2004 YAMAHA TW125 engine

TABLE OF CONTENTS
SAFETY INFORMATION ............. 1-1
DESCRIPTION ............................. 2-1
Left view ..................................... 2-1
Right view................................... 2-2
Controls and instruments ........... 2-3
INSTRUMENT AND CONTROL
FUNCTIONS ................................. 3-1
Main switch ............................... 3-1
Indicator lights ........................... 3-1
Speedometer unit ...................... 3-2
Handlebar switches ................... 3-3
Clutch lever ............................... 3-4
Shift pedal ................................. 3-4
Brake lever ................................ 3-4
Brake pedal ............................... 3-5
Fuel tank cap ............................. 3-5
Fuel ........................................... 3-6
Fuel cock ................................... 3-7
Starter (choke) knob “ ” .......... 3-8
Steering lock ............................. 3-8
Seat ........................................... 3-9
Helmet holder ............................ 3-9
Shock absorber ....................... 3-10
Carrier ..................................... 3-10
Luggage strap holders ............ 3-10
Sidestand ................................ 3-11Ignition circuit cut-off system ... 3-11
PRE-OPERATION CHECKS ........ 4-1
Pre-operation check list ............ 4-2
OPERATION AND IMPORTANT
RIDING POINTS ........................... 5-1
Starting a cold engine ............... 5-1
Starting a warm engine ............. 5-2
Shifting ...................................... 5-2
Tips for reducing fuel
consumption ............................ 5-3
Engine break-in ......................... 5-4
Parking ...................................... 5-4
PERIODIC MAINTENANCE AND
MINOR REPAIR ............................ 6-1
Owner’s tool kit ......................... 6-1
Periodic maintenance and
lubrication chart ....................... 6-2
Removing and installing
panels ..................................... 6-5
Checking the spark plug ........... 6-6
Engine oil and oil filter
element ................................... 6-7
Cleaning the air filter element
and check hose ..................... 6-10
Adjusting the carburetor .......... 6-12Adjusting the engine idling
speed .................................... 6-12
Adjusting the throttle cable free
play ....................................... 6-13
Adjusting the valve
clearance .............................. 6-13
Tires ........................................ 6-13
Spoke wheels .......................... 6-16
Adjusting the clutch lever free
play ....................................... 6-16
Adjusting the brake lever free
play ....................................... 6-17
Adjusting the brake pedal
position and free play ............ 6-18
Adjusting the rear brake light
switch .................................... 6-19
Checking the front brake pads
and rear brake shoes ............ 6-19
Checking the brake fluid
level ....................................... 6-20
Changing the brake fluid ......... 6-21
Drive chain slack ..................... 6-21
Lubricating the drive chain ...... 6-23
Checking and lubricating the
cables .................................... 6-23
Checking and lubricating the
throttle grip and cable ........... 6-24

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SAFETY INFORMATION
1-2
1
undercornering (insufficient lean
angle for the speed).

Always obey the speed limit and
never travel faster than warrant-
ed by road and traffic conditions.

Always signal before turning or
changing lanes. Make sure that
other motorists can see you.

The posture of the operator and
passenger is important for proper
control.

The operator should keep both
hands on the handlebar and
both feet on the operator foot-
rests during operation to main-
tain control of the motorcycle.

The passenger should always
hold onto the operator, the seat
strap or grab bar, if equipped,
with both hands and keep both
feet on the passenger footrests.

Never carry a passenger unless
he or she can firmly place both
feet on the passenger footrests.

Never ride under the influence of
alcohol or other drugs.
Protective apparel
The majority of fatalities from motorcy-
cle accidents are the result of head in-
juries. The use of a safety helmet is the
single most critical factor in the preven-
tion or reduction of head injuries.

Always wear an approved helmet.

Wear a face shield or goggles.
Wind in your unprotected eyes
could contribute to an impairment
of vision that could delay seeing a
hazard.

The use of a jacket, heavy boots,
trousers, gloves, etc., is effective in
preventing or reducing abrasions
or lacerations.

Never wear loose-fitting clothes,
otherwise they could catch on the
control levers, footrests, or wheels
and cause injury or an accident.

Never touch the engine or exhaust
system during or after operation.
They become very hot and can
cause burns. Always wear protec-
tive clothing that covers your legs,
ankles, and feet.

Passengers should also observe
the precautions mentioned above.
Modifications
Modifications made to this motorcycle
not approved by Yamaha, or the re-
moval of original equipment, may ren-
der the motorcycle unsafe for use and
may cause severe personal injury.
Modifications may also make your mo-
torcycle illegal to use.
Loading and accessories
Adding accessories or cargo to your
motorcycle can adversely affect stabili-
ty and handling if the weight distribution
of the motorcycle is changed. To avoid
the possibility of an accident, use ex-
treme caution when adding cargo or
accessories to your motorcycle. Use
extra care when riding a motorcycle
that has added cargo or accessories.
Here are some general guidelines to
follow if loading cargo or adding acces-
sories to your motorcycle:
Loading
The total weight of the operator, pas-
senger, accessories and cargo must

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SAFETY INFORMATION
1-4
1
motorcycle’s electrical system an
electric failure could result, which
could cause a dangerous loss of
lights or engine power.
Gasoline and exhaust gas

GASOLINE IS HIGHLY FLAMMA-
BLE:

Always turn the engine off when
refueling.

Take care not to spill any gaso-
line on the engine or exhaust
system when refueling.

Never refuel while smoking or in
the vicinity of an open flame.

Never start the engine or let it run
for any length of time in a closed
area. The exhaust fumes are poi-
sonous and may cause loss of
consciousness and death within a
short time. Always operate your
motorcycle in an area that has ad-
equate ventilation.

Always turn the engine off before
leaving the motorcycle unattended
and remove the key from the main
switch. When parking the motorcy-cle, note the following:

The engine and exhaust system
may be hot, therefore, park the
motorcycle in a place where pe-
destrians or children are not like-
ly to touch these hot areas.

Do not park the motorcycle on a
slope or soft ground, otherwise it
may fall over.

Do not park the motorcycle near
a flammable source (e.g., a ker-
osene heater, or near an open
flame), otherwise it could catch
fire.

When transporting the motorcycle
in another vehicle, make sure that
it is kept upright and that the fuel
cock(s) are turned to “ON” or
“RES” (for vacuum type)/“OFF”
(for manual type). If the motorcycle
should lean over, gasoline may
leak out of the carburetor or fuel
tank.

If you should swallow any gaso-
line, inhale a lot of gasoline vapor,
or allow gasoline to get into youreyes, see your doctor immediate-
ly. If any gasoline spills on your
skin or clothing, immediately wash
the affected area with soap and
water and change your clothes.

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DESCRIPTION
2-2
2
3
4
5
6
7
8
9

EAU10420
Right view
1
2
65 3
4
7
1. Carrier
2. Battery (page 6-27)
3. Engine oil filter element (page 6-7)
4. Engine oil level check window (page 6-7)
5. Brake pedal (page 3-5)
6. Owner’s tool kit (page 6-1)
7. Fuse (page 6-28)

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INSTRUMENT AND CONTROL FUNCTIONS
3-1
2
34
5
6
7
8
9

EAU10450
Main switch
The main switch controls the ignition
and lighting systems. The various main
switch positions are described below.
EAU10570
ON
All electrical circuits are supplied with
power; the meter lighting, taillight and
auxiliary light come on, and the engine
can be started. The key cannot be re-
moved.
NOTE:

The headlight comes on automatically
when the engine is started and stays on
until the key is turned to “OFF”.
EAU10660
OFF
All electrical systems are off. The key
can be removed.
EAU10980
Indicator lights
EAU11020
Turn signal indicator light “”
This indicator light flashes when the
turn signal switch is pushed to the left or
right.
EAU11060
Neutral indicator light “”
This indicator light comes on when the
transmission is in the neutral position.
EAU11080
High beam indicator light “”
This indicator light comes on when the
high beam of the headlight is switched
OFFON

1. Turn signal indicator light “ ”
2. High beam indicator light “ ”
3. Neutral indicator light “ ”
3
12

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INSTRUMENT AND CONTROL FUNCTIONS
3-3
2
34
5
6
7
8
9

EAU12342
Handlebar switches
LeftRight
EAU12400
Dimmer switch “/”
Set this switch to “ ” for the high
beam and to “ ” for the low beam.
EAU12460
Turn signal switch “/”
To signal a right-hand turn, push this
switch to “ ”. To signal a left-hand
turn, push this switch to “ ”. When re-
leased, the switch returns to the center
position. To cancel the turn signal
lights, push the switch in after it has re-
turned to the center position.
EAU12500
Horn switch “”
Press this switch to sound the horn.
EAU12660
Engine stop switch “/”
Set this switch to “ ” before starting
the engine. Set this switch to “ ” to
stop the engine in case of an emergen-
cy, such as when the vehicle overturns
or when the throttle cable is stuck.
EAU12710
Start switch “”
Push this switch to crank the engine
with the starter.
CAUTION:

ECA10050
See page 5-1 for starting instruc-
tions prior to starting the engine.
1. Dimmer switch “ / ”
2. Turn signal switch “ / ”
3. Horn switch “ ”
3 1
2

1. Engine stop switch “ / ”
2. Start switch “ ”
1
2

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INSTRUMENT AND CONTROL FUNCTIONS
3-4
1
2
3
4
5
6
7
8
9

EAU12820
Clutch lever
The clutch lever is located at the left
handlebar grip. To disengage the
clutch, pull the lever toward the handle-
bar grip. To engage the clutch, release
the lever. The lever should be pulled
rapidly and released slowly for smooth
clutch operation.
The clutch lever is equipped with a
clutch switch, which is part of the igni-
tion circuit cut-off system. (See
page 3-11.)
EAU12870
Shift pedal
The shift pedal is located on the left
side of the engine and is used in com-
bination with the clutch lever when
shifting the gears of the 5-speed con-
stant-mesh transmission equipped on
this motorcycle.
EAU12890
Brake lever
The brake lever is located at the right
handlebar grip. To apply the front
brake, pull the lever toward the handle-
bar grip.
1. Clutch lever
1

1. Shift pedal1
1. Brake lever
1

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INSTRUMENT AND CONTROL FUNCTIONS
3-6
1
2
3
4
5
6
7
8
9

EAU13210
Fuel
Make sure that there is sufficient fuel in
the tank. Fill the fuel tank to the bottom
of the filler tube as shown.
WARNING

EWA10880

Do not overfill the fuel tank, oth-
erwise it may overflow when the
fuel warms up and expands.

Avoid spilling fuel on the hot en-
gine.
CAUTION:

ECA10070
Immediately wipe off spilled fuel
with a clean, dry, soft cloth, sincefuel may deteriorate painted surfac-
es or plastic parts.
EAU13320
CAUTION:

ECA11400
Use only unleaded gasoline. The use
of leaded gasoline will cause severe
damage to internal engine parts,
such as the valves and piston rings,
as well as to the exhaust system.
Your Yamaha engine has been de-
signed to use regular unleaded gaso-
line with a research octane number of
91 or higher. If knocking (or pinging) oc-
curs, use a gasoline of a different brandor premium unleaded fuel. Use of un-
leaded fuel will extend spark plug life
and reduce maintenance costs.
1. Fuel tank filler tube
2. Fuel level
1
2

Recommended fuel:
REGULAR UNLEADED GAS-
OLINE ONLY
Fuel tank capacity:
7.0 L (1.85 US gal)
(1.54 Imp.gal)
Fuel reserve amount:
1.7 L (0.45 US gal)
(0.37 Imp.gal)

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