engine YAMAHA YZ85 2021 Owners Manual

Table of contents
Location of important la bels ........... 1-1
Safety information ............................ 2-1
Description ....................................... 3-1
Left view ......................................... 3-1
Right view ....................................... 3-2
Controls and instruments ............... 3-3
Instrument an d control functions ... 4-1
Handlebar switch............................ 4-1
Clutch lever .................................... 4-1
Shift pedal ...................................... 4-2
Brake lever...................................... 4-2
Brake pedal .................................... 4-3
Fuel tank cap .................................. 4-3
Fuel ................................................. 4-4
Fuel tank breather hose.................. 4-6
Fuel cock ........................................ 4-7
Starter (choke) knob ....................... 4-7
Kickstarter ...................................... 4-8
Seat ................................................ 4-8
Adjusting the front fork ................... 4-9
Front fork bleeding ....................... 4-11
Adjusting the shock absorber assembly ................................... 4-12
Removable sidestand ................... 4-15
YPVS system ................................ 4-16
For your safety – pre-operation
checks ............................................... 5-1
Operation an d important ri din g
points ................................................ 6-1
Engine break-in .............................. 6-1
Starting and warming up a cold
engine ......................................... 6-3
Starting a warm engine .................. 6-3
Shifting ........................................... 6-4
Parking ........................................... 6-5
Perio dic maintenance an d
a d justment ........................................ 7-1
Periodic maintenance and lubrication chart .......................... 7-2
Checking the spark plug ................ 7-6 Transmission oil .............................. 7-7
Coolant ............................................ 7-8
Cleaning the air filter element ....... 7-10
Adjusting the carburetor ............... 7-12
Adjusting the engine idling
speed ......................................... 7-13
Adjusting the throttle grip free play ............................................ 7-13
Tires .............................................. 7-14
Spoke wheels ................................ 7-16
Adjusting the clutch lever free play ............................................ 7-17
Checking the brake lever free play ............................................ 7-18
Checking the shift pedal ............... 7-18
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 ................................. 7-23
Checking and lubricating the
cables ........................................ 7-23
Checking and lubricating the throttle grip and cable ............... 7-24
Checking and lubricating the brake and clutch levers ............. 7-24
Checking and lubricating the
brake pedal ................................ 7-25
Lubricating the rear suspension.... 7-25
Lubricating the swingarm pivots ... 7-26
Checking the front fork ................. 7-26
Checking the steering ................... 7-27
Checking the wheel bearings ........ 7-27
Supporting the motorcycle ........... 7-28
Front wheel ................................... 7-28
Rear wheel .................................... 7-29
Troubleshooting ............................ 7-31
Troubleshooting chart ................... 7-32
Motorcycle care an d stora ge .......... 8-1
Matte color caution ......................... 8-1
Care................................................. 8-1
Storage............................................ 8-4
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Safety information
2-2
2sic motorcycle maintenance.
Certain maintenance can only
be carried out by certified staff.
 Many accidents involve inexperi-
enced operators.
• Make sure that you are qualified and that you only lend your mo-
torcycle to other qualified oper-
ators.
• Know your skills and limits. Staying within your limits may
help you to avoid an accident.
• We recommend that you prac- tice riding your motorcycle until
you have become thoroughly
familiar with the motorcycle and
all of its controls.
 Many accidents have been
caused by error of the motorcycle
operator. A typical error made by
the operator is veering wide on a
turn due to excessive speed or un-
dercornering (insufficient lean an-
gle for the speed). Never travel
faster than warranted by condi-
tions.
 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 opera-
tion to maintain control of the mo-
torcycle.
 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 pre-
vention 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 abra-
sions 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.
Avoi d Car bon Monoxi de Poisonin g
All engine exhaust contains carbon
monoxide, a deadly gas. Breathing
carbon monoxide can cause head-
aches, dizziness, drowsiness, nausea,
confusion, and eventually death.
Carbon Monoxide is a colorless, odor-
less, tasteless gas which may be pres-
ent even if you do not see or smell any
engine exhaust. Deadly levels of car-
bon monoxide can collect rapidly and
you can quickly be overcome and un-
able to save yourself. Also, deadly lev-
els of carbon monoxide can linger for
hours or days in enclosed or poorly
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Safety information
2-3
2
ventilated areas. If you experience any
symptoms of carbon monoxide poi-
soning, 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.
 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 ac-
cessories 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, an
d
Mo difications
While you may find aftermarket prod-
ucts similar in design and quality to
genuine Yamaha accessories, recog-
nize that some aftermarket accesso-
ries or modifications are not suitable
because of potential safety hazards to
you or others. Installing aftermarket
products or having other modifications
performed 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 or
cornering clearance, limit suspen-
sion travel, steering travel or con-
trol operation.
• Accessories fitted to the han- dlebar or the front fork area can
create instability due to improp-
er weight distribution. If acces-
sories 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-
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Safety information
2-4
2tempt to lift the motorcycle, or
the motorcycle may become
unstable in cross winds.
• Certain accessories can dis- place the operator from his or
her normal riding position. This
improper position limits the
freedom of movement of the
operator and may limit control
ability, therefore, such accesso-
ries are not recommended.
 Use caution when adding electri-
cal accessories. If electrical ac-
cessories exceed the capacity of
the motorcycle’s electrical sys-
tem, an electric failure could re-
sult, which could cause a
dangerous loss of lights or engine
power.
Aftermarket Tires an d Rims
The tires and rims that came with your
motorcycle were designed to match
the performance capabilities and to
provide the best combination of han-
dling, braking, and comfort. Other
tires, rims, sizes, and combinations
may not be appropriate. Refer to page
7-14 for tire specifications and more in-
formation on replacing your tires.
Transportin g the Motorcycle
Be sure to observe following instruc-
tions before transporting the motorcy-
cle in another vehicle.  Remove all loose items from the
motorcycle.
 Check that the fuel cock (if
equipped) is in the “OFF” position
and that there are no fuel leaks. 
Point the front wheel straight
ahead on the trailer or in the truck
bed, and choke it in a rail to pre-
vent movement.
 Shift the transmission in gear (for
models with a manual transmis-
sion).
 Secure the motorcycle with tie-
downs or suitable straps that are
attached to solid parts of the mo-
torcycle, such as the frame or up-
per front fork triple clamp (and not,
for example, to rubber-mounted
handlebars or turn signals, or
parts that could break). Choose
the location for the straps carefully
so the straps will not rub against
painted surfaces during transport.
 The suspension should be com-
pressed somewhat by the tie-
downs, if possible, so that the mo-
torcycle will not bounce exces-
sively during transport.
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Description
3-3
3
EAU63401
Controls and instruments
1324
1. Clutch lever (page 4-1)
2. Engine stop switch (page 4-1)
3. Brake lever (page 4-2)
4. Throttle grip (page 7-13)
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Instrument and control functions
4-1
4
EAU40661
Han dle bar switch
EAU53962En gine stop switch “ENGINE STOP”
Hold this switch pushed until the en-
gine stops.
EAU64023
Clutch lever
The clutch lever is located on the left
side of the handlebar. To disengage
the clutch, pull the lever toward the
handlebar grip. To engage the clutch,
release the lever. The lever should be
pulled rapidly and released slowly for
smooth clutch operation.
The clutch lever is equipped with a
clutch lever position adjusting bolt. Ad-
just the distance between the clutch le-
ver and the handlebar grip as follows. 1. Loosen the locknut.
2. While holding the clutch lever pulled slightly towards the handle-
bar grip, turn the adjusting bolt in
direction (a) to increase the dis-
tance, and in direction (b) to de-
crease it.
3. Tighten the locknut.
1. Engine stop switch “ENGINE STOP”
1. Clutch lever
2. Locknut
3. Clutch lever position adjusting bolt
4. Distance between clutch lever and handle- bar grip
4 2
13
(b)
(a)
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Instrument and control functions
4-4
4
EAU41838
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
ECA15602
Always use fresh g asoline, and fill
the fuel tank with a fresh mix just be-
fore ri din g. Do not use premixe d fuel
that is more than a few hours ol d.
Mixin g g asoline an d 2-stroke en gine
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. Why Yamalu
be
YAMALUBE oil is a Genuine YAMAHA Part born of the engineers’ passion
and belief that engine oil is an impor-
tant liquid engine component. We form
teams of specialists in the fields of me-
chanical engineering, chemistry, elec-
tronics and track testing, and have
them develop the engine together with
the oil it will use. Yamalube oils take full
advantage of the base oil’s qualities
and blend in the ideal balance of addi-
tives to make sure the final oil clears
our performance standards. Thus,
Yamalube mineral, semisynthetic and synthetic oils have their own distinct
characters and value. Yamaha’s expe-
rience gained over many years of re-
search and development into oil since
the 1960’s helps make Yamalube the
best choice for your Yamaha engine.
If the recommended 2-stroke engine
oil is not available, use an equivalent
high-quality oil.
NOTICE
ECA15552
Never mix two b rands of 2-stroke
en gine oil in the same b atch. Always
use the same type of oil to ensure
maximum eng ine performance.
Shoul d it b e necessary to use a d if-
ferent oil bran d, b e sure to drain the
fuel tank an d the car buretor float
cham ber of the ol d premixe d fuel
prior to fillin g with the new type.
1. 2-stroke engine oil
2. Gasoline
3. Container
Recommen ded fuel:
Premium unleaded gasoline (E10
acceptable)
Recommen ded 2-stroke en gine oil:
YA M A L U B E 2 R
Fuel tank capacity: 5.0 L (1.3 US gal, 1.1 Imp.gal)
Mixin g ratios ( gasoline to oil):
Break-in period: 15:1
After break-in: 30:1
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Instrument and control functions
4-5
4 Gasoline
This model’s engine is designed to use
premium unleaded gasoline with a
pump octane number [(R+M)/2] of 91
or higher, or a research octane number
(RON) of 95 or higher. If knocking or
pinging occurs, try a gasoline of a dif-
ferent brand.
NOTICE
ECA15591
Use only unlea
ded g asoline. The use
of lea ded 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.
Gasohol
There are two types of gasohol: gaso-
hol containing ethanol and that con-
taining methanol. Gasohol containing
ethanol can be used if the ethanol con-
tent does not exceed 10% (E10). Gas-
ohol containing methanol should not
be used as it can cause engine or fuel
system problems.
Fillin g the fuel tank
WARNING
EWA10882
Gasoline an d gasoline vapors are
extremely flammab le. To avoid fires
an d explosions an d to re duce 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 spille d fuel with a clean,
d ry, soft cloth, since fuel may
d eteriorate painte d surfaces or
plastic parts.
[ECA10072]
4. Be sure to securely close the fuel tank cap.
WARNING
EWA15152
Gasoline is poisonous an d can
cause injury or death. Han dle gaso-
line with care. Never siphon gasoline
b y mouth. If you shoul d swallow
some gasoline or inhale a lot of gas-
oline vapor, or get some gasoline in
your eyes, see your doctor imme di-
ately. If gasoline spills on your skin,
1. Maximum fuel level
2. Fuel tank filler tube
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Instrument and control functions
4-7
4
EAU41281
Fuel cock
The fuel cock supplies fuel from the
tank to the carburetor while filtering it
also.
The fuel cock has two positions:
OFF
With the lever in this position, fuel will
not flow. Always return the lever to this
position when the engine is not run-
ning.
ON
With the lever in this position, fuel flows
to the carburetor. Normal riding is done
with the lever in this position.
EAU13641
Starter (choke) knob
Starting a cold engine requires a richer
air-fuel mixture, which is supplied by
the starter (choke).
Move the knob in direction (a) to turn
on the starter (choke).
Move the knob in direction (b) to turn
off the starter (choke).
1. Arrow mark positioned over “OFF”
1. Arrow mark positioned over “ON”
1
1
1. Starter (choke) knob
1
(b)
(a)
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Instrument and control functions
4-8
4
EAU13651
Kickstarter
To start the engine, fold out the kick-
starter lever, move it down lightly with
your foot until the gears engage, and
then push it down smoothly but force-
fully. This model is equipped with a pri-
mary kickstarter, allowing the engine to
be started in any gear if the clutch is
disengaged. However, shifting the
transmission into the neutral position
before starting is recommended.
EAU46283
Seat
To remove the seat
Remove the bolts, and then slide the
seat to the rear and pull upward.
To install the seat
1. Fit the slot in the seat onto the pro- jection on the fuel tank, and insert
the projection on the seat into the
seat holder as shown.
2. Place the seat in the original posi- tion, and then tighten the bolts.
TIP
Make sure that the seat is properly se-
cured before riding.
1. Kickstarter lever
1
1. Bolt
1. Slot
2. Projection
3. Seat holder
1
1
2
3
2
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