2003 YAMAHA TW125 engine

6-4
PERIODIC MAINTENANCE AND MINOR REPAIR
6EAU03541
NOTE:
8The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
8Hydraulic brake service
9Regularly check and, if necessary, correct the brake fluid level.
9Every two years replace the internal components of the brake master cylinder and caliper, and change the brake
fluid.
9Replace the brake hoses every four years and if cracked or damaged.
21*Carburetor•Check starter (choke) operation.
•Adjust engine idling speed.√√√√√ √
22 Engine oil•Change.
•Check oil level and vehicle for oil leakage.√√√√√ √
23 Engine oil filter element•Clean.√√√
24
*Engine oil strainer•Clean.√
25
*Front and rear brake
switches•Check operation.√√√√√ √
26 Moving parts and cables•Lubricate.√√√√ √
27
*Throttle grip housing
and cable•Check operation and free play.
•Adjust the throttle cable free play if necessary.
•Lubricate the throttle grip housing and cable.√√√√ √
28
*Lights, signals and
switches•Check operation.
•Adjust headlight beam.√√√√√ √ NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING (× 1,000 km)
ANNUAL
CHECK
1 6 12 18 24
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU01833
Checking the spark plug
The spark plug is an important
engine component, which is easy to
check. Since heat and deposits will
cause any spark plug to slowly erode,
the spark plug should be removed
and checked in accordance with the
periodic maintenance and lubrication
chart. In addition, the condition of the
spark plug can reveal the condition of
the engine.To remove the spark plug
1. Remove the spark plug cap.
1
1. Spark plug cap
2. Remove the spark plug as
shown, with the spark plug
wrench included in the owner’s
tool kit.
1
1. Spark plug wrench
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PERIODIC MAINTENANCE AND MINOR REPAIR
6 To check the spark plug
1. Check that the porcelain insula-
tor around the center electrode
of the spark plug is a medium-to-
light tan (the ideal color when the
motorcycle is ridden normally).
NOTE:
If the spark plug shows a distinctly
different color, the engine could be
defective. Do not attempt to diagnose
such problems yourself. Instead,
have a Yamaha dealer check the
motorcycle.
2. Check the spark plug for elec-
trode erosion and excessive car-
bon or other deposits, and
replace it if necessary.To install the spark plug
1. Measure the spark plug gap with
a wire thickness gauge and, if
necessary, adjust the gap to
specification.
2. Clean the surface of the spark
plug gasket and its mating sur-
face, and then wipe off any grime
from the spark plug threads.
3. Install the spark plug with the
spark plug wrench, and then
tighten it to the specified torque.
a
a. Spark plug gap
NOTE:
If a torque wrench is not available
when installing a spark plug, a good
estimate of the correct torque is
1/4–1/2 turn past finger tight.
However, the spark plug should be
tightened to the specified torque as
soon as possible.
4. Install the spark plug cap.
Spark plug gap:
0.6–0.7 mm
Tightening torque:
Spark plug:
17.5 Nm (1.75 m·kgf)
Specified spark plug:
DR8EA (NGK)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU04616
Engine oil and oil filter
element
The engine oil level should be
checked before each ride. In addition,
the oil must be changed and the oil
filter element cleaned at the intervals
specified in the periodic maintenance
and lubrication chart.
To check the engine oil level
1. Place the motorcycle on a level
surface and hold it in an upright
position.
NOTE:
Make sure that the motorcycle is
positioned straight up when checking
the oil level. A slight tilt to the side
can result in a false reading.
2. Start the engine, warm it up for
several minutes, and then turn it
off.3. Wait a few minutes until the oil
settles, and then check the oil
level through the check window
located at the bottom-right side
of the crankcase.
NOTE:
The engine oil should be between the
minimum and maximum level marks.
4. If the engine oil is below the min-
imum level mark, add sufficient
oil of the recommended type to
raise it to the correct level.
2
3 1
1. Engine oil level check window
2. Maximum level mark
3. Minimum level mark
To change the engine oil (with or
without oil filter element cleaning)
1. Start the engine, warm it up for
several minutes, and then turn it
off.
2. Place an oil pan under the
engine to collect the used oil.
3. Remove the engine oil filler cap
and drain bolt to drain the oil
from the crankcase.
1
1. Engine oil filler cap
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
1
1. Engine oil drain bolt
ECA00039
cC
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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cC
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.
EC000082
cC
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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