2021 YAMAHA YZ85 Owners Manual

Periodic maintenance an d a djustment
7-9
7
TIP
The coolant should be at the bottom of
the radiator filler neck. The level will
change with variation of engine tem-
perature.
3. If the coolant is below the correct
coolant level, add coolant, and
then install the radiator cap.
NOTICE: If coolant is not avail-
a b le, use distille d water or soft
tap water instead . Do not use
har d water or salt water since it
is harmful to the en gine. If water
has been used instead of cool-
ant, replace it with coolant as
soon as possi ble, otherwise the
coolin g system will not be pro-
tected against frost an d corro-
sion. If water has b een added to
the coolant, have a Yamaha
d ealer check the antifreeze con-
tent of the coolant as soon as
possi ble, otherwise the effec-
tiveness of the coolant will be
re duce d.
[ECA10473]
EAUM1318
To change the coolant
1. Place the vehicle on a level sur- face and let the engine cool if nec-
essary. 2. Place a container under the en-
gine to collect the used coolant.
3. Remove the radiator cap, and then the coolant drain bolt and its
gasket to drain the cooling sys-
tem. WARNING! Never attempt
to remove the ra diator cap
when the en gine is hot.
[EWA10382]
4. After the coolant is completely
drained, thoroughly flush the cool-
ing system with clean tap water.
5. Install the coolant drain bolt and its new gasket, and then tighten
the bolt to the specified torque.
1. Correct coolant level
1
1. Radiator cap
1. Coolant drain bolt
2. Gasket
Tightenin g torque:
Coolant drain bolt: 10 N·m (1.0 kgf·m, 7.4 lb·ft)
1
21
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Periodic maintenance an d a djustment
7-10
7 6. Pour the recommended coolant
into the radiator until it is full.
7. Install the radiator cap, start the engine, let it idle for several min-
utes, and then turn it off.
8. Remove the radiator cap to check the coolant level in the radiator. If
necessary, add sufficient coolant
until it reaches the bottom of the
radiator filler neck, and then install
the radiator cap.
9. Start the engine, and then check the vehicle for coolant leakage. If
coolant is leaking, have a Yamaha
dealer check the cooling system.
EAU48393
Cleanin g the air filter element
The air filter element should be cleaned
or replaced at the intervals specified in
the periodic maintenance and lubrica-
tion chart. Clean or, if necessary, re-
place the air filter element more
frequently if you are riding in unusually
wet or dusty areas.
1. Remove the seat. (See page 4-8.)
2. Remove the air filter case cover as shown.
3. Remove the air filter element by removing the wing bolt and its
washer.
Antifreeze/water mixture ratio:1:1
Recommen ded antifreeze:
High-quality ethylene glycol anti-
freeze containing corrosion inhibi-
tors for aluminum engines
Coolant quantity:
Radiator (including all routes):0.55 L (0.58 US qt, 0.48 Imp.qt)
1. Air filter case cover
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Periodic maintenance an d a djustment
7-11
7
4. Remove the sponge material from
the air filter element frame.
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 excess oil out.
TIP
The sponge material should be wet but
not dripping.
7. Pull the sponge material over theair 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 element is properly seated
in 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 curved side fac-
in g outwar d as shown.
[ECA16692]
1. Wing bolt
2. Washer
3. Air filter element
1. Sponge material
2. Air filter element frame
1
2
Recommended oil:
Yamaha foam air filter oil or other
quality foam air filter oil
1. Air filter element
2. Projection
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Periodic maintenance an d a djustment
7-12
7 9. Install the air filter case cover in
the original position as shown.
10. Install the seat.
EAU42111
A djustin g the car buretor
The carburetor is an important part of
the engine and requires very sophisti-
cated adjustment. Therefore, most
carburetor adjustments should be left
to a Yamaha dealer, who has the nec-
essary professional knowledge and ex-
perience. The adjustment described in
the following section, however, may be
serviced by the owner as part of rou-
tine maintenance.
NOTICE
ECA10551
The car buretor has been set an d ex-
tensively teste d at the Yamaha fac-
tory. Chan gin g these settin gs
without sufficient technical knowl-
e dge may result in poor perfor-
mance of or d amage to the en gine.
1. Washer
1
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Periodic maintenance an d a djustment
7-13
7
EAU44391
A djustin g the eng ine idlin g
spee d
The engine idling speed must be ad-
justed when necessary.
1. Start the engine and thoroughly warm it up.
2. Turn the throttle stop screw until the engine runs at the lowest pos-
sible speed.
3. To increase the engine idling speed, turn the throttle stop screw
in direction (a). To decrease the
engine idling speed, turn the throt-
tle stop screw in direction (b).
EAU48434
Adjustin g the throttle grip free
play
Measure the throttle grip free play as
shown.
Periodically check the throttle grip free
play and, if necessary, adjust it as fol-
lows.
TIP
The engine idling speed must be cor-
rectly adjusted before checking and
adjusting the throttle grip free play.
1. Slide the rubber cover back.
2. Loosen the locknut.
3. To increase the throttle grip free
play, turn the adjusting nut in di-
rection (a). To decrease the throt-
tle grip free play, turn the adjusting
nut in direction (b).
1. Throttle stop screw
1. Throttle grip free play
Throttle grip free play:
3.0–6.0 mm (0.12–0.24 in)
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Periodic maintenance an d a djustment
7-14
7 4. Tighten the locknut and then slide
the rubber cover to its original po-
sition.
EAU65042
Tires
Tires are the only contact between the
vehicle and the road. Safety in all con-
ditions of riding depends on a relatively
small area of road contact. Therefore, it
is essential to maintain the tires in good
condition at all times and replace them
at the appropriate time with the speci-
fied tires.
Tire air pressure
The tire air pressure should be
checked and, if necessary, adjusted
before each ride.
WARNING
EWA14382
Operation of this vehicle with im-
proper tire pressure may cause se-
vere injury or d eath from loss of
control.  The tire air pressure must be
checked and a djuste d on col d
tires (i.e., when the temperature
of the tires equals the am bient
temperature).
 The tire air pressure must be
a d juste d in accor dance with the
wei ght of the ri der, the rid ing
speed , and the ri din g con di-
tions.
1. Locknut
2. Throttle grip free play adjusting nut
3. Rubber cover
1 2
3
(a)
(b)
Standar d tire air pressure:
Front: 100 kPa (1.00 kgf/cm², 15 psi)
Rear:
100 kPa (1.00 kgf/cm², 15 psi)
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Periodic maintenance an d a djustment
7-15
7
Tire inspection
The tires must be checked before each
ride.
NOTICE
ECA15582

Make sure the bead stopper is
ti g htene d. A loose b ead stopper
will cause the tire to slip off the
rim if tire pressure is too low.
 Make sure the valve stem is po-
sitione d straig ht. A tilte d valve
stem in dicates that the tire has
slippe d from its ori ginal position
on the rim. Rotate the tire so
that the valve stem is positioned
straig ht.
If the center tread depth reaches the
specified limit, if the tire has a nail or
glass fragments in it, or if the sidewall
is cracked, have a Yamaha dealer re-
place the tire immediately.
Tire information
This model is equipped with tube tires. Tires age, even if they have not been
used or have only been used occasion-
ally. Cracking of the tread and sidewall
rubber, sometimes accompanied by
carcass deformation, is an evidence of
ageing. Old and aged tires shall be
checked by tire specialists to ascertain
their suitability for further use.
WARNING
EWA10462
The front an
d rear tires shoul d b e of
the same make an d d esi gn, other-
wise the han dlin g characteristics of
the vehicle may b e different, which
coul d lea d to an acci dent.
After extensive tests, only the tires list-
ed below have been approved for this
model by Yamaha.
WARNING
EWA14391
 Have a Yamaha dealer replace
excessively worn tires. Operat-
in g the motorcycle with exces-
sively worn tires decreases
ri din g sta bility an d can lead to
loss of control.
1. Tire sidewall
2. Tire tread depth
Minimum tire trea d d epth (front an d
rear):
4.0 mm (0.16 in)
1
2
Front tire:Size:
70/100-17 40M (YZ85, YZ85M)
70/100-19 42M (YZ85LW,
YZ85LWM)
Manufacturer/model: DUNLOP/MX3SF
Rear tire:
Size: 90/100-14 49M (YZ85, YZ85M)
90/100-16 52M (YZ85LW,
YZ85LWM)
Manufacturer/model: DUNLOP/MX3S
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Periodic maintenance an d a djustment
7-16
7 
The replacement of all wheel-
and b rake-relate d parts, inclu d-
in g the tires, shoul d b e left to a
Yamaha dealer, who has the
necessary professional knowl-
e dge an d experience.
 It is not recommen ded to patch
a punctured tube. If unavoi d-
a b le, however, patch the tu be
very carefully an d replace it as
soon as possi ble with a hi gh-
quality pro duct.
EAU48322
Spoke wheels
WARNING
EWA10611
The wheels on this mod el are not
d esi gne d for use with tu beless tires.
Do not attempt to use tu beless tires
on this mod el.
To maximize the performance, durabil-
ity, and safe operation of your motor-
cycle, note the following points
regarding the specified wheels.
 The wheel rims should be
checked for cracks, bends, warp-
age or other damage and the
spokes for looseness or damage
before each ride. If any damage is
found, have a Yamaha dealer re-
place the wheel. Do not attempt
even the smallest repair to the
wheel. A deformed or cracked
wheel must be replaced.
 The wheel should be balanced
whenever either the tire or wheel
has been changed or replaced. An
unbalanced wheel can result in
poor performance, adverse han-
dling characteristics, and a short-
ened tire life.
UB4B82E0.book Page 16 Wednesday, March 11, 2020 1:10 PM