engine YAMAHA YFZ450 2012 Service Manual

8-19
8
12. Install the crankcase engine oil drain bolt, the
engine oil tank drain bolt and their new gasket,
and then tighten the bolts to the specified
torques.
13. Refill with the specified amount of the recom- mended engine oil through the engine oil tank
filler hole, and then install and tighten the en-
gine oil tank filler cap.
14. Refill with the specified amount of the recom- mended engine oil through the crankcase en-
gine oil filler hole, and then install and tighten
the crankcase engine oil filler cap.
TIPBe sure to wipe off spilled oil on any parts after the
engine and exhaust system have cooled down.NOTICEECB00300
In order to prevent clutch slippage (since the
engine oil also lubricates the clutch), do not
mix any chemical additives. Do not use oils
with a diesel specification of “CD ” or oils of
Tightening torques:
Crankcase engine oil drain bolt:20 Nm (2.0 m ·kgf, 14 ft ·lbf)
Engine oil tank drain bolt: 19 Nm (1.9 m ·kgf, 14 ft ·lbf)Recommended oil:
See page 10-1.
Oil quantity: Without oil filter element replacement:Quantity in oil tank: 1.55 L (1.64 US qt, 1.36 Imp.qt)
Quantity in crankcase: 0.20 L (0.21 US qt, 0.18 Imp.qt)
With oil filter element replacement: Quantity in oil tank: 1.55 L (1.64 US qt, 1.36 Imp.qt)
Quantity in crankcase: 0.30 L (0.32 US qt, 0.26 Imp.qt)
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8-20
8a higher quality than specified. In addition,
do not use oils labeled
“ENERGY CONSERV-
ING II” or higher.

Make sure that no foreign material enters the
crankcase.15. Start the engine, and then let it idle for several
minutes while checking it for oil leakage. If oil
is leaking, immediately turn the engine off and
check for the cause.
16. Turn the engine off, and then check the oil lev- el and correct it if necessary.
17. Install the engine guard by installing the bolts, and then tighten them to the specified torque.
NOTICE: Be sure to apply LOCTITE
® to the
engine guard bolts before installing them.
[ECB00371] EBU23470
Coolant The coolant level should be checked before each
ride. In addition, the coolant must be changed at
the intervals specified in the periodic maintenance
and lubrication chart.EBU27942To check the coolant level
1. Place the ATV on a level surface.TIPThe coolant level must be checked on a cold en-
gine since the level varies with engine tempera-
ture.2. Check the coolant level in the coolant reser- voir.TIPThe coolant should be between the minimum and
maximum level marks.
Tightening torque:Engine guard bolt:7 Nm (0.7 m ·kgf, 5.1 ft ·lbf)
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8-21
8
3. If the coolant is at or below the minimum level
mark, remove the coolant reservoir cap, add
coolant or distilled water to the maximum level
mark, and then install the reservoir cap.
NOTICE: If coolant is not available, use
distilled water or soft tap water instead. Do
not use hard water or salt water since they
are harmful to the engine. If water has
been used instead of coolant, replace it
with coolant as soon as possible, other-
wise the cooling system will not be pro- tected 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.
[ECB01011]
TIP
The radiator fan is automatically switched on or
off according to the coolant temperature in the
radiator.
If the engine overheats, see page 8-58 for fur-
ther instructions.EBU23564To change the coolant
WARNING
EWB01890Wait for the engine and radiator to cool before
removing the radiator cap. You could be
burned by hot fluid and steam blown out under
1. Maximum level mark
2. Minimum level mark
3. Coolant reservoir
4. Coolant reservoir cap
1
2 4
3
Coolant reservoir capacity (up to the maxi-
mum level mark):
0.29 L (0.31 US qt, 0.26 Imp.qt)
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8-22
8pressure. 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 panel A. (See page 8-9.)
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.)
4. Remove the radiator cap. 5. Remove the coolant reservoir by removing the
bolts.
6. Remove the coolant reservoir cap, and then turn the coolant reservoir upside down to
empty it.1. Coolant drain bolt
2. Gasket
3. Trough
12
3
1. Radiator cap
1
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8-23
8
7. After draining the coolant, thoroughly flush the
cooling system with clean tap water.
8. Install the coolant reservoir by installing the bolts.
9. Install the coolant drain bolt and its new gas- ket, and then tighten the bolt to the specified
torque. 10. Pour the recommended coolant into the reser-
voir to the maximum level mark, and then in-
stall the reservoir cap. NOTICE: Mix
antifreeze with distilled water only. Howev-
er, 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.
[ECB00991]
11. Pour the recommended coolant into the radia- tor until it is full.
12. Install the radiator cap, start the engine, let it idle for several minutes, and then turn it off.
1. Coolant reservoir cap
2. Coolant reservoir
3. BoltTightening torque:Coolant drain bolt:10 Nm (1.0 m ·kgf, 7.2 ft· lbf)
1
3
2
Antifreeze/water mixture ratio:1:1
Recommended antifreeze: High-quality ethylene glycol antifreeze con-
taining corrosion inhibitors for aluminum en-
gines
Coolant quantity: Radiator capacity (including all routes):1.30 L (1.37 US qt, 1.14 Imp.qt)
Coolant reservoir capacity (up to the maxi-
mum level mark): 0.29 L (0.31 US qt, 0.26 Imp.qt)
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8-24
813. 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.
14. Start the engine, and then check for coolant leakage.
TIPIf any leakage is found, have a Yamaha dealer
check the cooling system.15. Install the panel.EBU23707Cleaning the air filter element The 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
riding 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 4-12.)
3. Remove the air filter case cover by unhookingthe holders.1. Air filter case check hose
1
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8-26
88. 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.
[EWB01941]
9. Squeeze the excess solvent out of the sponge material and let it dry. NOTICE: Do not twist
the sponge material when squeezing it.
[ECB00441]
10. Check the sponge material and replace it if damaged.
11. 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.12. Pull the sponge material over the air filter ele-ment frame.
13. Apply all-purpose grease to the air filter ele- ment seat.
1. Sponge material
2. Air filter element frame
1
2
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8-27
8
14. Install the washer onto the air filter element
frame, and then insert the wing bolt into the
hole in the air filter element frame. NOTICE:
Be sure to install the washer with its
curved side facing outward as shown.
[ECB00453]
15. Insert the air filter element into the air filter case, and then tighten the wing bolt. NOTICE:
Make sure that the air filter element is
properly seated in the air filter case. Never
operate the engine with the air filter ele-
ment removed. This will allow unfiltered air
to enter the engine, causing rapid engine
wear and possible engine damage. Addi-
tionally, operation without the air filter ele-
ment will affect carburetor jetting with
subsequent poor performance and possi-
ble engine overheating.
[ECB00461]
16. Install the air filter case cover by hooking the holders onto the air filter case.
1. Air filter element seat
1
1. Washer
1
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8-28
817. 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 ar-
eas. Each time the air filter element maintenance
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 fit-
tings securely to avoid the possibility of unfiltered
air entering the engine.EBU27703Cleaning the spark arrester Select a well-ventilated area free of combustible
materials and make sure the exhaust and muffler
are cool. 1. Remove the tailpipe bolt. 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
1
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8-29
8
4. Insert the tailpipe into the muffler and align the
bolt holes.
5. Install the bolt and tighten it to the specified torque.
6. Remove the purging bolt and the gasket. 7. Start the engine and rev it up approximately
twenty times while momentarily creating ex-
haust system back pressure by blocking the
end of the muffler with a shop towel.
8. Stop the engine and allow the exhaust pipe to cool.
9. Check the gasket for damage, and replace it if necessary.
10. Install the gasket and the purging bolt, and then tighten the bolt to the specified torque.
1. Tailpipe
2. Spark arresterTightening torque:Tailpipe bolt:10 Nm (1.0 m ·kgf, 7.2 ft· lbf)
1
2
1. Purging bolt
2. Gasket
1
2
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