YAMAHA YZF-R125 2019 Repair Manual

Periodic maintenance and adjustment
6-18
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 informationThis model is equipped with tubeless
tires and 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
EWA16101
The front and rear tires should
be of the same make and de-
sign, otherwise the handling
characteristics of the vehicle
may be different, which could
lead to an accident.
Always make sure that the valve
caps are securely installed to
prevent air pressure leakage.
Use only the tire valves and
valve cores listed below to
avoid tire deflation during a ride.
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)
1. Tire air valve
2. Tire air valve core
3. Tire air valve cap with seal
123
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Periodic maintenance and adjustment
6-19
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.
Front tire:
Size:
100/80-17M/C 52S
Manufacturer/model:
MICHELIN PILOT STREET
Tire air valve:
TR412
Valve core:
V3002 (original)
Rear tire:
Size:
140/70-17M/C 66S
Manufacturer/model:
MICHELIN PILOT STREET
Tire air valve:
TR412
Valve core:
V3002 (original)
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Periodic maintenance and adjustment
6-20
6
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.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.
1. Clutch lever free play
2. Locknut
3. Clutch lever free play adjusting bolt
Clutch lever free play:
10.0–15.0 mm (0.39–0.59 in)
ZAUM1597
)
)3
2
1(a
(b
1. Clutch lever free play adjusting nut (crank-
case)
2. Locknut
ZAUM1598
2
(a)
(b)
1
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Periodic maintenance and adjustment
6-21
6
EAUT1223
Checking the front brake lever
free play
Measure the front brake lever free play
as shown.
Periodically check the brake lever free
play and, if necessary, have a Yamaha
dealer check the brake system.
WARNING
EWA10642
An incorrect brake lever free play in-
dicates a hazardous condition in the
brake system. Do not operate the
vehicle until the brake system has
been checked or repaired by a
Yamaha dealer.
EAUM1355
Adjusting the brake pedal free
play
Measure the brake pedal free play as
shown.
Periodically check the brake pedal free
play and, if necessary, have a Yamaha
dealer adjust it.
WARNING
EWAM1031
An incorrect brake pedal free play
indicates a hazardous condition in
the brake system. Do not operate
the motorcycle until the brake sys-
tem has been checked or repaired
by a Yamaha dealer.
1. Brake lever free play
Front brake lever free play:
2.0–5.0 mm (0.08–0.20 in)
ZAUM1599
1
1. Brake pedal free play
Brake pedal free play:
3.5–4.5 mm (0.14–0.18 in)
ZAUM1600
1
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Periodic maintenance and adjustment
6-22
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.
EAU22421Front brake pads
Each front brake pad is provided with a
wear indicator groove, which allows
you to check the brake pad wear with-
out having to disassemble the brake.
To check the brake pad wear, check
the wear indicator groove. If a brake
pad has worn to the point that the wear
indicator groove has almost disap-
peared, have a Yamaha dealer replace
the brake pads as a set.
1. Wear indicator groove
ZAUM1466
1
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Periodic maintenance and adjustment
6-23
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.EAU40262
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 top
of the reservoir level. Replenish the
brake fluid if necessary.
Front brake
Rear brake
WARNING
EWA16011
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.
1. Wear indicator groove
ZAUM1601
1
1
1. Minimum level mark
1. Minimum level mark
Specified brake fluid:
DOT 4
1
ZAUM1057
ZAUM1603
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Periodic maintenance and adjustment
6-24
6 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 or dust
does not enter the brake fluid
reservoir when refilling. Water
will significantly lower the boil-
ing point of the fluid and may re-
sult in vapor lock, and dirt may
clog the ABS hydraulic unit
valves.
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
fluid level goes down suddenly, have a
Yamaha dealer check the cause before
further riding.
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
6-25
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]EAU3431A
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. 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]
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.
1. Drive chain slack
Drive chain slack:
30.0–40.0 mm (1.18–1.57 in)
ZAUM1604
1
1. Drive chain slack adjusting bolt
2. Axle nut
3. Alignment marks
4. Locknut
ZAUM1605
3 21
4
(b) (a)
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Periodic maintenance and adjustment
6-26
6 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.
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]
Tightening torques:
Axle nut:
85 N·m (8.5 kgf·m, 63 lb·ft)
Locknut:
15 N·m (1.5 kgf·m, 11 lb·ft)
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Periodic maintenance and adjustment
6-27
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]EAU23115
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.
The throttle cable is equipped with a
rubber cover. Make sure that the cover
is securely installed. Even though the
cover is installed correctly, it does not
completely protect the cable from wa-
ter entry. Therefore, use care not to
pour water directly onto the cover or
cable when washing the vehicle. If the
cable or cover becomes dirty, wipe
clean with a moist cloth.
Recommended lubricant:
Yamaha cable lubricant or other
suitable cable lubricant
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