic
parts.
[ECA10071]
4. Be sure to securely close the fuel
tank cap.
WARNING
EWA15151
Gasoline is poisonous and can
cause injury or death. Handle gaso-
line with care. Never siphon gaso-
line by mouth. If you should swallow
some gasoline or inhale a lot of gas-
oline vapor, or get some gasoline in
your eyes, see your doctor immedi-
ately. If gasoline spills on your skin,
1. Maximum fuel level
2. Fuel tank filler tube
U5PA88E0.book Page 4 Tuesday, June 9, 2009 8:44 AM
PERIODIC MAINTENANCE AND ADJUSTMENT
7-13
7 5. Clean the sponge material with
solvent, and then squeeze the re-
maining solvent out.
6. Apply oil of the recommended type
to the entire surface of the sponge
material, and then squeeze the ex-
cess oil out.
TIPThe sponge material should be wet but
not dripping.7. Pull the sponge material over the
air filter element frame.
8. Insert the air filter element into the
air filter case with the projection
facing upward, and then install the
washer and wing bolt. NOTICE:
Make sure that the air filter ele-
ment is properly seated in the
air filter case. The engine
should never be operated with-
out the air filter element in-
stalled, otherwise the piston(s)
and/or cylinder(s) may become
excessively worn.
[ECA10481]
9. Install the air filter case cover in the
original position as shown.
10. Install the seat.
1. Sponge material
2. Air filter element frame
Recommended oil:
Yamaha foam air filter oil or other
quality foam air filter oil
1. Air filter element
2. Projection
U5PA88E0.book Page 13 Tuesday, June 9, 2009 8:44 AM
PERIODIC MAINTENANCE AND ADJUSTMENT
7-20
7
EAU22580
Checking the brake fluid level Front brake
Rear brake
Insufficient brake fluid may allow air to
enter the brake system, possibly caus-
ing it to become ineffective.Before riding, check that the brake fluid
is above the minimum level mark and
replenish if necessary. A low brake fluid
level may indicate worn brake pads
and/or brake system leakage. If the
brake fluid level is low, be sure to check
the brake pads for wear and the brake
system for leakage.
Observe these precautions:
When checking the fluid level,
make sure that the top of the brake
fluid reservoir is level.
Use only the recommended quality
brake fluid, otherwise the rubber
seals may deteriorate, causing
leakage and poor braking perfor-
mance.
Refill with the same type of brake
fluid. Mixing fluids may result in a
harmful chemical reaction and
lead to poor braking performance.
Be careful that water does not en-
ter the brake fluid reservoir when
refilling. Water will significantly
lower the boiling point of the fluid
and may result in vapor lock.
Brake fluid may deteriorate paint-
ed surfaces or plastic parts. Al-
ways clean up spilled fluid
immediately.
As the brake pads wear, it is nor-
mal for the brake fluid level to grad-
ually go down. However, if the
brake fluid level goes down sud-
denly, have a Yamaha dealer
check the cause.
1. Minimum level mark
1. Minimum level mark
Recommended brake fluid:
DOT 4
U5PA88E0.book Page 20 Tuesday, June 9, 2009 8:44 AM
PERIODIC MAINTENANCE AND ADJUSTMENT
7-22
7to chain slippage or breakage.
To prevent this from occurring,
keep the drive chain slack with-
in the specified limits.
[ECA10571]
TIPUsing the alignment marks on each
drive chain puller, make sure that both
drive chain pullers are in the same po-
sition for proper wheel alignment.3. Tighten both locknuts and the axle
nut to the specified torques.
EAU23015
Cleaning and lubricating the
drive chain The drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrica-
tion chart, otherwise it will quickly wear
out, especially when riding in dusty or
wet areas. Service the drive chain as
follows.NOTICE
ECA10582
The drive chain must be lubricated
after washing the motorcycle and
riding in the rain or wet areas.1. Remove all dirt and mud from the
drive chain with a brush or cloth.TIPFor a thorough cleaning, have a
Yamaha dealer remove the drive chain
and soak it in solvent.2. Spray Yamaha Chain and Cable
Lube or a high-quality spray-type
drive chain lubricant on the entire
chain, making sure that all side
plates and rollers have been suffi-
ciently oiled.
1. Axle nut
2. Drive chain puller
3. Locknut
4. Drive chain slack adjusting bolt
5. Alignment marks
54 3 2
Tightening torques:
Locknut:
16 Nm (1.6 m·kgf, 11 ft·lbf)
Axle nut:
90 Nm (9.0 m·kgf, 65 ft·lbf)
U5PA88E0.book Page 22 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
SPECIFICATIONS
9-3
9
Operation:
Right foot operation
Recommended fluid:
DOT 4Front suspension:Type:
Telescopic fork
Spring/shock absorber type:
Coil spring/oil damper
Wheel travel:
275.0 mm (10.83 in)Rear suspension:Type:
Swingarm (link suspension)
Spring/shock absorber type:
Coil spring/gas-oil damper
Wheel travel:
YZ85 282.0 mm (11.10 in)
YZ85LW 287.0 mm (11.30 in)
YZ85LWZ 287.0 mm (11.30 in)
YZ85Z 282.0 mm (11.10 in)Electrical system:Ignition system:
CDI
U5PA88E0.book Page 3 Tuesday, June 9, 2009 8:44 AM