2008 YAMAHA YZF-R125 engine overheat

INSTRUMENT AND CONTROL FUNCTIONS
3-2
3
EAU11003
Indicator and warning 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
on.
EAUM2290
Coolant temperature warning
light“”
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 cir-
cuit.CAUTION:
ECA10020
Do not operate the engine if it isoverheated.
EAU11500
Engine trouble warning light“”
This warning light comes on or flashes
when an electrical circuit monitoring the
engine is defective. When this occurs,
have a Yamaha dealer check the self-
diagnosis system.
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.
1. Neutral indicator light“”
2. Turn signal indicator light“”
3. High beam indicator light“”
4. Engine trouble warning light“”
5. Coolant temperature warning light“”U5D7E0E0.book Page 2 Tuesday, December 18, 2007 10:13 AM

OPERATION AND IMPORTANT RIDING POINTS
5-3
5
EAU16810
Tips for reducing fuel con-
sumption Fuel consumption depends largely on
your riding style. Consider the following
tips to reduce fuel consumption:

Shift up swiftly, and avoid high en-
gine speeds during acceleration.


Do not rev the engine while shifting
down, and avoid high engine
speeds with no load on the engine.


Turn the engine off instead of let-
ting it idle for an extended length of
time (e.g., in traffic jams, at traffic
lights or at railroad crossings).
EAU16830
Engine break-in There is never a more important period
in the life of your engine than the period
between 0 and 1000 km (600 mi). For
this reason, you should read the follow-
ing material carefully.
Since the engine is brand new, do not
put an excessive load on it for the first
1000 km (600 mi). The various parts in
the engine wear and polish themselves
to the correct operating clearances.
During this period, prolonged full-throt-
tle operation or any condition that might
result in engine overheating must be
avoided.
EAU16980
0–500 km (0–300 mi)
Avoid prolonged operation above 6000
r/min.
After every hour of operation, stop the
engine, and then let it cool for five to ten
minutes.
Vary the engine speed from time to
time. Do not operate the engine at one
set throttle position.500–1000 km (300–600 mi)
Avoid prolonged operation above 8000
r/min.
Rev the engine freely through the
gears, but do not use full throttle at any
time.
CAUTION:
ECA10320
After 1000 km (600 mi) of operation,
the engine oil must be changed, the
oil filter cartridge or element re-placed, and the oil strainer cleaned.
1000 km (600 mi) and beyond
The vehicle can now be operated nor-
mally.CAUTION:
ECA10310


Keep the engine speed out of
the tachometer red zone.


If any engine trouble should oc-
cur during the engine break-in
period, immediately have a
Yamaha dealer check the vehi-cle.
U5D7E0E0.book Page 3 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-13
6 3. If the coolant is at or below the
minimum level mark, remove the
reservoir cap.4. Add coolant to the maximum level
mark, and then install the reservoir
cap.
CAUTION:
ECA10471


If coolant is not available, use
distilled water or soft tap water
instead. Do not use hard water
or salt water since it is harmful
to the engine.


If water has been used instead
of coolant, replace it with cool-
ant as soon as possible, other-
wise the cooling system will not
be protected against frost and
corrosion.


If water has been added to the
coolant, have a Yamaha dealer
check the antifreeze content of
the coolant as soon as possible,
otherwise the effectiveness ofthe coolant will be reduced.
WARNING
EWA10380
Never attempt to remove the radiatorcap when the engine is hot.NOTE:

The radiator fan is automatically
switched on or off according to the
coolant temperature in the radia-
tor.


If the engine overheats, see page6-37 for further instructions.
EAU33030
Changing the coolant
WARNING
EWA10380
Never attempt to remove the radiatorcap when the engine is hot.
The coolant must be changed at the in-
tervals specified in the periodic mainte-
nance and lubrication chart. Have a
Yamaha dealer change the coolant.
1. Coolant reservoir
2. Maximum level mark
3. Minimum level mark
1. Coolant reservoir cap
Coolant reservoir capacity (up to the
maximum level mark):
0.25 L (0.26 US qt) (0.22 Imp.qt)
U5D7E0E0.book Page 13 Tuesday, December 18, 2007 10:13 AM

PERIODIC MAINTENANCE AND MINOR REPAIR
6-38
6Engine overheating
WARNING
EWA10400


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 hissingsound 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 coolantas soon as possible.
Wait 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.
U5D7E0E0.book Page 38 Tuesday, December 18, 2007 10:13 AM