2015 YAMAHA GRIZZLY 550 engine overheat

4-3
4
EBU30531Coolant temperature warning light “ ”
This warning light comes on when the engine
overheats. When this occurs during operation,
stop the engine as soon as it is safe to do so and
allow it to cool down for about 10 minutes.
The electrical circuit of the warning light can be
checked by turning the key to “ ” (on). The
warning light should come on for a few seconds,
and then go off.
If the warning light does not come on initially when
the key is turned to “ ” (on), or if the warning
light remains on, have a Yamaha dealer check the
electrical circuit.NOTICEECB00892The engine may overheat if the ATV is over-
loaded. In this case, reduce the load to spec-
ification.
 The engine may also overheat if mud or dirt
has accumulated on the radiator (i.e., after
riding in wet terrain). In this case, see page
8-19 for an explanation on how to access the
radiator. 
Start the engine after making sure that the
warning light is out. Continuous use while
the warning light is on may cause damage to
the engine.
EBU30481Engine trouble warning light “ ”
This warning light comes on or flashes when an
electrical circuit monitoring the engine is not work-
ing correctly. When this occurs, have a Yamaha
dealer check the self-diagnosis system. (See page
4-7 for an explanation of the self-diagnosis de-
vice.)
The electrical circuit of the warning light can be
checked by turning the key to “ ” (on). The
warning light should come on for a few seconds,
and then go off.
If the warning light does not come on initially when
the key is turned to “ ” (on), or if the warning
light remains on, have a Yamaha dealer check the
electrical circuit.
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4-4
4
EBU30571Electric Power Steering warning light “EPS”
(for EPS model)
This warning light comes on when the key is
turned to “ ” (on), and then goes off once the
engine is started. If the warning light remains on or
comes on after the engine is started, the EPS sys-
tem may not be working correctly. When this oc-
curs, have a Yamaha dealer check the EPS
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, have a Yamaha
dealer check the electrical circuit.TIPIf the engine is stopped using the engine stop
switch and the key is in the “ ” (on) position,
the EPS warning light comes on to indicate that
the power assistance for the steering is not
functioning.
 If the steering load is too heavy (i.e., excessive
steering use when the ATV is traveling at a slow
speed), the power assist is reduced to protect
the EPS motor from overheating.
EBU30451On-Command four-wheel-drive indicator “ ”,
On-Command differential gear lock
indicator “ ” and indicator light “DIFF. LOCK”
The On-Command four-wheel-drive indicator “ ”
comes on when the On-Command four-wheel-
drive switch is set to the “4WD” position.
The On-Command differential gear lock
indicator “ ” and the On-Command differential
gear lock indicator light “DIFF. LOCK” come on
when the On-Command differential gear lock
switch is set to the “LOCK” position.TIPDue to the synchronizing mechanism in the dif-
ferential gear case, the four-wheel-drive indica-
tor may not come on until the ATV starts
moving.
 When the On-Command differential gear lock
switch is set to “LOCK” or “4WD”, the
indicator “ ” and the indicator light “DIFF.
LOCK” will flash until the differential gear is
completely locked or unlocked. If the indicator
and the indicator light continue to flash, the dif-
ferential is not completely locked or unlocked.
In this case, start moving to allow time for the
differential to lock or unlock.
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6
TIPWhen in reverse, the reverse indicator light
should come on. If the indicator light does not
come on, have a Yamaha dealer check the elec-
trical circuit.
 Due to the synchronizing mechanism in the en-
gine, the indicator light may not come on until
the ATV starts moving.
4. Check behind for people or obstacles, and
then release the brake pedal.
5. Open the throttle lever gradually and continue to watch to the rear while backing.EBU20683Engine break-inTIPFor ATVs equipped with an odometer or an hour
meter, follow the figures given in km (mi) or the
figures given in hours.
 For ATVs not equipped with an odometer or
hour meter, follow the figures given in hours. There is never a more important period in the life
of your engine than the first 320 km (200 mi) or 20
hours of riding. For this reason, you should read
the following material carefully.
Since the engine is brand new, do not put an ex-
cessive load on it for the first 320 km (200 mi) or
20 hours. The various parts in the engine wear and
polish themselves to the correct operating clear-
ances. During this period, prolonged full-throttle
operation or any condition that might result in en-
gine overheating must be avoided.
1. Drive select lever
2. L (Low-range)
3. H (High-range)
4. N (Neutral)
5. R (Reverse)
6. P (Park)
L 2H 3N4R5P6
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8-32
83. If the coolant is at or below the minimum level
mark, remove panel D to access the coolant
reservoir. (See page 8-10.)
4. Remove the coolant reservoir cap, add cool- ant or distilled water to the maximum level
mark, install the reservoir cap, and then install
the panel. NOTICE: If coolant is not avail-
able, use distilled water or soft tap water
instead. Do not use hard water or salt wa-
ter since they are harmful to the engine. If
water has been used instead of coolant,
replace it with coolant as soon as possible,
otherwise 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 con-
tent of the coolant as soon as possible,
otherwise the effectiveness of the coolant
will be reduced.
[ECB01012]
TIP The radiator fan is automatically switched on or
off according to the coolant temperature in the
radiator.
 If the engine overheats, see page 8-68 for fur-
ther instructions. 1. Coolant reservoir cap
2. Maximum level mark
3. Minimum level markCoolant reservoir capacity (up to the maxi-
mum level mark):
0.24 L (0.25 US qt, 0.21 Imp.qt)
U2LB61E0.book Page 32 Friday, February 21, 2014 3:03 PM

8-41
8
6. Wash the sponge material gently, but thor-
oughly, in solvent. WARNING! Always use
parts cleaning solvent to clean the sponge
material. Never use low-flash-point sol-
vents or gasoline to clean the sponge ma-
terial because the engine could catch fire
or explode.
[EWB01942]
7. Squeeze the excess solvent out of the sponge material and let it dry. NOTICE: Do
not twist the sponge material when
squeezing it.
[ECB00442]
8. Check the sponge material and replace it if damaged.
9. Apply Yamaha foam air filter oil or other qual- ity foam air filter oil to the sponge material.
TIPThe sponge material should be wet but not drip-
ping. 10. Install the mesh and the sponge material into the air filter case. NOTICE: Make sure that
the air filter element is properly seated in
the air filter case. Never operate the en-
gine with the air filter element removed.
This will allow unfiltered air to enter the en-
gine, causing rapid engine wear and pos-
sible engine damage. Additionally,
operation without the air filter element will
affect the fuel injection system with subse-
quent poor performance and possible en-
gine overheating.
[ECB00762]
11. Insert the projections on the air filter case cover into the holders on the air filter case,
and then install the air filter case cover by
hooking the holders onto the cover.
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8-68
8Engine overheating
WARNING
EWB02291Wait for the engine and radiator to cool before removing the radiator cap. You could be burned by
hot fluid and steam blown out under pressure. Always put a thick rag over the cap when opening.
Allow any remaining pressure to escape before completely removing the cap. TIPIf 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 OK.The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer check
and repair the cooling system.Add coolant. (See TIP.)
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.
U2LB61E0.book Page 68 Friday, February 21, 2014 3:03 PM