
INSTRUMENT AND CONTROL FUNCTIONS
4-4
4
NOTICE
ECA15591
Use only unleaded g asoline. The use
of lead ed g asoline will cause severe
d amag e to internal en gine parts,
such as the piston rin gs as well as to
the exhaust system.
Your Yamaha engine has been de-
signed to use premium unleaded gas-
oline 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
ECA15552
Never mix two bran ds of 2-stroke
en gine oil in the same batch. Always
use the same type of oil to ensure
maximum en gine performance.
Shoul d it b e necessary to use a dif-
ferent oil b rand, b e sure to d rain the
fuel tank an d the car buretor float
cham ber of the ol d premixe d fuel
prior to filling with the new type.
Filling the fuel tank
Make sure there is sufficient gasoline in
the tank.
WARNING
EWA10882
Gasoline an d g asoline vapors are
extremely flamma ble. To avoi d fires
an d explosions an d to re duce the
risk of injury when refuelin g, 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
1. 2-stroke engine oil
2. Gasoline
3. ContainerRecommen ded fuel:
Premium unleaded gasoline only
Recommen ded 2-stroke en gine oil:
See page 9-1.
Fuel tank capacity:
5.0 L (1.32 US gal, 1.10 Imp.gal)
Mixin g ratios ( gasoline to oil):
Break-in period: 15:1
After break-in: 30:1
1. Maximum fuel level
2. Fuel tank filler tube
U1SN83E0.book Page 4 Monday, September 8, 2014 2:36 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 excess 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 element is properly seate din the air filter case. The en
gine
shoul d never b e operated with-
out the air filter element in-
stalle d, otherwise the piston(s)
an d/or cylin der(s) may become
excessively worn.
[ECA10482]
NOTICE: Be sure to install the
washer with its curve d si de fac-
in g outwar d as shown.
[ECA16692]
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
U1SN83E0.book Page 13 Monday, September 8, 2014 2:36 PM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-21
7Rear
brake
WARNING
EWA15991
Improper maintenance can result in
loss of brakin g a bility. O bserve
these precautions: Insufficient brake flui d may al-
low air to enter the b rake sys-
tem, re ducin g brakin g
performance.
Clean the filler cap before re-
moving . Use only DOT 4 b rake
flui d from a seale d container.
Use only the specified b rake flu-
i d ; otherwise, the ru bber seals
may deteriorate, causin g leak-
a g e.
Refill with the same type of
brake flui d. A ddin g a brake flui d
other than DOT 4 may result in a
harmful chemical reaction.
Be careful that water does not
enter the brake flui d reservoir
when refillin g. Water will si gnifi-
cantly lower the boilin g point of
the flui d an d may result in vapor
lock.
NOTICE
ECA17641
Brake flui d may damag e painted
surfaces or plastic parts. Always
clean up spille d flui d imme diately.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
system 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 markSpecifie d b rake flui d:
DOT 4
U1SN83E0.book Page 21 Monday, September 8, 2014 2:36 PM

SPECIFICATIONS
9-1
9
Dimensions:Overall length:YZ85 1821 mm (71.7 in)
YZ85F 1821 mm (71.7 in)
YZ85LW 1899 mm (74.8 in)
YZ85LWF 1899 mm (74.8 in)
Overall width:
758 mm (29.8 in)
Overall height: YZ85 1126 mm (44.3 in)
YZ85F 1126 mm (44.3 in)
YZ85LW 1156 mm (45.5 in)
YZ85LWF 1156 mm (45.5 in)
Seat height: YZ85 841 mm (33.1 in)
YZ85F 841 mm (33.1 in)
YZ85LW 873 mm (34.4 in)
YZ85LWF 873 mm (34.4 in)
Wheelbase:
YZ85 1257 mm (49.5 in)
YZ85F 1257 mm (49.5 in)
YZ85LW 1285 mm (50.6 in)
YZ85LWF 1285 mm (50.6 in)
Ground clearance: YZ85 330 mm (12.99 in)
YZ85F 330 mm (12.99 in)
YZ85LW 360 mm (14.17 in)
YZ85LWF 360 mm (14.17 in)Wei ght:Curb weight:
YZ85 71 kg (157 lb)
YZ85F 71 kg (157 lb)
YZ85LW 73 kg (161 lb)
YZ85LWF 73 kg (161 lb)
Engine:Engine type:
Liquid cooled 2-stroke
Cylinder arrangement:
Single cylinder
Displacement: 85 cm³
Bore × stroke:
47.5 × 47.8 mm (1.87 × 1.88 in)
Compression ratio:
8.1 : 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)Coolant quantity:Radiator (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)
Car buretor:Type × quantity:
PWK28 x 1Spark plu g(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)
YZ85F 3.428 (48/14)
YZ85LW 3.714 (52/14)
YZ85LWF 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)
U1SN83E0.book Page 1 Monday, September 8, 2014 2:36 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 °
YZ85F 26.30 °
YZ85LW 26.00 °
YZ85LWF 26.00 °
Trail:
YZ85 88 mm (3.5 in)
YZ85F 88 mm (3.5 in)
YZ85LW 99 mm (3.9 in)
YZ85LWF 99 mm (3.9 in)Front tire:Type:With tube
Size:
YZ85 70/100-17 40M
YZ85F 70/100-17 40M
YZ85LW 70/100-19 42M
YZ85LWF 70/100-19 42M
Manufacturer/model: DUNLOP/MX51FRear tire:Type:
With tube Size:
YZ85 90/100-14 49M
YZ85F 90/100-14 49M
YZ85LW 90/100-16 52M
YZ85LWF 90/100-16 52M
Manufacturer/model: DUNLOP/MX51
Tire air pressure (measure d on col d
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
YZ85F 17x1.40
YZ85LW 19x1.40
YZ85LWF 19x1.40Rear wheel:Wheel type:Spoke wheel
Rim size:
YZ85 14x1.60
YZ85F 14x1.60
YZ85LW 16x1.85
YZ85LWF 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 mm (10.8 in)Rear suspension:Type:Swingarm (link suspension)
Spring/shock absorber type:
Coil spring/gas-oil damper
Wheel travel: YZ85 282 mm (11.1 in)
YZ85F 282 mm (11.1 in)
YZ85LW 287 mm (11.3 in)
YZ85LWF 287 mm (11.3 in)Electrical system:Ignition system:
CDI
U1SN83E0.book Page 2 Monday, September 8, 2014 2:36 PM