YAMAHA YZ85 2020 Repair Manual

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 be 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, YZ85L)
70/100-19 42M (YZ85LW,
YZ85LWL)
Manufacturer/model: DUNLOP/MX3SF
Rear tire:
Size: 90/100-14 49M (YZ85, YZ85L)
90/100-16 52M (YZ85LW,
YZ85LWL)
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.
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Periodic maintenance an d a djustment
7-17
7
EAU65775
A djustin g the clutch lever free
play
Measure the clutch lever free play as
shown.
Periodically check the clutch lever free
play and, if necessary, adjust it.
To increase the clutch lever free play,
turn the clutch lever free play adjuster
in direction (a). To decrease the clutch
lever free play, turn the adjuster in di-
rection (b).
TIP
If the specified clutch lever free play
cannot be obtained as described
above, proceed as follows.
1. Fully turn the adjuster in direction
(a) to loosen the clutch cable.
2. Slide the rubber cover and clutch lever free play adjuster back fur-
ther down the clutch cable, and
then loosen the locknut.
3. To increase the clutch lever free play, turn the clutch lever free play
adjusting bolt in direction (a). To decrease the clutch lever free
play, turn the adjusting bolt in di-
rection (b).
4. Tighten the locknut at the clutch cable.
5. Slide the clutch lever free play ad- juster and rubber cover to their
original positions, making sure to
align the slot in the adjuster with
the slot in the adjusting bolt.
1. Clutch lever free play
2. Clutch lever free play adjuster
Clutch lever free play:7.0–12.0 mm (0.28–0.47 in)
2
1 (b)
(a)
1. Locknut
2. Clutch lever free play adjusting bolt
3. Clutch lever free play adjuster
4. Rubber cover
1. Slot
4
3
2
1
(b)
(a)
1
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Periodic maintenance an d a djustment
7-18
7
EAU37914
Checkin g the brake lever free
play
There should be no free play at the
brake lever end. If there is free play,
have a Yamaha dealer inspect the
brake system.
WARNING
EWA14212
A soft or spon gy feelin g in the b rake
lever can in dicate the presence of
air in the hy draulic system. If there is
air in the hy draulic system, have a
Yamaha dealer blee d the system be-
fore operatin g the vehicle. Air in the
hy draulic system will diminish the
b rakin g performance, which may re-
sult in loss of control and an acci-
d ent.
EAU44821
Checkin g the shift pe dal
The operation of the shift pedal should
be checked before each ride. If opera-
tion is not smooth, have a Yamaha
dealer check the vehicle.
1. No brake lever free play
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Periodic maintenance an d a djustment
7-19
7
EAU22393
Checkin g the front an d rear
b rake pa ds
The front and rear brake pads must be
checked for wear at the intervals spec-
ified in the periodic maintenance and
lubrication chart.
EAU22411Front brake pa ds
Each front brake pad is provided with a
wear indicator, which allows you to
check the brake pad wear without hav-
ing to disassemble the brake. To check
the brake pad wear, check the position
of the wear indicator while applying the
brake. If a brake pad has worn to the
point that the wear indicator almost
touches the brake disc, have a
Yamaha dealer replace the brake pads as a set.
EAU46292Rear brake pa ds
Each rear brake pad is provided with
wear indicator grooves, which allow
you to check the brake pad wear with-
out having to disassemble the brake.
To check the brake pad wear, check
the wear indicator grooves. If a brake
pad has worn to the point that a wear
indicator groove almost appears, have
a Yamaha dealer replace the brake
pads as a set.
1. Brake pad wear indicator
11. Brake pad wear indicator groove
1
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Periodic maintenance an d a djustment
7-20
7
EAU22583
Checkin g the brake flui d level
Before riding, check that the brake fluid
is above the minimum level mark.
Check the brake fluid level with the res-
ervoir in an upright position. Replenish
the brake fluid if necessary.
NOTICE
ECA17641
Brake flui d may damag e painte d
surfaces or plastic parts. Always
clean up spille d flui d imme diately.
Front brake
Rear brake
As the brake pads wear, it is normal for
the brake fluid level to gradually go
down. 
A low brake fluid level may indi-
cate worn brake pads or brake
system leakage; therefore, be sure
to check the brake pads for wear
and the brake system for leakage.
 If the brake fluid level goes down
suddenly, have a Yamaha dealer
check the cause before further rid-
ing.
WARNING
EWA15991
Improper maintenance can result in
loss of brakin g a bility. O bserve
these precautions:  Insufficient brake flui d may al-
low air to enter the brake sys-
tem, re ducing brakin g
performance.
 Clean the filler cap before re-
moving . Use only DOT 4 brake
flui d from a seale d container.
 Use only the specified b rake flu-
i d ; otherwise, the ru bber seals
may deteriorate, causin g leak-
a g e.
 Refill with the same type of
brake flui d. A ddin g a brake flui d
other than DOT 4 may result in a
harmful chemical reaction.
 Be careful that water d oes not
enter the b rake fluid reservoir
when refillin g. Water will si gnifi-
cantly lower the boilin g point of
the flui d an d may result in vapor
lock.
Specifie d b rake flui d:
DOT 4
1. Minimum level mark
1. Minimum level mark
1
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Periodic maintenance an d a djustment
7-21
7
EAU51721
Chan gin g the brake flui d
Have a Yamaha dealer change the
brake fluid at the intervals specified in
the periodic maintenance and lubrica-
tion chart. In addition, have the oil seals
of the master cylinders and calipers as
well as the brake hoses replaced at the
intervals listed below or whenever they
are damaged or leaking.
 Oil seals: Replace every two
years.
 Brake hoses: Replace every four
years.
EAU22762
Drive chain slack
The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU84400To check the d rive chain slack
1. Place the motorcycle on a suitable stand. (See page 7-28.)
2. Confirm the rear wheel is off the ground and the rear shock ab-
sorber is fully extended.
3. Shift the transmission into neutral.
4. Pull up the drive chain until the chain is taut, and then measure
distance A between the top of the
swingarm and the bottom of the
chain as shown.
5. If the drive chain slack is incorrect, adjust it as follows. NOTICE: Im-
proper drive chain slack will
overload the engine as well as
other vital parts of the motorcy-
cle an d can lead to chain slip-
pa ge or breakag e. To prevent
1. Distance A
Distance A:
58.0–68.0 mm (2.28–2.68 in) (YZ85,
YZ85L)
65.0–75.0 mm (2.56–2.95 in)
(YZ85LW, YZ85LWL)
1
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Periodic maintenance an d a djustment
7-22
7 this from occurrin
g, keep the
d rive chain slack within the
specifie d limits.
[ECA10572]
EAU84060
To adjust the drive chain slack
Consult a Yamaha dealer before ad-
justing the drive chain slack. 1. Loosen the axle nut and the lock- nut on each side of the swingarm.
2. To tighten the drive chain, turn the drive chain slack adjusting bolt on
each side of the swingarm in di-
rection (a). To loosen the drive
chain, turn the adjusting bolt on
each side of the swingarm in di-
rection (b), and then push the rear
wheel forward.
TIP
Using the alignment marks on the drive
chain pullers and the notch on each
side of the swingarm, make sure that
both drive chain pullers are in the same
position for proper wheel alignment.
3. Tighten both locknuts and the axlenut to the specified torques.
4. Make sure that the drive chain pullers are in the same position,
the drive chain slack is correct,
and the drive chain moves
smoothly.1. Axle nut
2. Locknut
1. Drive chain slack adjusting bolt
1
2
(b)
(a) 1
1. Notch
2. Alignment mark
3. Drive chain puller
Ti
ghtening torques:
Locknut: 21 N·m (2.1 kgf·m, 15 lb·ft)
Axle nut:
80 N·m (8.0 kgf·m, 59 lb·ft)
12
3
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