2003 YAMAHA TW125 maintenance

6-15
PERIODIC MAINTENANCE AND MINOR REPAIR
62. Check the engine idling speed
and, if necessary, adjust it to
specification by turning the throt-
tle stop screw. To increase the
engine idling speed, turn the
screw in direction a. To
decrease the engine idling
speed, turn the screw in direction
b.
1
ab
1. Throttle stop screw
NOTE:
If the specified idling speed cannot
be obtained as described above,
have a Yamaha dealer make the
adjustment.
EAU00635
Adjusting the throttle cable
free play
The throttle cable free play should
measure 3–5 mm at the throttle grip.
Periodically check the throttle cable
free play and, if necessary, have a
Yamaha dealer adjust it.
a
a. Throttle cable free play
Engine idling speed:
1,450–1,650 r/min
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6-16
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00637
Adjusting the valve
clearance
The valve clearance changes with
use, resulting in improper air-fuel mix-
ture and/or engine noise. To prevent
this from occurring, the valve clear-
ance must be adjusted by a Yamaha
dealer at the intervals specified in the
periodic maintenance and lubrication
chart.
EAU04401
Tires
To maximize the performance, dura-
bility, and safe operation of your
motorcycle, note the following points
regarding the specified tires.
Tire air pressure
The tire air pressure should be
checked and, if necessary, adjusted
before each ride.
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8The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the tempera-
ture of the tires equals the
ambient temperature).
8The tire air pressure must be
adjusted in accordance with
the riding speed and with the
total weight of rider, passen-
ger, cargo, and accessories
approved for this model.
Tire air pressure
(measured on cold tires)
Load* Front Rear
Up to 90 kg150 kPa
(1.50 kgf/cm
2,
1.50 bar)150 kPa
(1.50 kgf/cm2,
1.50 bar)
90 kg–maximum150 kPa
(1.50 kgf/cm
2,
1.50 bar)175 kPa
(1.75 kgf/cm2,
1.75 bar)
Maximum load* 180 kg
* Total weight of rider, passenger, cargo and
accessories
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6-17
PERIODIC MAINTENANCE AND MINOR REPAIR
6
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Because loading has an enormous
impact on the handling, braking,
performance and safety character-
istics of your motorcycle, you
should keep the following precau-
tions in mind.
8NEVER OVERLOAD THE
MOTORCYCLE! Operation of
an overloaded motorcycle may
result in tire damage, loss of
control, or severe injury. Make
sure that the total weight of
rider, passenger, cargo, and
accessories does not exceed
the specified maximum load
for the vehicle.
8Do not carry along loosely
packed items, which can shift
during a ride.
8Securely pack the heaviest
items close to the center of the
motorcycle and distribute the
weight evenly on both sides.8Adjust the tire air pressure
with regard to the load.
8Check the tire condition and
air pressure before each ride.
Tire inspection
The tires must be checked before
each ride. 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 replace the tire imme-
diately.
NOTE:
The tire tread depth limits may differ
from country to country. Always com-
ply with the local regulations.
1a
1. Tire side wall
a. Tire tread depth
Minimum tire tread depth
(front and rear)1.6 mm
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6-18
PERIODIC MAINTENANCE AND MINOR REPAIR
6 Tire information
This motorcycle is equipped with tube
tires.
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8The front and rear tires should
be of the same make and
design, otherwise the handling
characteristics of the motorcy-
cle cannot be guaranteed.
8After extensive tests, only the
tires listed below have been
approved for this model by
Yamaha Motor Co., Ltd.
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8Have a Yamaha dealer replace
excessively worn tires.
Besides being illegal, operat-
ing the motorcycle with exces-
sively worn tires decreases
riding stability and can lead to
loss of control.
8The replacement of all wheel-
and brake-related parts,
including the tires, should be
left to a Yamaha dealer, who
has the necessary profession-
al knowledge and experience.
8It is not recommended to
patch a punctured tube. If
unavoidable, however, patch
the tube very carefully and
replace it as soon as possible
with a high-quality product.
EAU00685
Spoke wheels
To maximize the performance, dura-
bility, and safe operation of your
motorcycle, note the following points
regarding the specified wheels.
8The wheel rims should be
checked for cracks, bends or
warpage, and the spokes for
looseness or 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 deformed or
cracked wheel must be replaced.
8The wheel should be balanced
whenever either the tire or wheel
has been changed or replaced.
An unbalanced wheel can result
in poor performance, adverse
handling characteristics, and a
shortened tire life.
FRONT
Manufacturer Size Type
BRIDGESTONE130/80-18 M/C 66P TW-203
REAR
Manufacturer Size Type
BRIDGESTONE180/80-14 M/C 78P TW-204
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6-19
PERIODIC MAINTENANCE AND MINOR REPAIR
68Ride at moderate speeds after
changing a tire since the tire sur-
face must first be “broken in” for
it to develop its optimal charac-
teristics.
EAU00694
Adjusting the clutch lever
free play
The clutch lever free play should
measure 10–15 mm as shown.
Periodically check the clutch lever
free play and, if necessary, adjust it
as follows.
1. Loosen the locknut at the clutch
lever.
2. To increase the clutch lever free
play, turn the adjusting bolt in
direction a. To decrease the
clutch lever free play, turn the
adjusting bolt in direction b.
c1
2
a
b
1. Locknut (clutch lever)
2. Adjusting bolt
c. Free play
3. If the specified clutch lever free
play could be obtained as
described above, tighten the
locknut and skip the rest of the
procedure, otherwise proceed as
follows.
4. Fully turn the adjusting bolt at the
clutch lever in direction ato
loosen the clutch cable.
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6-20
PERIODIC MAINTENANCE AND MINOR REPAIR
6 5. Loosen the locknut at the
crankcase.
6. To increase the clutch lever free
play, turn the adjusting nut in
direction a. To decrease the
clutch lever free play, turn the
adjusting nut in direction b.
7. Tighten the locknut at the clutch
lever and the crankcase.
21
ba
1. Locknut (crankcase)
2. Adjusting nut
EAU00696
Adjusting the brake lever
free play
The brake lever free play should
measure 5–8 mm as shown.
Periodically check the brake lever
free play and, if necessary, adjust it
as follows.
1. Loosen the locknut at the brake
lever.
2. To increase the brake lever free
play, turn the adjusting bolt in
direction a. To decrease the
brake lever free play, turn the
adjusting bolt in direction b.
c12
a
b
1. Locknut
2. Adjusting bolt
c. Free play
3. Tighten the locknut.EW000099
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8After adjusting the brake lever
free play, check the free play
and make sure that the brake
is working properly.
8A 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 before operating the
motorcycle. Air in the
hydraulic system will diminish
the braking performance,
which may result in loss of
control and an accident.
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6-21
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00707
Adjusting the brake pedal
position and free play
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It is advisable to have a Yamaha
dealer make these adjustments.
Brake pedal position
The top of the brake pedal should be
positioned approximately 30 mm
below the top of the footrest.
Periodically check the brake pedal
position and, if necessary, adjust it as
follows.
c
2 1
a
b
1. Locknut
2. Adjusting bolt
c. Brake pedal position
1. Loosen the locknut at the brake
pedal.
2. To raise the brake pedal, turn the
adjusting bolt in direction a. To
lower the brake pedal, turn the
adjusting bolt in direction b.
3. Tighten the locknut.
EWA00044
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After adjusting the brake pedal
position, the brake pedal free play
must be adjusted.
Brake pedal free play
The brake pedal free play should
measure 20–30 mm as shown.
Periodically check the brake pedal
free play and, if necessary, adjust it
as follows.
a
a. Brake pedal free play
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6-22
PERIODIC MAINTENANCE AND MINOR REPAIR
6 To increase the brake pedal free
play, turn the adjusting nut at the
brake rod in direction a. To
decrease the brake pedal free play,
turn the adjusting nut in direction b.
b
a1
1. Brake pedal free play adjusting nut
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8After adjusting the drive chain
slack or removing and
installing the rear wheel,
always check the brake pedal
free play.
8If proper adjustment cannot be
obtained as described, have a
Yamaha dealer make this
adjustment.
8After adjusting the brake pedal
free play, check the operation
of the brake light.
EAU00713
Adjusting the rear brake light
switch
The rear brake light switch, which is
activated by the brake pedal, is prop-
erly adjusted when the brake light
comes on just before braking takes
effect. If necessary, adjust the brake
light switch as follows.
Turn the adjusting nut while holding
the rear brake light switch in place.
To make the brake light come on ear-
lier, turn the adjusting nut in direction
a. To make the brake light come on
later, turn the adjusting nut in direc-
tion b.
1
2
a
b
1. Rear brake light switch
2. Adjusting nut
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