2012 YAMAHA MT-03 engine overheat

INSTRUMENT AND CONTROL FUNCTIONS
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When the key is turned to “OFF” and
30 seconds have passed, the indicator
light will start flashing indicating the
immobilizer system is enabled. After
24 hours have passed, the indicator
light will stop flashing, however the im-
mobilizer system is still enabled.
This model is also equipped with a
self-diagnosis device for the immobi-
lizer system. (See page 3-7 for an ex-
planation of the self-diagnosis device.)
EAU11060
Neutral indicator light “N”
This indicator light comes on when the
transmission is in the neutral position.
EAU11020
Turn signal indicator light “y”
This indicator light flashes when the
turn signal switch is pushed to the left
or right.
EAU11080
High beam indicator light “1”
This indicator light comes on when the
high beam of the headlight is switched
on.
EWA10060
WARNING0
Never turn the key to “OFF” or
“LOCK” while the vehicle is moving,
otherwise the electrical systems
will be switched off, which may re-
sult in loss of control or an acci-
dent. Make sure that the vehicle is
stopped before turning the key to
“OFF” or “LOCK”.
EAU11530
Engine trouble warning light “U”
This warning light comes on or flashes
when an electrical circuit monitoring
the engine is defective. When this oc-
curs, have a Yamaha dealer check the
self-diagnosis system. (See page 3-7
for an explanation of the self-diagno-
sis device.)
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.
EAU11440
Coolant temperature warning
light “u”
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.
EAU11361
Fuel level warning light “K”
This warning light comes on when the
fuel level drops below approximately
4.25 L (1.12 US gal) (0.93 Imp.gal).
When this occurs, refuel as soon as
possible.

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OPERATION AND IMPORTANT RIDING POINTS
ECA10260CAUTION:
●Even with the transmission in
the neutral position, do not
coast for long periods of time
with the engine off, and do not
tow the motorcycle for long
distances. The transmission is
properly lubricated only when
the engine is running. Inade-
quate lubrication may damage
the transmission.
●Always use the clutch while
changing gears to avoid dam-
aging the engine, transmission,
and drive train, which are not
designed to withstand the
shock of forced shifting.
EAU16810
Tips for reducing fuel
consumption
Fuel consumption depends largely on
your riding style. Consider the follow-
ing tips to reduce fuel consumption:
●Shift up swiftly, and avoid high en-
gine speeds during acceleration.
●Do not rev the engine while shift-
ing down, and avoid high engine
speeds with no load on the en-
gine.
●Turn the engine off instead of let-
ting it idle for an extended length
of time (e.g., in traffic jams, at traf-
fic lights or at railroad crossings).
EAU16841
Engine break-in
There is never a more important peri-
od in the life of your engine than the
period between 0 and 1600 km (1000
mi). For this reason, you should read
the following material carefully.
Since the engine is brand new, do not
put an excessive load on it for the first
1600 km (1000 mi). The various parts
in the engine wear and polish them-
selves to the correct operating clear-
ances. During this period, prolonged
full-throttle operation or any condition
that might result in engine overheating
must be avoided.
5-3

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PERIODIC MAINTENANCE AND MINOR REPAIR
EWA10380
WARNING0
Never attempt to remove the radia-
tor cap when the engine is hot.
NOTE:
●The radiator fan is automatically
switched on or off according to
the coolant temperature in the ra-
diator.
●If the engine overheats, see page
3-4 for further instructions.
EAU33030
Changing the coolant
EWA10380
WARNING0
Never attempt to remove the radia-
tor cap when the engine is hot.
The coolant must be changed at the
intervals specified in the periodic
maintenance and lubrication chart.
Have a Yamaha dealer change the
coolant.
EAUB1280
Replacing the air filter
element and cleaning the
check hoses
The air filter element should be re-
placed at the intervals specified in the
periodic maintenance and lubrication
chart. Replace the air filter element
more frequently if you are riding in un-
usually wet or dusty areas. In addition,
the air filter check hoses must be fre-
quently checked and cleaned if neces-
sary. To replace the air filter element
1. Air filter case
2. Screws
1. Remove the air filter case cover
by removing the screws.
2. Pull the air filter element out.
3. Insert a new air filter element into
the air filter case as shown.
6-13

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PERIODIC MAINTENANCE AND MINOR REPAIR
6-41
Engine overheatingEWA10400
WARNING0
●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 hiss-
ing sound has stopped, press down on the cap while turning it counterclockwise, and then remove the cap.
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.
Wait until the
engine has cooled.Check the coolant level
in the reservoir and radiator.
The coolant level is low.
Check the cooling
system for leakage.
The coolant level
is OK.
There is
leakage.
There is no
leakage.
Have a Yamaha dealer check
and repair the cooling system.
Start the engine. If the engine overheats again, have
a Yamaha dealer check and repair the cooling system.
Add coolant. (See NOTE.)

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INDEX
Throttle grip and cable, checking
and lubricating ..............................6-25
Tips for reducing fuel consumption ....5-3
Tires .................................................6-16
Air pressure ..................................6-16
Tire information .............................6-18
Tire inspection ..............................6-17
Tool kit ................................................6-1
Troubleshooting................................6-39
Troubleshooting charts .................6-40
Engine overheating .......................6-41
Turn signal indicator light ...................3-4
Turn signal light bulb, replacing .......6-35
Turn signal switch..............................3-9
V
Valve clearance ................................6-15
Vehicle identification number .............9-1
W
Warning lights ....................................3-4
Wheel bearings, checking ................6-29
Wheels, cast.....................................6-19