2016 YAMAHA YZ450F check engine

PRE-OPERATION INSPECTION AND MAINTENANCE
3-7
EASB111066
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
EASB111067GENERAL INSPECTION AND MAINTENANCE
TIP
Perform usual maintenance enough so that, in the race course, a confirmation of that and simple set-
ting adjustments may only be left, in order to get enough time to use effectively.ITEM inspect Page
CoolantCheck that coolant is filled up to the radiator cap.
Check the cooling system for leakage.3-8 – 10
FuelCheck that a fresh gasoline is filled in the fuel tank.
Check the fuel line for leakage.1-21
Engine oilCheck that the oil level is correct. Check the crank-
case and oil line for leakage.3-14 – 16
Gear shifter and clutchCheck that gears can be shifted correctly in order and
that the clutch operates smoothly.3-10 – 11
Throttle grip/HousingCheck that the throttle grip operation and free play
are correctly adjusted. Lubricate the throttle grip and
housing, if necessary.3-11 – 12
BrakesCheck the play of front brake and effect of front and
rear brake.3-22 – 28
Drive chainCheck drive chain slack and alignment. Check that
the drive chain is lubricated properly.3-28 – 29
4-66 – 67
WheelsCheck for excessive wear and tire pressure. Check
for loose spokes and have no excessive play.3-34
SteeringCheck that the handlebar can be turned smoothly and
have no excessive play.3-35 – 36
Front forks and rear
shock absorberCheck that they operate smoothly and there is no oil
leakage.3-29 – 33
Cables (wires)Check that the clutch and throttle cables move
smoothly. Check that they are not caught when the
handlebars are turned or when the front forks travel
up and down.—
Exhaust pipeCheck that the exhaust pipe is tightly mounted and
has no cracks.3-14
Rear wheel sprocketCheck that the rear wheel sprocket tightening bolt is
not loose.4-8 – 9
Lubrication Check for smooth operation. Lubricate if necessary. 3-12, 3-36
Bolts and nutsCheck the chassis and engine for loose bolts and
nuts.1-24 – 25
Lead connectorsCheck that the AC magneto, ECU and ignition coil are
connected tightly.1-10 – 12
SettingsIs the machine set suitably for the condition of the rac-
ing course and weather or by taking into account the
results of test runs before racing? Are inspection and
maintenance completely done?10-1 – 8

ENGINE
3-8
EASB111068
ENGINE
EASB111069CHECKING THE COOLANT LEVELEWA1DX1003
WARNING
If coolant seems hot, do not remove the ra-
diator cap.
1. Stand the vehicle upright on a level surface.
2. Remove:
• Radiator cap “1”
3. Check:
• Coolant level
Maximum level “a” or below  Add coolant
up to the maximum level.
ECA1DX1004
NOTICE
• Adding water instead of coolant lowers the
antifreeze content. If, therefore, water is
used instead of coolant, check, and if nec-
essary, adjust the antifreeze concentra-
tion.
• Use only distilled water. However, if dis-
tilled water is not available, soft water may
be used.
4. Start the engine, warm this up for several
minutes, and then stop it.
5. Check:
• Coolant level
TIP
Before checking the coolant level, wait a few
minutes until the coolant has settled.
EASB111070CHECKING THE COOLING SYSTEM
1. Remove:
• Seat
• Side cover (left/right)
• Air scoop (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
• Air filter case cover
Refer to “THROTTLE BODY” on page 7-5.
2. Check:
• Radiator
• Radiator hoses
Crack/damage  Replace.
Refer to “RADIATOR” on page 6-1.
3. Install:
• Air filter case cover
Refer to “THROTTLE BODY” on page 7-5.
• Air scoop (left/right)
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
EASB111071CHANGING THE COOLANTEWA1DX1004
WARNING
If coolant seems hot, do not remove the ra-
diator cap.
1. Place a container under the engine.
2. Remove:
• Coolant drain bolt “1”
3. Remove:
• Radiator cap
Slowly loosen the radiator cap to drain cool-
ant.
TIP
When the radiator cap is loosened, coolant will
gush out transversely; therefore, bring the con-
tainer near to the outlet.
4. Thoroughly flush the cooling system with
clean tap water.
1. Radiator
1

ENGINE
3-9
5. Install:
• Copper washer
• Coolant drain bolt
6. Pour coolant.
EWA13040
WARNING
• If coolant splashes in your eyes, thorough-
ly wash them with water and consult a
doctor.
• If coolant splashes on your clothes, quick-
ly wash it away with water and then with
soap and water.
• If coolant is swallowed, induce vomiting
and get immediate medical attention.
ECA13480
NOTICE
• Adding water instead of coolant lowers the
antifreeze content of the coolant. If water
is used instead of coolant check, and if
necessary, correct the antifreeze concen-
tration of the coolant.
• Use only distilled water. However, if dis-
tilled water is not available, soft water may
be used.
• If coolant comes into contact with painted
surfaces, immediately wash them with wa-
ter.
• Do not mix different types of antifreeze.
7. Install:
• Radiator cap
8. Start the engine, warm this up for several
minutes, stop it, and then wait for it to cool
down.
9. Check:
• Coolant level
Refer to “CHECKING THE COOLANT LEV-
EL” on page 3-8.
EASB111072CHECKING THE RADIATOR CAP
1. Check:
• Seal (radiator cap) “1”
• Valve and valve seat “2”
Crack/damage  Replace.
Exist fur deposits  Clean or replace.
EASB111073CHECKING THE RADIATOR CAP VALVE
OPENING PRESSURE
1. Check:
• Radiator cap valve opening pressure
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a. Install the radiator cap tester adapter “2” and
the radiator cap tester “3” to the radiator cap
“1,” and activate the tester to check whether
it can stay for 5 to 10 seconds within stan-
dard pressure values.
TIP
Before attaching the cap to the tester, apply
water to its sealing surface.
No stay  Replace. Coolant drain bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Recommended coolant
High quality ethylene glycol
anti-freeze containing anti-cor-
rosion for aluminum engine
Radiator (including all routes)
1.04 L (1.10 US qt, 0.92 Imp.qt)
Coolant mixing ratio
1:1 (Coolant:Water)
New
T R..
Radiator cap valve opening pres-
sure
108–137 kPa (1.08–1.37 kg/cm
2,
15.7–19.9 psi)
Radiator cap tester
90890-01325
Mityvac cooling system tester kit
YU-24460-A
Radiator cap tester adapter
90890-01352
Pressure tester adapter
YU-33984

ENGINE
3-10
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EASB111074CHECKING THE COOLANT CIRCULATORY
SYSTEM FOR LEAKS
1. Check:
• Coolant level
2. Install:
• Radiator cap tester “1”
• Adapter “2”
3. Activate the tester to apply the test pressure.
ECA@
NOTICE
• Do not apply such a high pressure as ex-
ceeds the test pressure.
• Make sure that a checkup after the cylin-
der head gasket is replaced is made after 2
to 3 minutes of warm-up.
• Make sure that coolant is filled up to the
upper level beforehand.4. Check:
• Pressure value
No stay for 5 to 10 seconds at the test pres-
sure value  Correct.
• Radiator
• Radiator hose connections
Coolant leaks  Correct or replace.
• Radiator hoses
Bulges  Replace
EWA@
WARNING
When the radiator cap tester is removed,
coolant will spout; therefore, cover it with a
cloth beforehand.
EASB111075ADJUSTING THE CLUTCH LEVER POSI-
TION
1. Adjust:
• Clutch lever position “a”
Loosen the locknut “1” and use the adjuster
“2” to adjust the clutch lever position “a” as
desired.
2. Tighten:
• Locknut Radiator cap tester
90890-01325
Mityvac cooling system tester kit
YU-24460-A
Radiator cap tester adapter
90890-01352
Pressure tester adapter
YU-33984
Test pressure value
196 kPa (1.96 kg/cm
2, 27.9 psi)
Locknut
4.8 Nm (0.48 m·kgf, 3.5 ft·lbf)
1
2
a
T R..

ENGINE
3-11
EASB111076ADJUSTING THE CLUTCH LEVER FREE
PLAY
1. Check:
• Clutch lever free play “a”
Out of specification  Regulate.
2. Adjust:
• Clutch lever free play
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
Handlebar side
a. Turn the adjuster “1” in direction “a” or “b”
until the specified clutch lever free play is ob-
tained.
TIP
If the clutch lever free play cannot be obtained
on the handlebar side, use the adjuster on the
clutch cable side.
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Clutch cable side
a. Slide the clutch cable cover.
b. Loosen the locknut “1”.
c. Turn the adjuster “2” in direction “a” or “b”
until the specified clutch lever free play is ob-
tained.
d. Tighten the locknut “1”.
e. Return the clutch cable cover to its original
position.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EASB111077ADJUSTING THE THROTTLE GRIP FREE
PLAY
TIP
Prior to adjusting throttle grip free play, the en-
gine idling speed should be adjusted.
1. Check:
• Throttle grip free play “a”
Out of specification  Regulate. Clutch lever free play
7.0–12.0 mm (0.28–0.47 in)
Direction “a”
Clutch lever free play is increased.
Direction “b”
Clutch lever free play is decreased.a b
1
Direction “a”
Clutch lever free play is increased.
Direction “b”
Clutch lever free play is decreased.
Locknut
4.3 Nm (0.43 m·kgf, 3.1 ft·lbf)
Throttle grip free play
3.0–5.0 mm (0.12–0.20 in)
T R..
1a
b
2
b

ENGINE
3-12
2. Adjust:
• Throttle grip free play
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Loosen the locknut “1”.
b. Turn the adjuster “2” until the specified free
play is obtained.
c. Tighten the locknut.
EWA
WARNING
After adjusting the throttle grip free play,
turn the handlebar to the right and to the left
to ensure that this does not cause the en-
gine idling speed to change.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EASB111078LUBRICATING THE THROTTLE CABLE
1. Remove:
• Cover (throttle cable cap) “1”
• Cover (grip cap) “2”
• Throttle grip cap “3”
2. Lubricate:
• Throttle cable end “a” 3. Install:
• Throttle grip cap
• Screw (throttle grip cap)
4. Install:
• Cover (grip cap)
• Cover (throttle cable cap)
EWA
WARNING
Check that the throttle grip moves smooth-
ly. If this does not move smoothly, correct
the installed positions.
EASB111079CLEANING THE AIR FILTER ELEMENT
1. Remove:
• Fuel tank cap cover “1”
Refer to “FUEL TANK CAP” on page 1-20.
• Air filter case cover “2”
TIP
Loosen the quick fastener screw “3” and re-
move the air filter case cover.
2. Remove:
• Air filter mounting bolt “1”
• Air filter element “2”
• Air filter guide “3” (from the air filter element) Direction “a”
Throttle grip free play is increased.
Direction “b”
Throttle grip free play is decreased.
Recommended lubricant
Lithium-soap-based grease
1 2
b
a
Screw (throttle grip cap)
3.8 Nm (0.38 m·kgf, 2.8 ft·lbf)
T R..
1
2
3
3
3

ENGINE
3-13
3. Wash:
• Air filter element
EWA
WARNING
Do not use gasoline or organic (acid/alka-
line) volatile oil for washing.
TIP
After washing the element with air filter cleaner
or kerosene, squeeze and dry it completely.
ECA
NOTICE
Do not twist the element when squeezing
the element.
4. Check:
• Air filter element
Damage  Replace.
5. Foam-air-filter oil or equivalent oil to the ele-
ment
TIP
Squeeze out the excess oil. Element should be
wet but not dripping.
6. Install:
• Air filter guide “1” (to the air filter element)
• Air filter element “2”
• Air filter mounting bolt “3”7. Install:
• Air filter case cover “1”
TIP
Align the air filter case cover groove “a” with the
air filter case edge “b”.
8. Install:
• Fuel tank cap cover
EASB111080CHECKING THE THROTTLE BODY JOINT
1. Check:
• Throttle body joint
Refer to “CHECKING THE THROTTLE
BODY JOINT” on page 7-8.
EASB111081CHECKING THE BREATHER HOSES
1. Check:
• Breather hose “1”
Crack/damage  Replace.
Loose connection  Connect properly.
ECA14920
NOTICE
Make sure the cylinder head breather hose
is routed correctly. Oil application quantify
50 g
Air filter mounting bolt
2.0 Nm (0.20 m·kgf, 1.4 ft·lbf)
13
2
T R..
31
2
a
b 1
1

ENGINE
3-14
EASB111082CHECKING THE EXHAUST SYSTEM
1. Remove:
• Exhaust pipe protector
2. Check:
• Exhaust pipe 1
• Exhaust pipe 2
• Silencer
Crack/damage  Replace.
Refer to “ENGINE REMOVAL” on page 5-1.
• Exhaust gas
Leaks  Replace the gasket.
Refer to “ENGINE REMOVAL” on page 5-1.
3. Check:
• Tightening torques
4. Install:
• Exhaust pipe protectorEASB111083CHECKING THE FUEL LINE
1. Remove:
• Seat
• Side cover (left/right)
• Air scoop (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
• Fuel tank
Refer to “FUEL TANK” on page 7-1.
2. Check:
• Fuel hose “1”
Crack/damage  Replace.
Loose connection  Connect properly.
3. Install:
• Fuel tank
Refer to “FUEL TANK” on page 7-1.
• Air scoop (left/right)
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 4-
1.
EASB111084CHECKING THE ENGINE OIL LEVEL
1. Stand the vehicle upright on a level surface.
2. Start the engine, warm this up for 2–3 min-
utes, and then stop the engine and wait
about 1 minute.
3. Check:
• Oil level
Make sure that the engine oil level is above
the minimum level mark “a” shown for the oil
level check window “1”, and that the engine
oil does not come out by removing the oil
check bolt “2”.
The minimum level mark “a” or below  Add
the engine oil until its level exceeds the min-
imum level mark “a”.
Engine oil coming out of the oil check bolt 
Drain it until its last drop is out. Exhaust pipe bolt 1 and nut “1”
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Exhaust pipe 1 and exhaust pipe
2 bolt “2”
12 Nm (1.2 m·kgf, 8.7 ft·lbf)
Exhaust pipe 2 and silencer bolt
“3”
12 Nm (1.2 m·kgf, 8.7 ft·lbf)
Silencer and silencer bracket bolt
“4”
30 Nm (3.0 m·kgf, 22 ft·lbf)
Exhaust pipe protector screw
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
LOCTITE®
T R..
2
1
4
3
T R..
1