
INSTRUMENT AND CONTROL FUNCTIONS
4-3
4
EAU13182
Fuel tank cap To remove the fuel tank cap, turn it
counterclockwise, and then pull it off.
To install the fuel tank cap, insert it into
the tank opening, and then turn it clock-
wise.
WARNING
EWA11091
Make sure that the fuel tank cap is
properly closed after filling fuel.
Leaking fuel is a fire hazard.
EAU41833
Fuel This motorcycle has been designed to
use a premixed fuel of gasoline and 2-
stroke engine oil. Always mix the gaso-
line and oil in a clean container before
filling the fuel tank.NOTICE
ECA15601
Always use fresh gasoline, and fill
the fuel tank with a fresh mix just be-
fore riding. Do not use premixed fuel
that is more than a few hours old.Mixing gasoline and 2-stroke engine
oil
Pour 2-stroke engine oil into a clean
container, and then add gasoline. To
mix the fuel thoroughly, shake the con-
tainer from side to side.
NOTICE
ECA15590
Use only unleaded gasoline. The use
of leaded gasoline will cause severe
damage to internal engine parts,
such as the piston rings as well as to
the exhaust system.
1. Fuel tank cap
1. 2-stroke engine oil
2. Gasoline
3. ContainerRecommended fuel:
Premium unleaded gasoline only
Recommended 2-stroke engine oil:
See page 9-1.
Fuel tank capacity:
5.0 L (1.32 US gal, 1.10 Imp.gal)
Mixing ratios (gasoline to oil):
Break-in period: 15:1
After break-in: 30:1
U5PA89E0.book Page 3 Tuesday, June 15, 2010 10:34 AM
![YAMAHA YZ85 2011 Owners Manual 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 YAMAHA YZ85 2011 Owners Manual 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](/manual-img/51/54051/w960_54051-28.png)
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
U5PA89E0.book Page 4 Tuesday, June 15, 2010 10:34 AM

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.
Check fuel tank breather hose for obstructions, cracks or damage, and check
hose connection.4-3, 4-5
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
U5PA89E0.book Page 1 Tuesday, June 15, 2010 10:34 AM

OPERATION AND IMPORTANT RIDING POINTS
6-3
6
EAU41503
Engine break-in
WARNING
EWA10321
Failure to properly maintain the ve-
hicle or performing maintenance ac-
tivities incorrectly may increase
your risk of injury or death during
service or while using the vehicle. If
you are not familiar with vehicle ser-
vice, have a Yamaha dealer perform
service.1. Before starting the engine, fill the
fuel tank with a break-in oil-fuel
mixture as follows.
2. Start and warm up the engine.
Check the operation of the controls
and the engine stop button. (See
page 4-1.)
3. Operate the motorcycle in the low-
er gears at moderate throttle open-
ings for five to eight minutes. Stop
the engine and check the sparkplug condition (see page 7-8); it
will show a rich condition during
break-in.
4. Allow the engine to cool. Restart
the engine and operate the motor-
cycle as in the step above for five
minutes. Then, very briefly shift to
the higher gears and check the
full-throttle response. Stop the en-
gine and check the spark plug.
5. After again allowing the engine to
cool, restart and run the motorcy-
cle for five more minutes. Full
throttle and the higher gears may
be used, but sustained full-throttle
operation should be avoided. Stop
the engine and check the spark
plug again.
6. Allow the engine to cool, remove
the cylinder head and cylinder, and
inspect the piston and cylinder.
Remove any high spots on the pis-
ton with #600-grit wet sandpaper.
Clean all components and careful-
ly reassemble the cylinder head
and cylinder.
7. Drain the break-in oil-fuel mixture
from the fuel tank and refill with the
specified mix. (See page 4-3.)8. Start the engine and check the op-
eration of the motorcycle through-
out its entire operating range. Stop
the engine and check the spark
plug condition. Restart the motor-
cycle and ride it for about 10 to 15
more minutes. The motorcycle will
now be ready to ride normally.
After the engine break-in period, thor-
oughly check the motorcycle for loose
parts, oil leakage and any other prob-
lems. Be sure to inspect and make ad-
justments thoroughly, especially cable
and drive chain slack and loose
spokes. In addition, check all fittings
and fasteners for looseness, and tight-
en if necessary.
NOTICE
ECA15560
When any of the following parts
have been replaced, they must
be broken in.
Cylinder or crankshaft:
About one hour of break-in op-
eration is necessary.
Piston, rings or transmission
gears:
Recommended 2-stroke engine oil:
See page 9-1.
Mixing ratio (gasoline to oil):
15:1
U5PA89E0.book Page 3 Tuesday, June 15, 2010 10:34 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-9
7 To install the spark plug
1. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.
2. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
TIPIf a torque wrench is not available when
installing a spark plug, a good estimate
of the correct torque is 1/4–1/2 turn
past finger tight. However, the spark
plug should be tightened to the speci-
fied torque as soon as possible.3. Install the spark plug cap.
EAU41448
Transmission oil The transmission must be checked for
oil leakage before each ride. If any
leakage is found, have a Yamaha deal-
er check and repair the motorcycle. In
addition, the transmission oil must be
changed at the intervals specified in the
periodic maintenance and lubrication
chart.
1. Start the engine, warm it up for
several minutes, and then turn it
off.
2. Place the motorcycle on a level
surface and hold it in an upright po-
sition.
3. Place an oil pan under the trans-
mission case to collect the used
oil.
4. Remove the oil filler cap, the trans-
mission oil drain bolt and its gasket
to drain the oil from the transmis-
sion.5. Install the drain bolt and its new
gasket, and then tighten the bolt to
the specified torque.
6. Refill with the specified amount of
the recommended transmission
oil, and then install and tighten the
oil filler cap.
Tightening torque:
Spark plug:
20 Nm (2.0 m·kgf, 14 ft·lbf)
1. Transmission oil filler cap
2. Transmission oil drain bolt
3. Gasket
Tightening torque:
Transmission oil drain bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Recommended transmission oil:
See page 9-1.
Oil change quantity:
0.50 L (0.53 US qt, 0.44 Imp.qt)
21
2
3
U5PA89E0.book Page 9 Tuesday, June 15, 2010 10:34 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
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]
9. Install the air filter case cover in the
original position as shown.
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
1. Washer
1
U5PA89E0.book Page 13 Tuesday, June 15, 2010 10:34 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-23
7
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 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.
EAU23094
Checking and lubricating the
cables The operation of all control cables and
the condition of the cables should be
checked before each ride, and the ca-
bles and cable ends should be lubricat-
ed if necessary. If a cable is damaged
or does not move smoothly, have a
Yamaha dealer check or replace it.
WARNING! Damage to the outer
housing of cables may result in in-
ternal rusting and cause interfer-
ence with cable movement. Replace
damaged cables as soon as possi-
ble to prevent unsafe conditions.[EWA10711]EAU23114
Checking and lubricating the
throttle grip and cable The operation of the throttle grip should
be checked before each ride. In addi-
tion, the cable should be lubricated by a
Yamaha dealer at the intervals speci-
fied in the periodic maintenance chart.
The throttle cable is equipped with a
rubber cover. Make sure that the cover
is securely installed. Even though the
cover is installed correctly, it does not
completely protect the cable from water
entry. Therefore, use care not to pour
water directly onto the cover or cable
when washing the vehicle. If the cable
or cover becomes dirty, wipe clean with
a moist cloth.
Recommended lubricant:
Yamaha Chain and Cable Lube or 4-
stroke engine oil
U5PA89E0.book Page 23 Tuesday, June 15, 2010 10:34 AM

PERIODIC MAINTENANCE AND ADJUSTMENT
7-25
7
EAUM1651
Lubricating the swingarm piv-
ots The swingarm pivots must be lubricat-
ed by a Yamaha dealer at the intervals
specified in the periodic maintenance
and lubrication chart.
EAU23251
Lubricating the rear suspen-
sion The pivoting points of the rear suspen-
sion must be lubricated by a Yamaha
dealer at the intervals specified in the
periodic maintenance and lubrication
chart.
EAU23272
Checking the front fork The condition and operation of the front
fork must be checked as follows at the
intervals specified in the periodic main-
tenance and lubrication chart.
To check the condition
Check the inner tubes for scratches,
damage and excessive oil leakage.
To check the operation
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion. WARNING! To avoid injury,
securely support the vehicle so
there is no danger of it falling
over.
[EWA10751]
2. While applying the front brake,
push down hard on the handlebars
several times to check if the front
fork compresses and rebounds
smoothly.
Recommended lubricant:
Lithium-soap-based grease
Recommended lubricant:
Lithium-soap-based grease
U5PA89E0.book Page 25 Tuesday, June 15, 2010 10:34 AM