2010 YAMAHA YZ85 open gas tank

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
U5PA88E0.book Page 3 Tuesday, June 9, 2009 8:44 AM

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

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
U5PA88E0.book Page 3 Tuesday, June 9, 2009 8:44 AM