2003 YAMAHA TZR50 engine overheat

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/steering lock .................3-1
Indicator lights ..................................3-1
Speedometer unit .............................3-2
Tachometer .......................................3-3
Handlebar switches ..........................3-3
Clucht lever .......................................3-4
Shift pedal.........................................3-4
Brake lever ........................................3-4
Brake pedal.......................................3-5
Fuel tank cap ....................................3-5
Catalytic converter............................3-6
2-stroke engine oil ............................3-6
Fuel cock ..........................................3-6
Starter (choke) lever..........................3-7
Seat...................................................3-7
Storage compartment.......................3-7
Sidestand ..........................................3-8
Ignition circuit cut-off system ...........3-8
PRE-OPERATION CHECKS...............4-1
Pre-operation check list....................4-2OPERATION AND IMPORTANT RIDING
POINTS................................................5-1
Starting a cold engine ......................5-1
Shifting ..............................................5-2
Tips for reducing fuel consumption..5-2
Engine break-in.................................5-3
Parking ..............................................5-3
PERIODIC MAINTENANCE AND
MINOR RAPAIR...................................6-1
Owner’s tool kit .................................6-1
Periodic maintenance and lubrication
chart ..................................................6-2
Removing and installing cowlings ....6-5
Checking the spark plug ..................6-6
Transmission oil ................................6-6
To check the coolant level ................6-8
Adjusting the carburetor ...................6-9
Adjusting the engine idling speed ....6-9
Adjusting the throttle cable free play ..6-9
Tires ................................................6-10
Cast wheels ....................................6-12
Adjusting the clucth lever free play 6-12
Adjusting the brake pedal position
and free play................................6-13
Adjusting the rear brake light
switch ..........................................6-13
Front brake pads ............................6-14
Rear brake pads .............................6-14
Checking the brake fluid level ........6-14
Changing the brake fluid ................6-15Drive Chain slack ............................6-16
Checking and lubricating the
cables ..........................................6-17
Checking and lubricating the brake
and shift pedals ...........................6-17
Checking and lubricating the brake
and cluctch levers .......................6-18
Checking and lubricating the
sidestand .....................................6-18
Checking the front fork ...................6-18
Checking the steering.....................6-19
Checking the wheel bearings .........6-19
Battery ............................................6-19
Replacing the fuse ..........................6-20
Replacing the headlight bulb..........6-21
Replacing a turn signal light bulb
or the tail/brake light bulb ...........6-21
Replacing the license plate light
bulb .............................................6-22
Supporting the mortorcycle ............6-22
Troubleshooting ..............................6-23
Troubleshooting charts ...................6-24
Engine overheating .........................6-25
MOTORCYCLE CARE AND
STORAGE............................................7-1
Care ..................................................7-1
Storage ...........................................7-2
SPECIFITACIONS...............................8-1
TABLE OF CONTENTS
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EAU11020
Turn signal indicator light “b”
This indicator light flashes when the
turn signal switch is pushed to the left
or right.
EAU11060
Neutral indicator light “N”
This indicator light comes on when
the transmission is in the neutral posi-
tion.
EAU11120
Oil level warning light “z”
This warning light comes on when the
engine oil level is low.
The electrical circuit of the warning
light can be checked by turning the
key to “ON”.
If the warning light does not come on
for a few seconds, then go off, have a
Yamaha dealer check the electrical
circuit.
NOTE:
Even if the oil level is sufficient, the
warning light may flicker when riding
on a slope or during sudden accelera-
tion or deceleration, but this is not a
malfunction.
EAU11440
Coolant temperature warning light
“y”
This warning light comes on when the
engine overheats. When this occurs,
stop the engine immediately and
allow the engine to cool.
The electrical circuit of the warning
light can be checked by turning the
key to “ON”.
If the warning light does not come on
for a few seconds, then go off, have a
Yamaha dealer check the electrical
circuit.
ECA10020
CAUTION
Do not operate the engine if it is
overheated.
EAU11620
Speedometer unit
1. Speedometer/Odometer
The speedometer unit is equipped
with a speedometer and an odometer.
The speedometer shows riding spe-
ed. The odometer shows the total dis-
tance traveled.
3
INSTRUMENT AND CONTROL FUNCTIONS
3-2
1
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NOTE:
If the engine overheats, see page 6-5
for further instructions.
EAU21300
Adjusting the carburetor
The carburetor is an important part of
the engine and requires very sophisti-
cated adjustment. Therefore, all car-
buretor adjustments should be left to
a Yamaha dealer, who has the neces-
sary professional knowledge and
experience.
EAU21320
Adjusting the engine idling
speed
1. Idle aedjusting bolt
The engine idling speed must be
checked and, if necessary, adjusted
as follows at the intervals specified in
the periodic maintenance and lubrica-
tion chart.
The engine should be warm before
making this adjustment.
NOTE:
The engine is warm when it quickly
responds to the throttle.
Check the engine idling speed and, if
necessary, adjust it to specification by
turning the throttle stop screw. To
increase the engine idling speed, turn
the screw in direction (a). To decrease
the engine idling speed, turn the
screw in direction (b).
NOTE:
If the specified idling speed cannot be
obtained as described above, have a
Yamaha dealer make the adjustment.
EAU21370
Adjusting the throttle cable
free play
(a) Throttle cable free play
The throttle cable free play should
measure 2~5 mm (0,08~0,2 in) at the
throttle grip. Periodically check the
throttle cable free play and, if neces-
sary, adjust it as follows.
NOTE:
The engine idling speed must be
correctly adjusted before checking
and adjusting the throttle cable free
play.
Engine idling speed:
1700 ~ 2000 tpm
6
PERIODIC MAINTENANCE AND MINOR REPAIR
1a
6-9
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Engine overheatingEWA10400
s s
WARNING
Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be
blown out under pressure, which could cause serious injury. Be sure to wait until the engine has cooled.
After removing the radiator cap retaining bolt, place a thick rag, like a towel, over the radiator cap, and then
slowly rotate the cap counterclockwise to the detent to allow any residual pressure to escape. When the his-
sing sound has stopped, press down on the cap while turning it counterclockwise, and then remove the cap.
PERIODIC MAINTENANCE AND MINOR REPAIR
6-25
6Wait until the
engine has cooled.Check the coolant level in the
reservoir and radiator.
The coolant level
is OK.
The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer checkand repair the cooling system.
Add coolant. (See NOTE.)
Start the engine. If the engine overheats again, have a
Yamaha dealer check and repair the cooling system.
There is
leakage.
There is
no leakage.
NOTE:
If coolant is not available, tap water can be temporarily used instead, provided that it is changed to the recommended
coolant as soon as possible.
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AAdjusting the brake pedal position and
free play .................................................6-13
Adjusting the carburetor ............................6-9
Adjusting the clucth lever free play .........6-12
Adjusting the engine idling speed .............6-9
Adjusting the rear brake light switch .......6-13
Adjusting the throttle cable free play .........6-9
BBattery......................................................6-19
Brake lever .................................................3-4
Brake pedal ................................................3-5
CCare............................................................7-1
Cast wheels .............................................6-12
Catalytic converter .....................................3-6
Clucht lever ................................................3-4
Controls and instruments ..........................2-3
Changing the brake fluid..........................6-15
Checking and lubricating the brake and
cluctch levers.........................................6-18
Checking and lubricating the brake
and shift pedals .....................................6-17
Checking and lubricating the cables .......6-17
Checking and lubricating the sidestand ..6-18
Checking the brake fluid level .................6-14
Checking the front fork ............................6-18
Checking the spark plug ............................6-6
Checking the steering ..............................6-19
Checking the wheel bearings ..................6-19
D2-stroke engine oil ........................................3-6
Drive Chain slack........................................6-16
EEngine break-in ..........................................5-3
Engine overheating ..................................6-25
FFrame serial number ..................................9-1
Front brake pads......................................6-14
Fuel cock....................................................3-6
Fuel tank cap .............................................3-5
HHandlebar switches ...................................3-3
IIdentification numbers ...............................9-1
Ignition circuit cut-off system ....................3-8
Indicator lights ...........................................3-1
KKey identification number ..........................9-1
LLeft view .....................................................2-1
MMain switch/steering lock ..........................3-1
Model label ................................................9-2
OOwner’s tool kit ..........................................6-1
PParking .......................................................5-3
Periodic maintenance and lubrication
chart .........................................................6-2
Pre-operation check list .............................4-2
RRear brake pads ......................................6-14
Removing and installing cowlings .............6-5
Replacing a turn signal light bulb or the
tail/brake light bulb ................................6-21Replacing the fuse ...................................6-20
Replacing the headlight bulb ...................6-21
Replacing the license plate light bulb......6-22
Right view ..................................................2-2
SSeat ............................................................3-7
Shift pedal ..................................................3-4
Shifting .......................................................5-2
Sidestand ...................................................3-8
Speedometer unit ......................................3-2
Starter (choke) lever ...................................3-7
Starting a cold engine ................................5-1
Storage.......................................................7-2
Storage compartment ................................3-7
Supporting the mortorcycle .....................6-22
TTachometer ................................................3-3
Tips for reducing fuel consumption ...........5-2
Tires .........................................................6-10
To check the coolant level .........................6-8
Transmission oil .........................................6-6
Troubleshooting .......................................6-23
Troubleshooting charts ............................6-24
INDEX
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