2002 YAMAHA TW125 engine

EAU00009
TABLE OF CONTENTS
GIVE SAFETY THE RIGHT OF WAY ............... 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 ........................................ 3-2
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 ................................. 4-1
OPERATION AND IMPORTANT RIDING
POINTS ............................................................. 5-1
Starting the engine ......................................... 5-1
Starting a warm engine .................................. 5-2
Shifting ........................................................... 5-3
Recommended shift points
(for Switzerland only) .................................. 5-3
Tips for reducing fuel consumption ................ 5-4
Engine break-in .............................................. 5-4
Parking ........................................................... 5-5
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 ................................ 6-7
Engine oil and oil filter element ...................... 6-9
Cleaning the air filter element and check
hose .......................................................... 6-12
Adjusting the carburetor ............................... 6-14
Adjusting the engine idling speed ................ 6-14
123
456
5RS-9-E0 (TW125) 7/30/01 6:02 PM Page 5

2-2
DESCRIPTION
2
Right view10. Carrier (page 3-10)
11. Battery (page 6-32)
12. Engine oil filter element (page 6-9)
13. Engine oil level check window (page 6-9)
14. Brake pedal (page 3-5, 6-21)15. Owner’s tool kit (page 6-1)
16. Fuse (page 6-33)
10
11
15 14 12
13
16
5RS-9-E0 (TW125) 7/30/01 6:02 PM Page 9

3-1
EAU00027
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU00028
Main switchMain switchThe main switch controls the ignition
and lighting systems. The various
main switch positions are described
below.
EAU00036
ON
All electrical systems are supplied
with power, and the engine can be
started. The key cannot be removed.
EAU00038
OFF
All electrical systems are off. The key
can be removed.
EAU00061
Neutral indicator light “N”
This indicator light comes on when
the transmission is in the neutral
position.
OFFON
EAU00056
Indicator lights
EAU00057
Turn signal indicator light “
5”
This indicator light flashes when the
turn signal switch is pushed to the left
or right.
EAU00063
High beam indicator light “&”
This indicator light comes on when
the high beam of the headlight is
switched on.
3
12
1. Turn signal indicator light “5”
2. High beam indicator light “&”
3. Neutral indicator light “N”
5RS-9-E0 (TW125) 7/30/01 6:02 PM Page 11

3-3
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU03888
Dimmer switch “&/%”
Set this switch to “&” for the high
beam and to “%” for the low beam.
EAU03889
Turn signal switch “4/6”
To signal a right-hand turn, push this
switch to “6”. To signal a left-hand
turn, push this switch to “4”. When
released, the switch returns to the
center position. To cancel the turn
signal lights, push the switch in after
it has returned to the center position.
EAU00129
Horn switch “*”
Press this switch to sound the horn.
EAU00143
Start switch “,”
Push this switch to crank the engine
with the starter.
EC000005
cCSee page 5-1 for starting instruc-
tions prior to starting the engine.
EAU03890
Engine stop switch “#/$”
Set this switch to “#” before starting
the engine. Set this switch to “$” to
stop the engine in case of an emer-
gency, such as when the motorcycle
overturns or when the throttle cable is
stuck.
1
2
1. Engine stop switch “#/$”
2. Start switch “,”
5RS-9-E0 (TW125) 7/30/01 6:03 PM Page 13

3-4
EAU00152
Clutch leverThe clutch lever is located at the left
handlebar grip. To disengage the
clutch, pull the lever toward the han-
dlebar 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 for an explanation of the ignition
circuit cut-off system.)INSTRUMENT AND CONTROL FUNCTIONS
3
1
1. Clutch lever
EAU00158
Brake leverThe brake lever is located at the right
handlebar grip. To apply the front
brake, pull the lever toward the han-
dlebar grip.
1
1. Brake lever
EAU00157
Shift pedalThe shift pedal is located on the left
side of the engine and is used in
combination with the clutch lever
when shifting the gears of the
5-speed constant-mesh transmission
equipped on this motorcycle.
1
1. Shift pedal
5RS-9-E0 (TW125) 7/30/01 6:03 PM Page 14

3-6
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU03753
FuelMake sure that there is sufficient fuel
in the tank. Fill the fuel tank to the
bottom of the filler tube as shown.
EW000130
w8Do not overfill the fuel tank,
otherwise it may overflow
when the fuel warms up and
expands.
8Avoid spilling fuel on the hot
engine.
1
2
1. Filler tube
2. Fuel level
ECA00104
cCUse only unleaded gasoline. The
use of leaded gasoline will cause
severe damage to internal engine
parts, such as the valves and pis-
ton rings, as well as to the exhaust
system.Your Yamaha engine has been
designed to use regular unleaded
gasoline with a research octane num-
ber of 91 or higher. If knocking (or
pinging) occurs, use a gasoline of a
different brand or premium unleaded
fuel. Use of unleaded fuel will extend
spark plug life and reduce mainte-
nance costs.
EAU00185
cCImmediately wipe off spilled fuel
with a clean, dry, soft cloth, since
fuel may deteriorate painted sur-
faces or plastic parts.
EAU04284
Recommended fuel:
REGULAR UNLEADED
GASOLINE ONLY
Fuel tank capacity:
Total amount:
7.0 L
Reserve amount:
1.0 L
5RS-9-E0 (TW125) 7/30/01 6:03 PM Page 16

3-7
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU03050
Fuel cockThe fuel cock supplies fuel from the
tank to the carburetor while filtering it
also.
The fuel cock has three positions:
OFF
With the lever in this position, fuel will
not flow. Always return the lever to
this position when the engine is not
running.
RES
ONFUEL
OFF
1
1. Arrow mark positioned over “OFF”
RES
This indicates reserve. If you run out
of fuel while riding, move the lever to
this position. Fill the tank at the first
opportunity. Be sure to set the lever
back to “ON” after refueling!
OFF
ONFUEL RES
1
RES
1. Arrow mark positioned over “RES”
ON
With the lever in this position, fuel
flows to the carburetor. Normal riding
is done with the lever in this position.
ON
FUEL
RES
OFF
1
ON
1. Arrow mark positioned over “ON”
OFF: Closed position
ON: Normal position
RES: Reserve position
5RS-9-E0 (TW125) 7/30/01 6:03 PM Page 17

3-8
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU04038
Starter (choke) knob“1”Starting a cold engine requires a rich-
er air-fuel mixture, which is supplied
by the starter (choke).
Move the knob in direction ato turn
on the starter (choke).
Move the knob in direction bto turn
off the starter (choke).
a
b
1
1. Starter (choke) knob “1”
4. Check that the steering is locked,
remove the key, and then close
the lock cover.
To unlock the steering
1. Open the steering lock cover,
and then insert the steering lock
key.
2. Push the key in, turn it 1/8 turn
counterclockwise so that it
moves out, and then release it.
3. Remove the key, and then close
the lock cover.
EAU03342
Steering lockSteering lockTo lock the steering
1. Turn the handlebar all the way to
right.
2. Open the steering lock cover,
and then insert the steering lock
key.
3. Turn the key 1/8 turn counter-
clockwise, push it in while turning
the handlebar slightly to the left,
and then turn the key 1/8 turn
clockwise.
21
1. Steering lock cover
2. Steering lock
5RS-9-E0 (TW125) 7/30/01 6:03 PM Page 18