2010 YAMAHA YZ85 engine

TABLE OF CONTENTS
LOCATION OF IMPORTANT
LABELS ............................................1-1
SAFETY INFORMATION .................. 2-1
DESCRIPTION .................................. 3-1
Left view .......................................... 3-1
Right view ........................................ 3-2
Controls and instruments ................3-3
INSTRUMENT AND CONTROL
FUNCTIONS....................................... 4-1
Handlebar switch ............................ 4-1
Clutch lever .................................... 4-1
Shift pedal ......................................4-1
Brake lever ..................................... 4-2
Brake pedal .................................... 4-2
Fuel tank cap .................................. 4-3
Fuel ................................................ 4-3
Fuel tank breather hose ................. 4-5
Fuel cock ........................................ 4-5
Starter (choke) knob ....................... 4-6
Kickstarter ......................................4-6
Seat ................................................ 4-7
Adjusting the front fork ................... 4-7
Front fork bleeding ......................... 4-9
Adjusting the shock absorber
assembly ..................................... 4-9
Removable sidestand ................... 4-12FOR YOUR SAFETY –
PRE-OPERATION CHECKS............. 5-1
OPERATION AND IMPORTANT
RIDING POINTS................................ 6-1
Starting and warming up a cold
engine ......................................... 6-1
Starting a warm engine .................. 6-1
Shifting ........................................... 6-2
Engine break-in .............................. 6-3
Parking ........................................... 6-4
PERIODIC MAINTENANCE AND
ADJUSTMENT................................... 7-1
Periodic maintenance and
lubrication chart .......................... 7-2
Checking the spark plug ................ 7-8
Transmission oil ............................. 7-9
Coolant ........................................ 7-10
Cleaning the air filter element ...... 7-12
Adjusting the carburetor ............... 7-14
Adjusting the engine idling
speed ........................................ 7-14
Adjusting the throttle cable free
play ........................................... 7-14
Tires ............................................. 7-15
Spoke wheels .............................. 7-17
Adjusting the clutch lever free
play ........................................... 7-17
Checking the front brake lever
free play .................................... 7-18Checking the shift pedal ............... 7-19
Checking the front and rear brake
pads .......................................... 7-19
Checking the brake fluid level ...... 7-20
Changing the brake fluid .............. 7-21
Drive chain slack .......................... 7-21
Cleaning and lubricating the drive
chain ......................................... 7-22
Checking and lubricating
the cables ................................. 7-23
Checking and lubricating
the throttle grip and cable ......... 7-23
Checking and lubricating
the brake and clutch levers ....... 7-23
Checking and lubricating
the brake pedal ......................... 7-24
Lubricating the swingarm pivots ... 7-24
Lubricating the rear suspension ... 7-25
Checking the front fork ................. 7-25
Checking the steering .................. 7-26
Checking the wheel bearings ....... 7-26
Supporting the motorcycle ........... 7-26
Front wheel .................................. 7-27
Rear wheel ................................... 7-28
Troubleshooting ........................... 7-29
Troubleshooting charts ................. 7-31
MOTORCYCLE CARE AND
STORAGE.......................................... 8-1
Matte color caution ......................... 8-1
Care ............................................... 8-1
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SAFETY INFORMATION
2-2
2


Many accidents have been caused
by error of the motorcycle opera-
tor. A typical error made by the op-
erator is veering wide on a turn
due to excessive speed or under-
cornering (insufficient lean angle
for the speed). Never travel faster
than warranted by conditions.


Ride cautiously in unfamiliar ar-
eas. You may encounter hidden
obstacles that could cause an ac-
cident.


The posture of the operator is im-
portant for proper control. The op-
erator should keep both hands on
the handlebar and both feet on the
operator footrests during operation
to maintain control of the motorcy-
cle.


Never ride under the influence of
alcohol or other drugs.


Be sure the transmission is in neu-
tral before starting the engine.Protective apparel
The majority of fatalities from motorcy-
cle accidents are the result of head in-
juries. The use of a safety helmet is the
single most critical factor in the preven-
tion or reduction of head injuries.


Always wear an approved helmet.


Wear a face shield or goggles.
Wind in your unprotected eyes
could contribute to an impairment
of vision that could delay seeing a
hazard.


The use of a jacket, heavy boots,
trousers, gloves, etc., is effective in
preventing or reducing abrasions
or lacerations.


Never wear loose-fitting clothes,
otherwise they could catch on the
control levers, footrests, or wheels
and cause injury or an accident.


Always wear protective clothing
that covers your legs, ankles, and
feet. The engine or exhaust sys-
tem become very hot during or af-
ter operation and can cause burns.Avoid Carbon Monoxide Poisoning
All engine exhaust contains carbon
monoxide, a deadly gas. Breathing car-
bon monoxide can cause headaches,
dizziness, drowsiness, nausea, confu-
sion, and eventually death.
Carbon Monoxide is a colorless, odor-
less, tasteless gas which may be
present even if you do not see or smell
any engine exhaust. Deadly levels of
carbon monoxide can collect rapidly
and you can quickly be overcome and
unable to save yourself. Also, deadly
levels of carbon monoxide can linger
for hours or days in enclosed or poorly
ventilated areas. If you experience any
symptoms of carbon monoxide poison-
ing, leave the area immediately, get
fresh air, and SEEK MEDICAL TREAT-
MENT.


Do not run engine indoors. Even if
you try to ventilate engine exhaust
with fans or open windows and
doors, carbon monoxide can rap-
idly reach dangerous levels.


Do not run engine in poorly venti-
lated or partially enclosed areas
such as barns, garages, or car-
ports.
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SAFETY INFORMATION
2-3
2


Do not run engine outdoors where
engine exhaust can be drawn into
a building through openings such
as windows and doors.
Genuine Yamaha Accessories
Choosing accessories for your vehicle
is an important decision. Genuine
Yamaha accessories, which are avail-
able only from a Yamaha dealer, have
been designed, tested, and approved
by Yamaha for use on your vehicle.
Many companies with no connection to
Yamaha manufacture parts and acces-
sories or offer other modifications for
Yamaha vehicles. Yamaha is not in a
position to test the products that these
aftermarket companies produce.
Therefore, Yamaha can neither en-
dorse nor recommend the use of ac-
cessories not sold by Yamaha or
modifications not specifically recom-
mended by Yamaha, even if sold and
installed by a Yamaha dealer.Aftermarket Parts, Accessories, and
Modifications
While you may find aftermarket prod-
ucts similar in design and quality to
genuine Yamaha accessories, recog-
nize that some aftermarket accessories
or modifications are not suitable be-
cause of potential safety hazards to you
or others. Installing aftermarket prod-
ucts or having other modifications per-
formed to your vehicle that change any
of the vehicle’s design or operation
characteristics can put you and others
at greater risk of serious injury or death.
You are responsible for injuries related
to changes in the vehicle.
Keep the following guidelines in mind,
as well as those provided under “Load-
ing” when mounting accessories.


Never install accessories that
would impair the performance of
your motorcycle. Carefully inspect
the accessory before using it to
make sure that it does not in any
way reduce ground clearance orcornering clearance, limit suspen-
sion travel, steering travel or con-
trol operation.
Accessories fitted to the handle-
bar or the front fork area can
create instability due to improper
weight distribution. If accesso-
ries are added to the handlebar
or front fork area, they must be
as lightweight as possible and
should be kept to a minimum.
Bulky or large accessories may
seriously affect the stability of
the motorcycle. Wind may at-
tempt to lift the motorcycle, or
the motorcycle may become un-
stable in cross winds.
Certain accessories can dis-
place the operator from his or
her normal riding position. This
improper position limits the free-
dom of movement of the opera-
tor and may limit control ability,
therefore, such accessories are
not recommended.


Use caution when adding electri-
cal accessories. If electrical acces-
sories exceed the capacity of the
motorcycle’s electrical system, an
U5PA88E0.book Page 3 Tuesday, June 9, 2009 8:44 AM

SAFETY INFORMATION
2-4
2electric failure could result, which
could cause a dangerous loss of
lights or engine power.
Aftermarket Tires and Rims
The tires and rims that came with your
motorcycle were designed to match the
performance capabilities and to provide
the best combination of handling, brak-
ing, and comfort. Other tires, rims, siz-
es, and combinations may not be
appropriate. Refer to page 7-15 for tire
specifications and more information on
replacing your tires.
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DESCRIPTION
3-3
3
EAU10430
Controls and instruments1. Clutch lever (page 4-1)
2. Engine stop button (page 4-1)
3. Brake lever (page 4-2)
4. Throttle grip (page 7-14)
5. Fuel tank cap (page 4-3)
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INSTRUMENT AND CONTROL FUNCTIONS
4-1
4
EAU40660
Handlebar switch
EAU12670
“ENGINE STOP” button
Hold this button pushed until the engine
stops in case of an emergency, such as
when the vehicle overturns or when the
throttle cable is stuck.
EAU12850
Clutch lever The clutch lever is located at the left
handlebar grip. To disengage the
clutch, pull the lever toward the handle-
bar grip. To engage the clutch, release
the lever. The lever should be pulled
rapidly and released slowly for smooth
clutch operation.
EAU12870
Shift pedal The shift pedal is located on the left
side of the engine and is used in com-
bination with the clutch lever when
shifting the gears of the 6-speed con-
stant-mesh transmission equipped on
this motorcycle.
1. Engine stop button “ENGINE STOP”
1. Clutch lever
1. Shift pedal
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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
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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