INSTRUMENT AND CONTROL FUNCTIONS
4-4
4Your 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, or other 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
U1SN81E0.book Page 4 Tuesday, June 12, 2012 3:17 PM
PERIODIC MAINTENANCE AND ADJUSTMENT
7-13
75. 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 theair filter element frame.
8. Apply all-purpose grease to the air filter element seat.
9. Insert the air filter element into the air filter case with the projection
facing upward, and then install the
wing bolt and its washer. 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]
NOTICE:
Be sure to install the
washer with its curved side fac-
ing outward as shown.
[ECA16691]
1. Sponge material
2. Air filter element frame
1 2
Recommended oil:
Yamaha foam air filter oil or other
quality foam air filter oil1. Air filter element seat
1
1. Air filter element
2. Projection
U1SN81E0.book Page 13 Tuesday, June 12, 2012 3:17 PM
PERIODIC MAINTENANCE AND ADJUSTMENT
7-21
7Rear brake
WARNING
EWA15990
Improper maintenance can result in
loss of braking ability. Observe
these precautions:●
Insufficient brake fluid may al-
low air to enter the brake sys-
tem, reducing braking
performance.
●
Clean the filler cap before re-
moving. Use only DOT 4 brake
fluid from a sealed container.
●
Use only the specified brake flu-
id; otherwise, the rubber seals
may deteriorate, causing leak-
age.
●
Refill with the same type of
brake fluid. Adding a brake fluid
other than DOT 4 may result in a
harmful chemical reaction.
●
Be careful that water does not
enter the brake fluid reservoir
when refilling. Water will signifi-
cantly lower the boiling point of
the fluid and may result in vapor
lock.
NOTICE
ECA17640
Brake fluid may damage painted sur-
faces or plastic parts. Always clean
up spilled fluid immediately.As the brake pads wear, it is normal for
the brake fluid level to gradually go
down. A low brake fluid level may indi-
cate worn brake pads and/or brake sys-
tem leakage; therefore, be sure to
check the brake pads for wear and the
brake system for leakage. If the brake fluid level goes down suddenly, have a
Yamaha dealer check the cause before further riding.
1. Minimum level markSpecified brake fluid: DOT 4
U1SN81E0.book Page 21 Tuesday, June 12, 2012 3:17 PM
PERIODIC MAINTENANCE AND ADJUSTMENT
7-23
7gine as well as other vital parts
of the motorcycle and can lead
to 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. 4. Make sure that the drive chain pull-
ers are in the same position, the
drive chain slack is correct, and
the drive chain moves smoothly.
EAU23016
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
ECA10583
The drive chain must be lubricated
after washing the motorcycle, riding
in the rain or riding in wet areas.1. Remove all dirt and mud from thedrive 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
5 4
32
Tightening torques:
Locknut:
16 Nm (1.6 m·kgf, 12 ft·lbf)
Axle nut:
90 Nm (9.0 m·kgf, 65 ft·lbf)
U1SN81E0.book Page 23 Tuesday, June 12, 2012 3:17 PM
SPECIFICATIONS
9-1
9
Dimensions:Overall length:YZ85 1818 mm (71.6 in)
YZ85D 1818 mm (71.6 in)
YZ85LW 1903 mm (74.9 in)
YZ85LWD 1903 mm (74.9 in)
Overall width:
758 mm (29.8 in)
Overall height: YZ85 1161 mm (45.7 in)
YZ85D 1161 mm (45.7 in)
YZ85LW 1205 mm (47.4 in)
YZ85LWD 1205 mm (47.4 in)
Seat height: YZ85 864 mm (34.0 in)
YZ85D 864 mm (34.0 in)
YZ85LW 904 mm (35.6 in)
YZ85LWD 904 mm (35.6 in)
Wheelbase:
YZ85 1255 mm (49.4 in)
YZ85D 1255 mm (49.4 in)
YZ85LW 1286 mm (50.6 in)
YZ85LWD 1286 mm (50.6 in)
Ground clearance: YZ85 351 mm (13.82 in)
YZ85D 351 mm (13.82 in)
YZ85LW 393 mm (15.47 in)
YZ85LWD 393 mm (15.47 in)Weight:Curb weight:
YZ85 71 kg (157 lb)
YZ85D 71 kg (157 lb)
YZ85LW 73 kg (161 lb)
YZ85LWD 73 kg (161 lb)
Engine:Engine type:Liquid cooled 2-stroke
Cylinder arrangement:
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 2RTransmission 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 ratio:
3.611 (65/18)
Final drive: Chain
Secondary reduction ratio: YZ85 3.428 (48/14)
YZ85D 3.428 (48/14)
YZ85LW 3.714 (52/14)
YZ85LWD 3.714 (52/14)
Transmission type:
Constant mesh 6-speed
Operation: Left foot operation
Gear ratio: 1st:2.454 (27/11)
2nd: 1.882 (32/17)
3rd:
1.529 (26/17)
4th: 1.294 (22/17)
U1SN81E0.book Page 1 Tuesday, June 12, 2012 3:17 PM
SPECIFICATIONS
9-2
9
5th:1.130 (26/23)
6th: 1.000 (25/25)
Chassis:Frame type:Semi double cradle
Caster angle: YZ85 26.30 °
YZ85D 26.30 °
YZ85LW 26.90 °
YZ85LWD 26.90 °
Trail:
YZ85 88 mm (3.5 in)
YZ85D 88 mm (3.5 in)
YZ85LW 105 mm (4.2 in)
YZ85LWD 105 mm (4.2 in)Front tire:Type:With tube
Size:
YZ85 70/100-17 40M
YZ85D 70/100-17 40M
YZ85LW 70/100-19 42M
YZ85LWD 70/100-19 42M
Manufacturer/model: DUNLOP/D756FRear tire:Type:
With tube Size:
YZ85 90/100-14 49M
YZ85D 90/100-14 49M
YZ85LW 90/100-16 52M
YZ85LWD 90/100-16 52M
Manufacturer/model: DUNLOP/D756
Tire air pressure (measured on cold
tires):
Front: 100 kPa (1.00 kgf/cm², 15 psi)
Rear:
100 kPa (1.00 kgf/cm², 15 psi)
Front wheel:Wheel type:Spoke wheel
Rim size:
YZ85 17x1.40
YZ85D 17x1.40
YZ85LW 19x1.40
YZ85LWD 19x1.40Rear wheel:Wheel type:Spoke wheel
Rim size:
YZ85 14x1.60
YZ85D 14x1.60
YZ85LW 16x1.85
YZ85LWD 16x1.85Front brake:Type:Single disc brake
Operation:
Right hand operation Specified brake fluid:
DOT 4
Rear brake:Type:
Single disc brake
Operation: Right foot operation
Specified brake 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)
YZ85D 282.0 mm (11.10 in)
YZ85LW 287.0 mm (11.30 in)
YZ85LWD 287.0 mm (11.30 in)Electrical system:Ignition system:
CDI
U1SN81E0.book Page 2 Tuesday, June 12, 2012 3:17 PM