2015 YAMAHA GRIZZLY 450 engine

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8
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 8-65 for fur-
ther instructions. EBU23606To change the coolant
WARNING
EWB01891Wait 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 place a thick rag over the cap
when opening. Allow any remaining pressure
to escape before completely removing the cap. 1. Place the ATV on a level surface.
2. Remove panels D and E. (See page 8-10.)
3. Place a container under the engine, and then
remove the coolant drain bolt and its gasket.
(Use a trough or a similar object as shown to
prevent coolant from spilling on the footrest.)
1. Coolant reservoir capCoolant reservoir capacity (up to the maxi-
mum level mark):0.25 L (0.26 US qt, 0.22 Imp.qt)
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8
9. After draining the coolant, thoroughly flush
the cooling system with clean tap water.
10. Install the coolant drain bolt and its new gas- ket, and then tighten the bolt to the specified
torque.
11. Connect the coolant reservoir hose.
12. Pour the recommended coolant into the res- ervoir to the maximum level mark, and then
install the reservoir cap. NOTICE: Mix anti- freeze with distilled water only. However, if
distilled water is not available, soft water
may be used for refilling. Do not use hard
water or salt water since they are harmful
to the engine.
[ECB00992]
13. Pour the recommended coolant into the radi-
ator until it is full.
14. Install the radiator cap, start the engine, let it idle for several minutes, and then turn it off.
15. Remove the radiator cap to check the coolant level in the radiator. If it is low, add sufficient
coolant until it reaches the top of the radiator,
and then install the radiator cap.
1. Coolant reservoir hoseTightening torque:Coolant drain bolt:10 Nm (1.0 m·kgf, 7.2 ft·lbf)
1
Antifreeze/water mixture ratio: 1:1
Recommended antifreeze: High-quality ethylene glycol antifreeze con-
taining corrosion inhibitors for aluminum
engines
Coolant quantity: Radiator capacity (including all routes):1.32 L (1.40 US qt, 1.16 Imp.qt)
Coolant reservoir capacity (up to the maxi-
mum level mark): 0.25 L (0.26 US qt, 0.22 Imp.qt)
U2LC61E0.book Page 29 Wednesday, February 26, 2014 3:56 PM

8-30
816. Start the engine, and then check for coolant
leakage.
TIPIf any leakage is found, have a Yamaha dealer
check the cooling system. 17. Install the panels and the front carrier.EBU23647Cleaning the air filter elementThe air filter element should be cleaned at the in-
tervals specified in the periodic maintenance and
lubrication chart. Clean or, if necessary, replace
the air filter element more frequently if you are rid-
ing in unusually wet or dusty areas.TIPThere is a check hose at the bottom of the air filter
case. If dust or water collects in this hose, empty
the hose and clean the air filter element and air fil-
ter case.
1. Place the ATV on a level surface.
2. Remove the seat. (See page 4-19.)
3. Remove the air filter case cover by unhookingthe air filter case cover holders.1. Air filter case check hose
U2LC61E0.book Page 30 Wednesday, February 26, 2014 3:56 PM

8-32
86. 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. Pull the sponge material over the air filter ele- ment frame, and then install the lock plate.
11. Insert the air filter element into the air filter case, and then install the air filter case cover
by hooking the holders onto the air filter case.
NOTICE: Make sure that the air filter ele-
ment is properly seated in the air filter
1. Air filter element frame
2. Sponge material
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8
case. Never operate the engine with the air
filter element removed. This will allow un-
filtered air to enter the engine, causing
rapid engine wear and possible engine
damage. Additionally, operation without
the air filter element will affect carburetor
jetting with subsequent poor performance
and possible engine overheating.
[ECB00462]
12. Install the seat.TIPThe air filter element should be cleaned every 20–
40 hours. It should be cleaned and lubricated
more often if the ATV is operated in extremely
dusty areas. Each time the air filter element main-
tenance is performed, check the air inlet of the air
filter case for obstructions. Check the air filter
case rubber joint to the carburetor fittings and the
rubber joint manifold fittings for an air-tight seal.
Tighten all fittings securely to avoid the possibility
of unfiltered air entering the engine. EBU27083Cleaning the spark arresterBe sure the exhaust pipe and muffler are cool be-
fore cleaning the spark arrester.
1. Remove the tailpipe bolts. 2. Remove the tailpipe by pulling it out of the
muffler.
3. Tap the tailpipe lightly, and then use a wire brush to remove any carbon deposits from
the spark arrester portion of the tailpipe and
inside of the tailpipe housing.
1. Tailpipe bolt
2. Tailpipe
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84. Insert the tailpipe into the muffler and align
the bolt holes.
5. Install the tailpipe bolts and tighten them to the specified torque.
WARNING
EWB02341Do not start the engine when cleaning the
spark arrester, otherwise it could cause injury
to the eyes, burns, carbon monoxide poison-
ing, possibly leading to death, and start a fire.
Always let the exhaust system cool prior to
touching exhaust components. EBU23921V-belt cooling duct check hoseIf dust or water collects in the V-belt cooling duct
check hose, remove the hose and clean it.
1. Tailpipe
2. Spark arresterTightening torque:Tailpipe bolt:10 Nm (1.0 m·kgf, 7.2 ft·lbf)
1. V-belt cooling duct check hose (left front side of ATV)
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8
EBU23932V-belt case drain plugAfter riding in water deep enough to allow it to en-
ter the V-belt case, remove the V-belt case drain
plug to drain the water from the case.TIPIf water drains from the V-belt case after removing
the plug, have a Yamaha dealer check the ATV as
the water may affect other engine parts.
EBU23941Adjusting the carburetorThe carburetor should be checked and, if neces-
sary, adjusted at the intervals specified in the pe-
riodic maintenance and lubrication chart. The
carburetor is an important part of the engine and
requires very sophisticated adjustment. There-
fore, most carburetor adjustments should be left
to a Yamaha dealer, who has the necessary pro-
fessional knowledge and experience. The adjust-
ment described in the following section, however,
may be performed by the owner as part of routine
maintenance.NOTICEECB00481The carburetor has been set and extensively
tested at the Yamaha factory. Changing these
settings without sufficient technical knowl-
edge may result in poor performance of or
damage to the engine. EBU24011Adjusting the engine idling speedThe engine idling speed must be checked and, if
necessary, adjusted as follows at the intervals
specified in the periodic maintenance and lubrica-
tion chart.
1. V-belt case drain plugU2LC61E0.book Page 35 Wednesday, February 26, 2014 3:56 PM

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8
TIPA diagnostic tachometer is needed to make this
adjustment. 1. Start the engine and warm it up.TIPThe engine is warm when it quickly responds to
the throttle. 2. Remove panel C. (See page 8-10.)
3. Attach the tachometer to the spark plug lead.
4. Check the engine idling speed and, if neces-sary, adjust it to specification by turning the
throttle stop screw at the carburetor. To in-
crease the engine idling speed, turn the throt-
tle stop screw in direction (a), and to decrease
it, turn the screw in direction (b).
TIPIf the specified idling speed cannot be obtained as
described above, have a Yamaha dealer make the
adjustment. 5. Install the panel.1. Throttle stop screwEngine idling speed:1450–1550 r/min
U2LC61E0.book Page 36 Wednesday, February 26, 2014 3:56 PM