YAMAHA MT-03 2020 Repair Manual

Periodic maintenance and adjustment
6-17
6
TIP
The tire tread depth limits may differ
from country to country. Always com-
ply with the local regulations.
WARNING
EWA10472
Have a Yamaha dealer replace
excessively worn tires. Besides
being illegal, operating the vehi-
cle with excessively worn tires
decreases riding stability and
can lead to loss of control.
The replacement of all wheel
and brake-related parts, includ-
ing the tires, should be left to a
Yamaha dealer, who has the
necessary professional knowl-
edge and experience to do so.
Ride at moderate speeds after
changing a tire since the tire
surface must first be “broken
in” for it to develop its optimal
characteristics.
Tire information
This model is equipped with tubeless
tires and rubber tire air valves.
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 and rear tires should be of
the same make and design, other-
wise the handling characteristics of
the vehicle may be different, which
could lead to an accident.
After extensive tests, only the tires list-
ed below have been approved for this
model by Yamaha.
Minimum tire tread depth (front and
rear):
1.6 mm (0.06 in)
Front tire:
Size:
110/70R-17M/C 54H
Manufacturer/model:
DUNLOP/GPR-300F
Rear tire:
Size:
140/70R-17M/C 66H
Manufacturer/model:
DUNLOP/GPR-300
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Periodic maintenance and adjustment
6-18
6
EAU21963
Cast wheels
To maximize the performance, durabil-
ity, and safe operation of your vehicle,
note the following points regarding the
specified wheels.
The wheel rims should be
checked for cracks, bends, warp-
age or other damage before each
ride. If any damage is found, have
a Yamaha dealer replace the
wheel. Do not attempt even the
smallest repair to the wheel. A de-
formed 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.
EAU33893
Adjusting 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 as fol-
lows.
To increase the clutch lever free play,
turn the clutch lever free play adjusting
bolt at the clutch lever in direction (a).
To decrease the clutch lever free play,
turn the adjusting bolt in direction (b).
TIP
If the specified clutch lever free play
cannot be obtained as described
above, proceed as follows.
1. Fully turn the adjusting bolt at the
clutch lever in direction (a) to loos-
en the clutch cable.
2. Loosen the locknut at the crank-
case.
1. Clutch lever free play adjusting bolt
2. Locknut
3. Clutch lever free play
Clutch lever free play:
10.0–15.0 mm (0.39–0.59 in)
321
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Periodic maintenance and adjustment
6-19
6 3. To increase the clutch lever free
play, turn the clutch lever free play
adjusting nut in direction (a). To
decrease the clutch lever free
play, turn the adjusting nut in di-
rection (b).
4. Tighten the locknut.
EAU37914
Checking 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 spongy feeling in the brake
lever can indicate the presence of
air in the hydraulic system. If there is
air in the hydraulic system, have a
Yamaha dealer bleed the system be-
fore operating the vehicle. Air in the
hydraulic system will diminish the
braking performance, which may re-
sult in loss of control and an acci-
dent.
1. Locknut
2. Clutch lever free play adjusting nut
2
(b)
(a) 1
1. No brake lever free play
1
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Periodic maintenance and adjustment
6-20
6
EAU36505
Brake light switches
The brake light should come on just
before braking takes effect. The brake
light is activated by switches connect-
ed to the brake lever and brake pedal.
Since the brake light switches are
components of the anti-lock brake sys-
tem, they should only be serviced by a
Yamaha dealer.
EAU22393
Checking the front and rear
brake pads
The front and rear brake pads must be
checked for wear at the intervals spec-
ified in the periodic maintenance and
lubrication chart.
EAU22433Front brake pads
Each front 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 the wear
indicator grooves have almost disap-
peared, have a Yamaha dealer replace
the brake pads as a set.
1. Brake pad wear indicator groove
1
1
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Periodic maintenance and adjustment
6-21
6
EAU36721Rear brake pads
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 the wear
indicator grooves have almost disap-
peared, have a Yamaha dealer replace
the brake pads as a set.EAU22583
Checking the brake fluid 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 fluid may damage painted
surfaces or plastic parts. Always
clean up spilled fluid immediately.
Front brake
Rear brake
As the brake pads wear, it is normal for
the brake fluid level to gradually go
down.
1. Brake pad wear indicator groove
1
1Specified brake fluid:
DOT 4
1. Minimum level mark
1. Minimum level mark
1
1
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Periodic maintenance and adjustment
6-22
6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 braking ability. Observe
these precautions:
Insufficient brake fluid may al-
low air to enter the brake sys-
tem, reducing braking
performance.
Clean the filler cap before re-
moving. Use only DOT 4 brake
fluid from a sealed container.
Use only the specified brake flu-
id; otherwise, the rubber seals
may deteriorate, causing leak-
age.
Refill with the same type of
brake fluid. Adding a brake fluid
other than DOT 4 may result in a
harmful chemical reaction.
Be careful that water does not
enter the brake fluid reservoir
when refilling. Water will signifi-
cantly lower the boiling point of
the fluid and may result in vapor
lock.
EAU22734
Changing the brake fluid
Have a Yamaha dealer change the
brake fluid every 2 years. In addition,
have the seals of the master cylinders
and brake calipers, as well as the brake
hoses replaced at the intervals listed
below or sooner if they are damaged or
leaking.
Brake seals: every 2 years
Brake hoses: every 4 years
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Periodic maintenance and adjustment
6-23
6
EAU22762
Drive chain slack
The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU74253To check the drive chain slack
1. Place the motorcycle on the side-
stand.
TIP
When checking and adjusting the drive
chain slack, there should be no weight
on the motorcycle.
2. Shift the transmission into the
neutral position.
3. Measure the drive chain slack as
shown.
4. 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 and can lead to chain slip-
page or breakage. To prevent
this from occurring, keep the
drive chain slack within the
specified limits.
[ECA10572]EAU62983
To adjust the drive chain slack
Consult a Yamaha dealer before ad-
justing the drive chain slack.
1. Remove the drive chain puller cap,
and then loosen the axle nut and
the locknut on each side of the
swingarm.
2. To tighten the drive chain, turn the
drive chain slack adjusting nut on
each side of the swingarm in di-
rection (a). To loosen the drive
chain, turn the adjusting nut on
each side of the swingarm in di-
rection (b), and then push the rear
wheel forward.
1. Drive chain slack
Drive chain slack:
35.0–45.0 mm (1.38–1.77 in)
1
1. Axle nut
2. Locknut
3. Drive chain puller cap
1. Drive chain slack adjusting nut
2
3
1
1(a)
(b)
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Periodic maintenance and adjustment
6-24
6
TIP
Using the alignment marks on each
side of the swingarm, make sure that
both drive chain pullers are in the same
position for proper wheel alignment.
3. Tighten the axle nut, then the lock-
nuts to their 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.
5. Install the drive chain puller caps.
EAU23026
Cleaning and lubricating the
drive chain
The drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrica-
tion chart, otherwise it will quickly wear
out, especially when riding in dusty or
wet areas. Service the drive chain as
follows.
NOTICE
ECA10584
The drive chain must be lubricated
after washing the motorcycle, riding
in the rain or riding in wet areas.
1. Clean the drive chain with kero-
sene and a small soft brush.
NOTICE: To prevent damaging
the O-rings, do not clean the
drive chain with steam cleaners,
high-pressure washers or inap-
propriate solvents.
[ECA11122]
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive
chain with a special O-ring chain
lubricant. NOTICE: Do not use
engine oil or any other lubri-
cants for the drive chain, as they
may contain substances that
could damage the O-rings.
[ECA11112]
1. Alignment marks
2. Drive chain puller
Tightening torques:
Axle nut:
57 N·m (5.7 kgf·m, 42 lb·ft)
Locknut:
16 N·m (1.6 kgf·m, 12 lb·ft)
1 2
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Periodic maintenance and adjustment
6-25
6
EAU23098
Checking and lubricating the
cables
The operation of all control cables and
the condition of the cables should be
checked before each ride, and the ca-
bles and cable ends should be lubri-
cated if necessary. If a cable is
damaged or does not move smoothly,
have a Yamaha dealer check or re-
place it. WARNING! Damage to the
outer housing of cables may result
in internal rusting and cause inter-
ference with cable movement. Re-
place damaged cables as soon as
possible to prevent unsafe condi-
tions.
[EWA10712]EAU49921
Checking and lubricating the
throttle grip and cable
The operation of the throttle grip
should be checked before each ride. In
addition, the cable should be lubricat-
ed by a Yamaha dealer at the intervals
specified in the periodic maintenance
chart.
Recommended lubricant:
Yamaha cable lubricant or other
suitable cable lubricant
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Periodic maintenance and adjustment
6-26
6
EAU44276
Checking and lubricating the
brake and shift pedals
The operation of the brake and shift
pedals should be checked before each
ride, and the pedal pivots should be lu-
bricated if necessary.
Brake pedal
Shift pedal
EAU23144
Checking and lubricating the
brake and clutch levers
The operation of the brake and clutch
levers should be checked before each
ride, and the lever pivots should be lu-
bricated if necessary.
Brake lever
Clutch lever
Recommended lubricant:
Lithium-soap-based greaseRecommended lubricants:
Brake lever:
Silicone grease
Clutch lever:
Lithium-soap-based grease
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