engine YAMAHA TW125 2003 Owners Manual

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 .........................................3-3
Clutch lever .....................................................3-4
Shift pedal .......................................................3-4
Brake lever ......................................................3-5
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 ................................................3-10
Shock absorber .............................................3-10
Carrier ...........................................................3-10
Luggage strap holders ..................................3-11
Sidestand ......................................................3-11Ignition circuit cut-off system .........................3-12
PRE-OPERATION CHECKS .............................4-1
Pre-operation check list ...................................4-1
OPERATION AND IMPORTANT RIDING
POINTS ..............................................................5-1
Starting a cold 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 .................6-141
2
3
4
5
6
5RS-9-E1 (TW125) 8/23/02 11:37 AM Page 5

2-2
DESCRIPTION
2
10. 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
1316
Right view
5RS-9-E1 (TW125) 8/23/02 11:37 AM Page 9

3-1
EAU00027
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU00028
Main switch
The main switch controls the ignition
and lighting systems. The various
main switch positions are described
below.
EAU04926
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 can-
not be removed.
OFFON
EAU00056
Indicator lightsEAU00057
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.
312
1. Turn signal indicator light “5”
2. High beam indicator light “&”
3. Neutral indicator light “N”
NOTE:
The headlight comes on automatical-
ly when the engine is started and
stays on until the key is turned to
“OFF”.
EAU00038
OFF
All electrical systems are off. The key
can be removed.
5RS-9-E1 (TW125) 8/23/02 11:37 AM Page 11

3-3
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU00118
Handlebar switchesEAU03888
Dimmer switch “&/%”
Set this switch to “&” for the high
beam and to “%” for the low beam.
3 1
2
1. Dimmer switch “&/%”
2. Turn signal switch “4/6”
3. Horn switch “*”
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.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-E1 (TW125) 8/23/02 11:37 AM Page 13

3-4
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU00152
Clutch lever
The 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
3-12 for an explanation of the ignition
circuit cut-off system.)
1
1. Clutch lever
EAU00157
Shift pedal
The 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
EAU00143
Start switch “,”
Push this switch to crank the engine
with the starter.
EC000005
cC
See page 5-1 for starting instruc-
tions prior to starting the engine.
1
2
1. Engine stop switch “#/$”
2. Start switch “,”
5RS-9-E1 (TW125) 8/23/02 11:37 AM Page 14

3-6
To install the fuel tank cap
1. Insert the fuel tank cap into the
tank opening with the key insert-
ed in the lock, and then turn the
cap 1/3 turn clockwise.
2. Turn the key 1/3 turn clockwise,
and then remove it.
NOTE:
The fuel tank cap cannot be installed
unless the key is in the lock. In addi-
tion, the key cannot be removed if the
cap is not properly installed and
locked.
EW000023
w
Make sure that the fuel tank cap is
properly closed and locked before
riding.
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU03753
Fuel
Make sure that there is sufficient fuel
in the tank. Fill the fuel tank to the
bottom of the filler tube as shown.
EW000130
w
8Do 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
EAU00185
cC
Immediately 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:
1.7 L
5RS-9-E1 (TW125) 8/23/02 11:37 AM Page 16

3-7
INSTRUMENT AND CONTROL FUNCTIONS
3
ECA00104
cC
Use 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.EAU03050
Fuel cock
The 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”
ON
With the lever in this position, fuel
flows to the carburetor. Normal riding
is done with the lever in this position.
ONFUEL
RES
OFF
1ON
1. Arrow mark positioned over “ON”
OFF: Closed positionON: Normal position
5RS-9-E1 (TW125) 8/23/02 11:37 AM Page 17

3-8
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!
INSTRUMENT AND CONTROL FUNCTIONS
3
OFF
ONFUEL RES
1
RES
1. Arrow mark positioned over “RES”
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”
EAU03342
Steering lock
To lock the steering
1. Turn the handlebar all the way to
the 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
RES: Reserve position
5RS-9-E1 (TW125) 8/23/02 11:37 AM Page 18

3-12
EAU03720
Ignition circuit cut-off
system
The ignition circuit cut-off system
(comprising the sidestand switch,
clutch switch and neutral switch) has
the following functions.
8It prevents starting when the
transmission is in gear and the
sidestand is up, but the clutch
lever is not pulled.
8It prevents starting when the
transmission is in gear and the
clutch lever is pulled, but the
sidestand is still down.
8It cuts the running engine when
the transmission is in gear and
the sidestand is moved down.
Periodically check the operation of
the ignition circuit cut-off system
according to the following procedure.
EW000045
w
If a malfunction is noted, have a
Yamaha dealer check the system
before riding.
INSTRUMENT AND CONTROL FUNCTIONS
3
5RS-9-E1 (TW125) 8/23/02 11:37 AM Page 22

3-13
INSTRUMENT AND CONTROL FUNCTIONS
3
With the engine turned off:
1. Move the sidestand down.
2. Make sure that the engine stop switch is set to “
#”.
3. Turn the key to “ON”.
4. Shift the transmission into the neutral position.
5. Push the start switch.
Does the engine start?
The neutral switch may be defective.
The motorcycle should not be ridden until
checked by a Yamaha dealer.
With the engine still running:
6. Move the sidestand up.
7. Keep the clutch lever pulled.
8. Shift the transmission into gear.
9. Move the sidestand down.
Does the engine stall?
After the engine has stalled:
10. Move the sidestand up.
11. Keep the clutch lever pulled.
12. Push the start switch.
Does the engine start?
The sidestand switch may be defective.
The motorcycle should not be ridden until
checked by a Yamaha dealer.
The clutch switch may be defective.
The motorcycle should not be ridden until
checked by a Yamaha dealer.
NO
NOTE:
This check is most reliable if performed with
a warmed-up engine.
YES
YES NO
The system is OK. The motorcycle can be ridden.
YES NO
5RS-9-E1 (TW125) 8/23/02 11:37 AM Page 23