engine YAMAHA TW125 2003 Owner's Manual

6-10
PERIODIC MAINTENANCE AND MINOR REPAIR
6
1
1. Engine oil drain bolt
ECA00039
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When removing the engine oil
drain bolt, the O-ring, compression
spring, and oil strainer will fall out.
Take care not to lose these parts.
12 3
1. Strainer
2. Compression spring
3. O-ring
NOTE:
Skip steps 4–9 if the oil filter element
is not being cleaned.
4. Remove the oil filter element
drain bolt to drain the oil from the
oil filter element.
5. Remove the oil filter element
cover by removing the bolts.
1
2
3
1. Oil filter element drain bolt
2. Oil filter element cover
3. Oil filter element cover bolt (×2)
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PERIODIC MAINTENANCE AND MINOR REPAIR
66. Remove the oil filter element and
O-rings.
7. Check the O-ring for damage
and replace it if necessary.
8. Clean the oil filter element with
solvent, and then install it.
NOTE:
Check the oil filter element for dam-
age and replace it if necessary.
9. Install the oil filter element cover
by installing the bolts and the
drain bolt, then tightening them
to the specified torques.
1 22
1. Oil filter element
2. O-ring (×2)
NOTE:
Make sure that the O-rings are prop-
erly seated.
10. Clean the oil strainer with sol-
vent, and then check it for dam-
age and replace it if necessary.
11. Install the oil strainer, compres-
sion spring, O-ring and engine oil
drain bolt, and then tighten the
drain bolt to the specified torque.12. Add the specified amount of the
recommended engine oil, and
then install and tighten the oil
filler cap. Tightening torques:
Oil filter element cover bolt:
10 Nm (1.0 m·kgf)
Oil filter element drain bolt:
10 Nm (1.0 m·kgf)
Tightening torque:
Engine oil drain bolt:
43 Nm (4.3 m·kgf)
Recommended engine oil:
See page 8-1.
Oil quantity:
Without oil filter element
removal:
1.0 L
With oil filter element removal:
1.1 L
Total amount (dry engine):
1.3 L
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
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8In order to prevent clutch slip-
page (since the engine oil also
lubricates the clutch), do not
mix any chemical additives.
Do not use oils with a diesel
specification of “CD” or oils of
a higher quality than specified.
In addition, do not use oils
labeled “ENERGY CONSERV-
ING
II” or higher.
8Make sure that no foreign
material enters the crankcase.
13. Start the engine, and then let it
idle for several minutes while
checking it for oil leakage. If oil is
leaking, immediately turn the
engine off and check for the
cause.
14. Turn the engine off, and then
check the oil level and correct it if
necessary.
EAU04216
Cleaning the air filter
element and check hose
The air filter element should be
cleaned at the intervals specified in
the periodic maintenance and lubrica-
tion chart. Clean the air filter element
more frequently if you are riding in
unusually wet or dusty areas. In addi-
tion, the air filter check hose must be
frequently checked and cleaned if
necessary.
To clean the air filter element
1. Remove panel A. (See page 6-5
for panel removal and installation
procedures.)2. Remove the air filter case cover
by removing the screws.
1
2
2
1. Air filter case cover
2. Screw (×4)
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PERIODIC MAINTENANCE AND MINOR REPAIR
63. Pull the air filter element out.
4. Remove the sponge material
from the air filter element frame,
clean it with solvent, and then
squeeze the remaining solvent
out.
1
2
1. Sponge material
2. Air filter element frame
5. Apply oil of the recommended
type to the entire surface of the
sponge material, and then
squeeze the excess oil out.
NOTE:
The sponge material should be wet
but not dripping.
6. Pull the sponge material over the
air filter element frame.
7. Insert the element into the air fil-
ter case.
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8Make sure that the air filter ele-
ment is properly seated in the
air filter case.
8The engine should never be
operated without the air filter
element installed, otherwise
the piston and/or cylinder may
become excessively worn.
8. Install the air filter case cover by
installing the screws.
9. Install the panel.
Recommended oil:
Engine oil
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PERIODIC MAINTENANCE AND MINOR REPAIR
6 To clean the air filter check hose
1. Check the hose at the bottom of
the air filter case for accumulated
dirt or water.
2. If dirt or water is visible, remove
the hose, clean it, and then
install it.
1
1. Air filter check hose
EAU00629
Adjusting the carburetor
The carburetor is an important part of
the engine and requires very sophisti-
cated adjustment. Therefore, most
carburetor adjustments should be left
to a Yamaha dealer, who has the
necessary professional knowledge
and experience. The adjustment
described in the following section,
however, may be serviced by the
owner as part of routine mainte-
nance.
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The carburetor has been set and
extensively tested at the Yamaha
factory. Changing these settings
without sufficient technical knowl-
edge may result in poor perfor-
mance of or damage to the engine.
EAU04757
Adjusting the engine idling
speed
The engine idling speed must be
checked and, if necessary, adjusted
as follows at the intervals specified in
the periodic maintenance and lubrica-
tion chart.
The engine should be warm before
making this adjustment.
NOTE:
8The engine is warm when it
quickly responds to the throttle.
8A diagnostic tachometer is need-
ed to make this adjustment.
1. Attach the tachometer to the
spark plug lead.
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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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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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w
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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PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU04369
To adjust the drive chain slack
1. Loosen the brake pedal free play
adjusting nut.
2. Loosen the axle nut.
3. To tighten the drive chain, turn
the adjusting plate on each side
of the swingarm in direction a.
To loosen the drive chain, turn
the adjusting plate on each side
of the swingarm in direction b,
and then push the rear wheel for-
ward.
32
a
b
1
1. Brake pedal free play adjusting nut
2. Axle nut
3. Drive chain adjusting plate
NOTE:
Make sure that both adjusting plates
are in the same position for proper
wheel alignment.
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Improper drive chain slack will
overload 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.
4. Tighten the axle nut to the speci-
fied torque.5. Adjust the brake pedal free play.
(See page 6-21 for brake pedal
free play adjustment proce-
dures.)
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w
After adjusting the brake pedal
free play, check the operation of
the brake light.
Tightening torque:
Axle nut:
90 Nm (9.0 m·kgf)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU01106
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.
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The drive chain must be lubricated
after washing the motorcycle or
riding in the rain.
1. Remove all dirt and mud from
the drive chain with a brush or
cloth.
2. Spray a drive chain lubricant on
both sides and on the middle of
the chain, making sure that all
side plates and rollers have been
sufficiently oiled.
NOTE:
For a thorough cleaning, have a
Yamaha dealer remove the drive
chain and soak it in solvent.
EAU02962
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 cables and cable ends
should be lubricated if necessary. If
a cable is damaged or does not move
smoothly, have a Yamaha dealer
check or replace it.
Recommended lubricant:
Engine oil
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00794
Checking the steering
Worn or loose steering bearings may
cause danger. Therefore, the opera-
tion of the steering must be checked
as follows at the intervals specified in
the periodic maintenance and lubrica-
tion chart.
1. Place a stand under the engine
to raise the front wheel off the
ground.
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w
Securely support the motorcycle
so that there is no danger of it
falling over.
2. Hold the lower ends of the front
fork legs and try to move them
forward and backward. If any
free play can be felt, have a
Yamaha dealer check or repair
the steering.
EAU01144
Checking the wheel bearings
The front and rear wheel bearings
must be checked at the intervals
specified in the periodic maintenance
and lubrication 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.
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