engine YAMAHA TW125 2000 User Guide

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OPERATION AND IMPORTANT RIDING POINTS
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EAU00373
w
8Before riding this motorcycle,
become thoroughly familiar
with all operating controls and
their functions. Consult a
Yamaha dealer regarding any
control or function that you do
not thoroughly understand.
8Never start your engine or let
it run for any length of time in
a closed area. The exhaust
fumes are poisonous and can
cause loss of consciousness
and death within a short time.
Always operate your motorcy-
cle in an area with adequate
ventilation.
8Before starting out, always be
sure the sidestand is up.
Failure to retract the sidestand
completely can result in a seri-
ous accident when you try to
turn a corner.
EAU03011Starting the engine
NOTE:
This motorcycle is equipped with
an ignition circuit cut-off system.
The engine can be started only
under one of the following condi-
tions:
8The transmission is in neutral.
8The sidestand is up, the trans-
mission is in gear and the
clutch is disengaged.
The motorcycle must not be ridden
when the sidestand is down.
EW000054
w
Before going through the follow-
ing steps, check the function of the
sidestand switch and clutch
switch. (Refer to page 3-12.)
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IF THE TRANSMISSION IS IN NEUTRAL AND
THE SIDESTAND IS DOWN, PUSH START
SWITCH.
THE ENGINE WILL START.
RETRACT THE SIDESTAND AND PUT THE
TRANSMISSION IN GEAR.
THE MOTORCYCLE CAN BE RIDDEN.THE MOTORCYCLE CAN BE RIDDEN.
IF THE TRANSMISSION IS IN GEAR AND THE
SIDESTAND IS UP, PULL IN THE CLUTCH
LEVER AND PUSH THE START SWITCH.
TURN THE MAIN SWITCH TO “ON” AND
THE ENGINE STOP SWITCH TO “#”.
THE ENGINE WILL START.
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9 1. Turn the fuel cock to “ON”.
2. Turn the main switch to “ON”
and the engine stop switch to
“#”.
3. Shift the transmission into
neutral.
NOTE:
When the transmission is in neu-
tral, the neutral indicator light
should be on. If the light does not
come on, ask a Yamaha dealer to
inspect it.
4. Turn on the starter (choke) and
completely close the throttle
grip.5. Start the engine by pushing
the start switch.
NOTE:
If the engine fails to start, release
the start switch, wait a few sec-
onds, then try again. Each attempt
should be as short as possible to
preserve the battery. Do not crank
the engine more than 10 seconds
on any one attempt.
6. After starting the engine, move
the starter (choke) to the
halfway position.
NOTE:
For maximum engine life, never
accelerate hard with a cold engine!
7. After warming up the engine,
turn off the starter (choke)
completely.
NOTE:
The engine is warm when it
responds normally to the throttle
with the starter (choke) turned off.
ONFUEL
RES
OFF
ON
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EAU01258Starting a warm engine
The starter (choke) is not required
when the engine is warm.
EC000046
cC
See the “Engine break-in” section
prior to operating the motorcycle
for the first time.
EC000048
cC
8Do not coast for long periods
with the engine off, and do
not tow the motorcycle a long
distance. Even with gears in
neutral, the transmission is
only properly lubricated when
the engine is running.
Inadequate lubrication may
damage the transmission.
8Always use the clutch when
changing gears. The engine,
transmission, and driveline are
not designed to withstand the
shock of forced shifting and
can be damaged by shifting
without using the clutch.
1
N5
4
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EAU00423Shifting
The transmission lets you control
the amount of power you have
available at a given speed for start-
ing, accelerating, climbing hills,
etc. The use of the shift pedal is
shown in the illustration.
To shift into neutral, depress the
shift pedal repeatedly until it reach-
es the end of its travel, then raise
the pedal slightly.
1. Shift pedal
N. Neutral
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EAU00424Tips for reducing fuel
consumption
Your motorcycle’s fuel consump-
tion depends to a large extent on
your riding style. The following
tips can help reduce fuel consump-
tion:
8Warm up the engine before
riding.
8Turn off the starter (choke) as
soon as possible.
8Shift up swiftly and avoid high
engine speeds during accelera-
tion.
8Do not double-clutch or rev the
engine while shifting down
and avoid high engine speeds
with no load on the engine.
8Turn off the engine instead of
letting it idle for an extended
length of time, i.e. in traffic
jams, at traffic lights or rail-
road crossings.
EAU01128Engine break-in
There is never a more important
period in the life of your motorcy-
cle than the period between zero
and 1,600 km. For this reason we
ask that you carefully read the fol-
lowing material. Because the
engine is brand new, you must not
put an excessive load on it for the
first 1,600 km. The various parts in
the engine wear and polish them-
selves to the correct operating
clearances. During this period, pro-
longed full throttle operation, or
any condition which might result in
excessive heating of the engine,
must be avoided.
EAU015000 ~ 1,000 km
Avoid operation above 1/3 throttle.
1,000 ~ 1,600 km
Avoid cruising speeds in excess of
1/2 throttle.
EC000057
cC
After 1,000 km of operation, be
sure to replace the engine oil and
clean the oil filter element and oil
strainer.
1,600 km and beyond
Proceed with normal riding.
EC000049
cC
If any engine trouble should occur
during the break-in period, consult
a Yamaha dealer immediately.
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RES
ONFUEL
OFF
EAU00457Parking
When parking the motorcycle, stop
the engine and remove the ignition
key. Turn the fuel cock to “OFF”
whenever stopping the engine.
EW000058
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The exhaust system is hot. Park
the motorcycle in a place where
pedestrians or children are not
likely to touch the motorcycle. Do
not park the motorcycle on a slope
or soft ground; the motorcycle
may overturn.
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*: Since these items require special tools, data and technical skills, they should be serviced by a Yamaha dealer.
EAU02970
NOTE:
8The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
8Hydraulic brake system
8When disassembling the master cylinder or caliper, always replace the brake fluid. Check the brake fluid
level regularly and fill as required.
8Replace the oil seals on the inner parts of the master cylinder and caliper every two years.
8Replace the brake hoses every four years or if cracked or damaged.
Every Every
6,000 km 12,000 km
No. ITEM CHECKS AND MAINTENANCE JOBSINITIAL or or
1,000 km 6 months 12 months
(Whichever (Whichever
comes first) comes first)
21 * Carburetor9Check engine idling speed and starter operation.
ÖÖÖ
9Adjust if necessary.
9Check oil level and vehicle for oil leakage.
22 Engine oil9Correct if necessary.ÖÖÖ
9Change. (Warm engine before draining.)
23Engine oil filter element9Clean or replace if necessary.ÖÖ
24 * Engine oil strainer9Clean or replace if necessary.ÖÖ
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EAU01833Spark plug
Removal
1. Remove the spark plug cap.
2. Use the spark plug wrench in
the tool kit to remove the spark
plug as shown.
1. Spark plug wrench
Inspection
The spark plug is an important
engine component and is easy to
inspect. The condition of the spark
plug can indicate the condition of
the engine.
The ideal color on the white insula-
tor around the center electrode is a
medium-to-light tan color for a
motorcycle that is being ridden
normally.
Do not attempt to diagnose such
problems yourself. Instead, take
the motorcycle to a Yamaha deal-
er. You should periodically remove
and inspect the spark plug because
heat and deposits will cause any
spark plug to slowly break down
and erode. If electrode erosion
becomes excessive, or if carbon
and other deposits are excessive,
you should replace the spark plug
with the specified plug.
Specified spark plug:
DR8EA (NGK)
12
1
EAU01145Cowling C
To remove
Remove the cowling screw and
pull outward on the areas shown.
To install
Place in the original position and
install the screw.
1. Cowling C
2. Screw
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Installation
1. Measure the electrode gap
with a wire thickness gauge
and, if necessary, adjust the
gap to specification.
2. Clean the gasket surface. Wipe
off any grime from the
threads.
3. Install the spark plug and tight-
en it to the specified torque.
1. Spark plug gap
NOTE:
If a torque wrench is not available
when you are installing a spark
plug, a good estimate of the cor-
rect torque is 1/4 to 1/2 turn past
finger tight. Have the spark plug
tightened to the specified torque as
soon as possible.
4. Install the spark plug cap.
EAU00517*
Engine oil
Oil level measurement
1. Place the motorcycle on a level
place and hold it in an upright
position. Warm up the engine
for several minutes.
NOTE:
Be sure the motorcycle is posi-
tioned straight up when checking
the oil level. A slight tilt toward the
side can result in false readings.
Spark plug gap:
0.6 ~ 0.7 mm
Tightening torque:
Spark plug:
17.5 Nm (1.75 m·kg)
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92. With the engine stopped,
check the oil level through the
level window located at the
lower part of the right side
crankcase cover.
NOTE:
Wait a few minutes until the oil
level settles before checking.
3. The oil level should be
between the maximum and
minimum marks. If the level is
low, add sufficient oil to raise
it to the proper level.
1. Maximum level mark
2. Minimum level mark
Engine oil replacement
1. Warm up the engine for a few
minutes.
2. Stop the engine. Place an oil
pan under the engine and
remove the oil filler cap.
1. Engine oil filler cap
3. Remove the drain bolts.
1. Engine oil drain bolt
1
1
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2
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