YAMAHA MT-25 2016 Repair Manual

Periodic maintenance and adjustment
6-18
6
TIPIf 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.
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
playThere 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 thebraking 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
6-19
6
EAU22274
Brake light switchesThe brake light, which is activated by
the brake pedal and brake lever,
should come on just before braking
takes effect. If necessary, adjust the
rear brake light switch as follows, but
the front brake light switch should be
adjusted by a Yamaha dealer.
Turn the rear brake light switch adjust-
ing nut while holding the rear brake
light switch in place. To make the
brake light come on earlier, turn the ad-
justing nut in direction (a). To make the
brake light come on later, turn the ad-
justing nut in direction (b).
EAU22393
Checking the front and rear
brake padsThe front and rear brake pads must be
checked for wear at the intervals spec-
ified in the periodic maintenance and
lubrication chart.
EAU22432
Front 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 wearindicator grooves have almost disap-
peared, have a Yamaha dealer replace
the brake pads as a set.
EAU36721
Rear 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.
1. Rear brake light switch
2. Rear brake light switch adjusting nut
(a)
(b)1
2
1. Brake pad wear indicator groove
1 1
1. Brake pad wear indicator groove
1
1
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Periodic maintenance and adjustment
6-20
6
EAU22582
Checking the brake fluid levelBefore riding, check that the brake fluid
is above the minimum level mark.
Check the brake fluid level with the top
of the reservoir level. Replenish the
brake fluid if necessary.
Front brakeRear brake
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.
NOTICE
ECA17641
Brake fluid may damage painted
surfaces or plastic parts. Always
clean up spilled fluid immediately.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 and/or brake
system leakage; therefore, be sure to
check the brake pads for wear and the
brake system for leakage. If the brake
1. Minimum level mark
1
1. Minimum level mark
Specified brake fluid:
DOT 4
1
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Periodic maintenance and adjustment
6-21
6fluid level goes down suddenly, have a
Yamaha dealer check the cause before
further riding.
EAU22733
Changing the brake fluidHave 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 slackThe drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU22779
To check the drive chain slack
1. Place the motorcycle on the side-
stand.TIPWhen 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.Drive chain slack:
35.0–45.0 mm (1.38–1.77 in)
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Periodic maintenance and adjustment
6-22
6 4. If the drive chain slack is incorrect,
adjust it as follows.
EAU62982
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. NOTICE: Improp-
er drive chain slack will over-
load the engine as well as other
vital parts of the motorcycle and
can lead to chain slippage or
breakage. To prevent this from
occurring, keep the drive chain
slack within the specified limits.
[ECA10572]
TIPUsing 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.
1. Drive chain slack
1
1. Locknut
2. Drive chain puller cap
1. Axle nut
12
1
1. Drive chain slack adjusting nut
1
(a)(b)
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Periodic maintenance and adjustment
6-23
63. 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 chainThe 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 theymay contain substances that
could damage the O-rings.
[ECA11112]
1. Alignment marks
2. Drive chain pullerTightening torques:
Axle nut:
57 Nm (5.7 m·kgf, 41 ft·lbf)
Locknut:
16 Nm (1.6 m·kgf, 12 ft·lbf)
1 2
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Periodic maintenance and adjustment
6-24
6
EAU23098
Checking and lubricating the
cablesThe 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 cableThe 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.
EAU44276
Checking and lubricating the
brake and shift pedalsThe 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
Recommended lubricant:
Yamaha cable lubricant or other
suitable cable lubricant
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Periodic maintenance and adjustment
6-25
6
EAU23144
Checking and lubricating the
brake and clutch leversThe 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 grease
Recommended lubricants:
Brake lever:
Silicone grease
Clutch lever:
Lithium-soap-based grease
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Periodic maintenance and adjustment
6-26
6
EAU23203
Checking and lubricating the
sidestandThe operation of the sidestand should
be checked before each ride, and the
sidestand pivot and metal-to-metal
contact surfaces should be lubricated
if necessary.
WARNING
EWA10732
If the sidestand does not move up
and down smoothly, have a Yamaha
dealer check or repair it. Otherwise,
the sidestand could contact the
ground and distract the operator, re-
sulting in a possible loss of control.
EAUM1653
Lubricating the swingarm piv-
otsThe swingarm pivots must be lubricat-
ed by a Yamaha dealer at the intervals
specified in the periodic maintenance
and lubrication chart.
EAU23273
Checking the front forkThe condition and operation of the
front fork must be checked as follows
at the intervals specified in the periodic
maintenance and lubrication chart.
To check the condition
Check the inner tubes for scratches,
damage and excessive oil leakage.
To check the operation
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion. WARNING! To avoid injury,
securely support the vehicle so
there is no danger of it falling
over.
[EWA10752]
2. While applying the front brake,
push down hard on the handle-
bars several times to check if the
front fork compresses and re-
bounds smoothly.
Recommended lubricant:
Lithium-soap-based grease
Recommended lubricant:
Lithium-soap-based grease
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Periodic maintenance and adjustment
6-27
6
NOTICE
ECA10591
If any damage is found or the front
fork does not operate smoothly,
have a Yamaha dealer check or re-
pair it.
EAU23285
Checking the steeringWorn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as fol-
lows at the intervals specified in the
periodic maintenance and lubrication
chart.
1. Raise the front wheel off the
ground. (See page 6-33.)
WARNING! To avoid injury, se-
curely support the vehicle so
there is no danger of it falling
over.
[EWA10752]
2. Hold the lower ends of the front
fork legs and try to move them for-
ward and backward. If any free
play can be felt, have a Yamaha
dealer check or repair the steer-
ing.
EAU23292
Checking the wheel bearingsThe front and rear wheel bearings must
be checked at the intervals specified in
the periodic maintenance and lubrica-
tion chart. If there is play in the wheel
hub or if the wheel does not turn
smoothly, have a Yamaha dealer
check the wheel bearings.
UB04E0E0.book Page 27 Wednesday, September 2, 2015 3:51 PM