2016 YAMAHA YZ450F lock

ENGINE
3-12
2. Adjust:
• Throttle grip free play
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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.
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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
3-16
d. Install the oil strainer.
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6. Install:
• Engine oil drain bolt
• Drain bolt
7. Pour the specified amount of engine oil into
the oil filler cap hole.
8. Install:
• Oil filler cap
9. Check:
• Oil level
Refer to “CHECKING THE ENGINE OIL
LEVEL” on page 3-14.
10.Check:
• Engine oil pressure
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a. Slightly loosen the oil pressure check bolt
“1”.
EWA
WARNING
When the engine is started with the check
bolt removed, oil will spout; therefore, al-
ways loosen it before the checkup.
Start the engine and keep it idling until oil
starts to seep from the oil pressure check
bolt.
EWA
WARNING
Always keep the engine idling speed during
the checkup without increasing the engine
speed.
ECA
NOTICE
If no engine oil seeps out after one minute,
immediately turn the engine off so it will not
seize.
b. If no engine oil seeps out, check the engine
oil for leaks, and the engine oil passage and
the oil pump for damage.
c. Check the oil pressure again.
d. Tighten the oil pressure check bolt.
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TIP
• Because the air pressure is lower at high alti-
tudes, the air-fuel mixture will become richer.
If the idling speed is low, turn the starter knob/
idle screw a few clicks counterclockwise to in-
crease the speed before the adjustment.
• Before adjusting the engine idling speed,
make sure that the air filter element is not
clogged, the engine compression is proper,
and the throttle grip free play is proper.
• Adjust the engine idling speed with the starter
knob/idle screw pushed in completely. Oil strainer bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Drain bolt
20 Nm (2.0 m·kgf, 14 ft·lbf)
Engine oil quantity
With oil filter element replace-
ment
0.69 L (0.73 US qt, 0.61 Imp.qt)
Quantity (disassembled)
0.95 L (1.00 US qt, 0.84 Imp.qt)
1
2New
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New
T R..
Oil pressure check bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
1
T R..

ENGINE
3-18
3. Remove:
• Timing mark accessing screw “1”
• Crankshaft end accessing screw “2”
• O-ring
4. Check:
• Valve clearance
Out of specification  Regulate.
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a. Turn the crankshaft counterclockwise with a
wrench.
b. Align the top dead center (TDC) mark “a” on
the rotor with the alignment mark “b” on the
crankcase cover.
TIP
Check that the alignment mark “c” on the cam-
shaft sprocket and the alignment mark “d” on
the intake camshaft sprocket are aligned with
the edge of the cylinder head.c. Measure the valve clearance “e” using a
thickness gauge “1”.
TIP
Record the measured reading if the clearance
is incorrect.
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5. Adjust:
• Valve clearance
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a. Remove the camshaft (intake and exhaust).
Refer to “CAMSHAFT” on page 5-12.
b. Remove the valve lifter “2” and the adjusting
pad “3” with a valve lapper “1”.
TIP
• Place a cloth in the timing chain space to pre-
vent adjusting pads from falling into the crank-
case.
• Identity each valve lifter and adjusting pad po-
sition very carefully so that they can be rein-
stalled in their original place. Valve clearance (cold)
Intake
0.13–0.20 mm (0.0051–0.0079 in)
Exhaust
0.18–0.25 mm (0.0071–0.0098 in)
1
2
b
a
dc
ee
1

CHASSIS
3-23
EASB111090CHECKING THE BRAKE HOSE
1. Check:
• Brake hose “1”
Cracks/damage/wear  Replace.
2. Check:
• Brake hose clamp
Loose Connection  Tighten the clamp bolt.
3. Stand the vehicle upright and apply the front
brake and the rear brake several times.
4. Check:
• Brake hoses
Brake fluid leaks  Replace the damaged
brake hose.
Refer to “FRONT BRAKE” on page 4-12.
Refer to “REAR BRAKE” on page 4-22.
EASB111091ADJUSTING THE FRONT BRAKE
1. Check:
• Brake lever position “a”2. Remove:
• Brake lever cover
3. Adjust:
• Brake lever position
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a. Loosen the locknut “1”.
b. Turn the adjusting bolt “2” in direction “a” or
“b” until the specified brake lever position is
obtained.
c. Tighten the locknut.
EWA13050
WARNING
A soft or spongy feeling in the brake lever
can indicate the presence of air in the brake
system. Before the vehicle is operated, the
air must be removed by bleeding the brake
system. Air in the brake system will consid-
erably reduce braking performance.
ECA13490
NOTICE
After adjusting the brake lever position,
make sure there is no brake drag.
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A. Front
B. Rear
Brake lever position
95 mm (3.74 in)
Extent of adjustment
86–105 mm (3.39–4.13 in)
1
1
Direction “a”
Brake lever position is increased.
Direction “b”
Brake lever position is decreased.
Locknut
5 Nm (0.5 m·kgf, 3.6 ft·lbf)
a
b
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CHASSIS
3-24
4. Install:
• Brake lever cover
EASB111092ADJUSTING THE REAR BRAKE
1. Check:
• Brake pedal position “a”
(distance from the top of the rider footrest to
the top of the brake pedal)
Out of specification  Regulate.
2. Adjust:
• Brake pedal position
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a. Loosen the locknut “1”.
b. Turn the adjusting bolt “2” in direction “a” or
“b” until the specified brake pedal position is
obtained.
c. Tighten the locknut.
EWA
WARNING
A soft or spongy feeling in the brake pedal
can indicate the presence of air in the brake
system. Before running, bleed the brake
system. Air in the brake system will cause
braking performance to be reduced.
ECA
NOTICE
After adjusting the brake pedal position,
make sure that there is no brake drag.
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EASB111093CHECKING THE FRONT BRAKE PADS
1. Measure:
• Brake pad thickness “a”
Out of specification  Replace as a set.
TIP
The pads worn up to the indicator “b” grooves
mean that the brake pad thickness limit is
reached. Brake pedal position
0.0 mm (0.00 in)
Direction “a”
Brake pedal is raised.
Direction “b”
Brake pedal is lowered.
Locknut
6 Nm (0.6 m·kgf, 4.3 ft·lbf)
1 2
a
b
T R..
Brake pad lining thickness (inner)
4.4 mm (0.17 in)
Limit
1.0 mm (0.04 in)
Brake pad lining thickness (outer)
4.4 mm (0.17 in)
Limit
1.0 mm (0.04 in)
a
b
a

CHASSIS
3-28
2. Check:
• Brake fluid level
The minimum level mark “a” or below 
Add.
EWA
WARNING
• Use only the designated brake fluid. Other
brake fluids may cause the rubber seals to
deteriorate, causing leakage and poor
brake performance.
• Refill with the same type of brake fluid that
is already in the system. Mixing brake flu-
ids may result in a harmful chemical reac-
tion, leading to poor brake performance.
• When refilling, be careful that water does
not enter the brake fluid reservoir. Water
will significantly lower the boiling point of
the brake fluid and could cause vapor
lock.
ECA
NOTICE
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
EASB111097ADJUSTING THE DRIVE CHAIN SLACKECA13550
NOTICE
A drive chain that is too tight will overload
the engine and other vital parts, and one
that is too loose can skip and damage the
swingarm or cause an accident. Therefore,
keep the drive chain slack within the speci-
fied limits.1. Use a suitable stand to raise the rear wheel
off the ground.
EWA13120
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Shift the transmission into the neutral posi-
tion.
3. Pull the drive chain up above the drive chain
guide installation bolt with a force of about
50 N (5.0 kgf, 36 lbf).
4. Check:
• Drive chain slack “a”
Out of specification  Regulate.
TIP
Measure drive chain slack between the drive
chain guide and the bottom of the chain as
shown.
5. Adjust:
• Drive chain slack
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a. Loosen the wheel axle nut “1”.
b. Loosen both locknuts “2”.
c. Turn the adjusting bolt “3” in direction “a” or
“b” until the specified drive chain slack is ob-
tained. Specified brake fluid
DOT 4
A. Front brake
B. Rear brake
Drive chain slack
50–60 mm (1.97–2.36 in)
Direction “a”
The drive chain slack decreases.
Direction “b”
The drive chain slack increases.
a

CHASSIS
3-29
TIP
• To maintain the proper wheel alignment, ad-
just both sides evenly.
• Push the rear wheel forward to make sure that
there is no clearance between the swingarm
end plates and the ends of the swingarm.
d. Tighten the locknut.
e. Tighten the wheel axle nut.
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EASB111098CHECKING THE FRONT FORK LEGS
1. Stand the vehicle upright on a level surface.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Check:
• Inner tube
Damage/scratches  Replace.
• Front fork leg (s)
Oil leaks between inner tube and outer tube
 Replace the oil seal.
3. Hold the vehicle upright and apply the front
brake.
4. Check:
• Front fork operation
Push down hard on the handlebar several
times and check if the front fork rebounds
smoothly.
Unsmooth operation  Correct or replace.
Refer to “FRONT FORK” on page 4-38.
EASB111099CHECKING THE FRONT FORK PROTEC-
TOR GUIDE
1. Check:
• Protector guide “1”
Out of specification  Replace.
TIP
The protector guide reaches the limit of its use
when it is worn down to the same height “a” as
of the outer tube circumference.
EASB111100CLEANING THE FRONT FORK OIL SEAL
AND DUST SEAL
1. Remove:
•Protector
• Dust seal “1”
ECA
NOTICE
Be careful not to damage the dust seal and
the inner tube by a driver. Locknut
21 Nm (2.1 m·kgf, 15 ft·lbf)
Wheel axle nut
135 Nm (13.5 m·kgf, 98 ft·lbf)
1
32
a
b
T R..
T R..1
a
1

CHASSIS
3-32
2. Adjust:
• Spring preload
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a. Loosen the locknut “1”.
b. Loosen the adjuster “2” until there is some
clearance between the spring and the ad-
juster.
c. Measure the spring free length “a”.
d. Turn the adjuster in the direction of “b” or “c”
to make an adjustment.
TIP
• Be sure to remove all dirt and mud from
around the locknut and adjusting ring before
adjustment.
• The length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjusting ring.e. Tighten the locknut.
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3. Install:
• Rear frame
Refer to “REAR SHOCK ABSORBER AS-
SEMBLY” on page 4-55.
Rebound damping
ECA@
NOTICE
Do not turn the adjuster forcibly beyond its
adjusting range.
1. Adjust:
• Rebound damping
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a. Turn the adjuster “1” in the direction of “a” or
“b” to make an adjustment. Direction “b”
Spring preload is increased (suspen-
sion is harder).
Direction “c”
Spring preload is decreased (suspen-
sion is softer).
Spring preload adjusting positions
Minimum
Position in which the spring is
turned in 1.5 mm (0.06 in) from
its free length.
Standard
Position in which the spring is
turned in 10 mm (0.39 in) from its
free length.
Maximum
Position in which the spring is
turned in 18 mm (0.71 in) from its
free length.
Locknut
30 Nm (3.0 m·kgf, 22 ft·lbf)
Direction “a”
Rebound damping is increased (sus-
pension is harder).
Direction “b”
Rebound damping is decreased (sus-
pension is softer).
Rebound damping adjusting posi-
tions
Maximum
Fully turned in
Standard
14 clicks out* (USA) (CAN)
12 clicks out* (EUR) (JPN) (AUS)
(NZL) (ZAF)
Minimum
30 clicks out*
* With the adjuster fully turned
c
b
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