2003 YAMAHA TW125 fuel

4-1
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PRE-OPERATION CHECKS
4The condition of a vehicle is the owner’s responsibility. Vital components can start to deteriorate quickly and unexpect-
edly, even if the vehicle remains unused (for example, as a result of exposure to the elements). Any damage, fluid leak-
age or loss of tire air pressure could have serious consequences. Therefore, it is very important, in addition to a thor-
ough visual inspection, to check the following points before each ride.
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Pre-operation check listPre-operation check list
ITEM CHECKS PAGE
Fuel•Check fuel level in fuel tank.
•Refuel if necessary.
•Check fuel line for leakage.3-5–3-7
Engine oil•Check oil level in engine.
•If necessary, add recommended oil to specified level.
•Check vehicle for oil leakage.6-9–6-12
Front brake•Check operation.
•If soft or spongy, have Yamaha dealer bleed hydraulic system.
•Check lever free play.
•Adjust if necessary.
•Check fluid level in reservoir.
•If necessary, add recommended brake fluid to specified level.
•Check hydraulic system for leakage.3-5, 6-20, 6-23–6-25
Rear brake•Check operation.
•Check pedal free play.
•Adjust if necessary.3-5, 6-21–6-23
Clutch•Check operation.
•Lubricate cable if necessary.
•Check lever free play.
•Adjust if necessary.3-4, 6-19–6-20
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5-1
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OPERATION AND IMPORTANT RIDING POINTS
5
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8Become thoroughly familiar
with all operating controls and
their functions before riding.
Consult a Yamaha dealer
regarding any control or func-
tion that you do not thorough-
ly understand.
8Never start the engine or oper-
ate it in a closed area for any
length of time. Exhaust fumes
are poisonous, and inhaling
them can cause loss of con-
sciousness and death within a
short time. Always make sure
that there is adequate ventila-
tion.
8Before starting out, make sure
that the sidestand is up. If the
sidestand is not raised com-
pletely, it could contact the
ground and distract the opera-
tor, resulting in a possible loss
of control.
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Starting a cold engine
In order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:
8The transmission is in the neutral
position.
8The transmission is in gear with
the clutch lever pulled and the
sidestand up.
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8Before starting the engine,
check the function of the igni-
tion circuit cut-off system
according to the procedure
described on page 3-13.
8Never ride with the sidestand
down.
1. Turn the fuel cock lever to “ON”.
2. Turn the key to “ON” and make
sure that the engine stop switch
is set to “#”.
3. Shift the transmission into the
neutral position.
NOTE:
When the transmission is in the neu-
tral position, the neutral indicator light
should be on, otherwise have a
Yamaha dealer check the electrical
circuit.
ONFUEL
RES
OFF
1ON
1. Arrow mark positioned over “ON”
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5-4
OPERATION AND IMPORTANT RIDING POINTS
5
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Tips for reducing fuel
consumption
Fuel consumption depends largely on
your riding style. Consider the follow-
ing tips to reduce fuel consumption:
8Turn the starter (choke) off as
soon as possible.
8Shift up swiftly, and avoid high
engine speeds during accelera-
tion.
8Do not rev the engine while shift-
ing down, and avoid high engine
speeds with no load on the
engine.
8Turn the engine off instead of let-
ting it idle for an extended length
of time (e.g., in traffic jams, at
traffic lights or at railroad cross-
ings).
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Engine break-in
There is never a more important peri-
od in the life of your engine than the
period between 0 and 1,000 km. For
this reason, you should read the fol-
lowing material carefully.
Since the engine is brand new, do
not put an excessive load on it for the
first 1,000 km. The various parts in
the engine wear and polish them-
selves to the correct operating clear-
ances. During this period, prolonged
full-throttle operation or any condition
that might result in engine overheat-
ing must be avoided.
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0–500 km
Avoid prolonged operation above 1/3
throttle.
500–1,000 km
Avoid prolonged operation above 1/2
throttle.
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After 1,000 km of operation, the
engine oil must be changed, and
the oil filter element and the oil
strainer cleaned.
1,000 km and beyond
The vehicle can now be operated
normally.
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cC
If any engine trouble should occur
during the engine break-in period,
immediately have a Yamaha dealer
check the vehicle.
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5-5
OPERATION AND IMPORTANT RIDING POINTS
5
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Parking
When parking, stop the engine,
remove the key from the main switch,
and then turn the fuel cock lever to
“OFF”.
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8Since the engine and exhaust
system can become very hot,
park in a place where pedestri-
ans or children are not likely
to touch them.
8Do not park on a slope or on
soft ground, otherwise the
motorcycle may overturn.
RES
ONFUEL
OFF
1
1. Arrow mark positioned over “OFF”
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6-2
PERIODIC MAINTENANCE AND MINOR REPAIR
6
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Periodic maintenance and lubrication chartPeriodic maintenance and lubrication chart
NOTE:
8The annual checks must be performed every year, except if a kilometer-based maintenance is performed instead.
8From 30,000 km, repeat the maintenance intervals starting from 6,000 km.
8Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and
technical skills.
NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING (× 1,000 km)
ANNUAL
CHECK
1 6 12 18 24
1
*Fuel line•Check fuel hoses and vacuum hose for cracks or damage.√√√√ √
2 Spark plug•Check condition.
•Clean and regap.√√
•Replace.√√
3
*Valves•Check valve clearance.
•Adjust.√√√√
4 Air filter element•Clean.√√
•Replace.√√
5 Clutch•Check operation.
•Adjust.√√√√√
6
*Front brake•Check operation, fluid level and vehicle for fluid leakage.
(See NOTE on page 6-4.)√√√√√ √
•Replace brake pads.Whenever worn to the limit
7
*Rear brake•Check operation and adjust brake pedal free play.√√√√√ √
•Replace brake shoes.Whenever worn to the limit
8
*Brake hose•Check for cracks or damage.√√√√ √
•Replace. (See NOTE on page 6-4.)Every 4 years
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PERIODIC MAINTENANCE AND MINOR REPAIR
6
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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.
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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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6-42
PERIODIC MAINTENANCE AND MINOR REPAIR
6
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After adjusting the brake pedal
free play, check the operation of
the brake light.
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Troubleshooting
Although Yamaha motorcycles
receive a thorough inspection before
shipment from the factory, trouble
may occur during operation. Any
problem in the fuel, compression, or
ignition systems, for example, can
cause poor starting and loss of
power.
The following troubleshooting chart
represents a quick and easy proce-
dure for checking these vital systems
yourself. However, should your
motorcycle require any repair, take it
to a Yamaha dealer, whose skilled
technicians have the necessary tools,
experience, and know-how to service
the motorcycle properly.
Use only genuine Yamaha replace-
ment parts. Imitation parts may look
like Yamaha parts, but they are often
inferior, have a shorter service life
and can lead to expensive repair
bills.
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6-43
PERIODIC MAINTENANCE AND MINOR REPAIR
6
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Troubleshooting chartEW000125
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Keep away open flames and do not smoke while checking or working on the fuel system.
Check the fuel level in
the fuel tank.
1. FuelThere is enough fuel.
There is no fuel.Check the compression.
Supply fuel.
The engine does not start.
Check the compression.
Operate the electric starter.
2. CompressionThere is compression.
There is no compression.Check the ignition.
Have a Yamaha dealer
check the vehicle.
Remove the spark plug
and check the electrodes.
3. IgnitionWipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the vehicle.
The engine does not start.
Have a Yamaha dealer
check the vehicle.
The engine does not start.
Check the battery.
Operate the electric starter.
4. BatteryThe engine turns over
quickly.
The engine turns over
slowly.The battery is good.
Check the battery lead connections,
and charge the battery if necessary.
Dry
WetOpen the throttle halfway and operate
the electric starter.
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