2016 YAMAHA YZ450F bolt pattern

TIGHTENING TORQUES
2-12
EAS20320
TIGHTENING TORQUES
EASB111055GENERAL TIGHTENING TORQUE SPECIFI-
CATIONS
This chart specifies tightening torques for stan-
dard fasteners with a standard ISO thread
pitch. Tightening torque specifications for spe-
cial components or assemblies are provided for
each chapter of this manual. To avoid warpage,
tighten multi-fastener assemblies in a criss-
cross pattern and progressive stages until the
specified tightening torque is reached. Unless
otherwise specified, tightening torque specifi-
cations require clean, dry threads. Compo-
nents should be at room temperature.
A. Distance between flats
B. Outside thread diameter
A (nut)B
(bolt)General tightening
torques
Nm m·kgf ft·lbf
10 mm 6 mm 6 0.6 4.3
12 mm 8 mm 15 1.5 11
14 mm 10 mm 30 3.0 22
17 mm 12 mm 55 5.5 40
19 mm 14 mm 85 8.5 61
22 mm 16 mm 130 13.0 94

FRONT WHEEL
4-5
EASB111124DISASSEMBLING THE FRONT WHEEL
1. Remove:
• Oil seals
• Bearings
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a. Clean the outside of the front wheel hub.
b. Remove the oil seals “1” with a flat-head
screwdriver.
TIP
To prevent damaging the wheel, place a rag “2”
between the screwdriver and the wheel sur-
face.
c. Remove the bearings with a bearing puller.
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EASB111125ASSEMBLING THE FRONT WHEEL
1. Install:
• Bearing (left side) “1”
• Spacer “2”
• Bearing (right side) “3”
• Oil seals “4”
TIP
• Apply the lithium-soap-based grease to the
bearing and the oil seal lip when installing.
• Left side of bearing shall be installed first.
• Install the oil seal with its manufacture’s
marks or numbers facing outward.
ECA
NOTICE
Install the bearing by pressing its outer race
parallel.
TIP
Use a socket “1” that matches the diameter of
the bearing outer race and that of the oil seal.
2. Install:
• Brake disc “1”
• Brake disc bolt “2”
TIP
Tighten the bolts in stages and in a crisscross
pattern.
12
New
Brake disc bolt
12 Nm (1.2 m·kgf, 8.7 ft·lbf)
LOCTITE®
4
3
2
1
4
New
New
1
T R..

REAR WHEEL
4-9
TIP
Tighten the self-locking nuts in stages and in a
crisscross pattern.
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EASB111132ASSEMBLING THE REAR WHEEL
1. Install:
• Bearing (right side) “1”
• Circlip “2”
• Spacer “3”
• Bearing (left side) “4”
• Oil seals “5”
TIP
• Apply the lithium-soap-based grease to the
bearing and the oil seal lip when installing.
• Install the bearing with seal facing outward.
• Right side of bearing shall be installed first.
• Install the oil seal with its manufacture’s
marks or numbers facing outward.
ECA
NOTICE
Install the bearing by pressing its outer race
parallel.
TIP
Use a socket “1” that matches the diameter of
the bearing outer race and that of the oil seal.2. Install:
• Brake disc “1”
• Brake disc bolt “2”
TIP
Tighten the bolts in stages and in a crisscross
pattern.
3. Install:
• Collar “1”
TIP
Apply the lithium-soap-based grease on the oil
seal lip.
New
New
5
43 1
25
LSLS
Brake disc bolt
14 Nm (1.4 m·kgf, 10 ft·lbf)
LOCTITE®
1
T R..
1
LS

REAR BRAKE
4-26
EASB111148INTRODUCTIONEWA
WARNING
If you need to disassemble the disc brake
components, observe the following precau-
tions.
• Never disassemble the brake components
unless absolutely necessary.
• If there is any problem with connections
on the hydraulic brake system, perform
the following jobs.
Disassemble the brake system, drain the
brake fluid, and clean it. After that, add a
suitable amount of brake fluid. Then, bleed
it after reassembly.
• Use only brake fluid for washing internal
brake components.
• Use new brake fluid for cleaning the brake
components.
• Immediately wipe off the spilled brake fluid
to avoid damage to painted surfaces or
plastic parts.
• Handle brake fluid with special care not to
let it enter your eyes so that you may not
lost your eyesight.
• FIRST AID FOR BRAKE FLUID ENTERING
THE EYES:
• Flush with water for 15 minutes and get
immediate medical attention.
EASB111149CHECKING THE REAR BRAKE DISC
1. Remove:
• Rear wheel
Refer to “REAR WHEEL” on page 4-7.
2. Check:
• Brake disc
Damage/galling  Replace.
3. Measure:
• Brake disc thickness
Measure the brake disc thickness at a few
different locations.
Out of specification  Replace.
Refer to “CHECKING THE FRONT BRAKE
DISC” on page 4-16.
4. Measure:
• Brake disc deflection
Out of specification  Correct the brake disc
deflection or replace the brake disc.5. Adjust:
• Brake disc deflection
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a. Remove the brake disc.
b. Turn the mounted position of the brake disc
by one bolt hole.
c. Install the brake disc.
TIP
Tighten the brake disc bolts in stages and in a
crisscross pattern.
d. Measure the brake disc deflection.
e. If out of specification, repeat the adjustment
steps until the brake disc deflection is within
specification.
f. If the brake disc deflection cannot be
brought within specification, replace the
brake disc.
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6. Install:
• Rear wheel
Refer to “REAR WHEEL” on page 4-7. Brake disc thickness limit
3.5 mm (0.14 in)
Brake disc runout limit (as mea-
sured on wheel)
0.15 mm (0.0059 in)
Brake disc bolt
14 Nm (1.4 m·kgf, 10 ft·lbf)
LOCTITE®
T R..

CAMSHAFT
5-14
EASB111207REMOVING THE CAMSHAFT
1. Remove:
• Timing mark accessing screw “1”
• Crankshaft end accessing screw “2”
2. Align:
• Alignment mark
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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
Align the alignment mark “c” on the exhaust
camshaft sprocket and the alignment mark “d”
on the intake camshaft sprocket with the edge
of the cylinder head.
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3. Remove:
• Timing chain tensioner cap bolt “1”
• Timing chain tensioner “2”
•Gaskets
4. Remove:
• Bolt (camshaft cap) “1”
• Camshaft cap “2”
• Clip “3”
TIP
• Remove the bolts (camshaft cap) in a criss-
cross pattern, working from the outside in.
• In order to prevent the clip from falling into the
crankcase, remove the camshaft cap.
ECA33DD027
NOTICE
The bolts (camshaft cap) must be removed
evenly to prevent damage to the cylinder
head, camshafts or camshaft caps.
1
2
b
a
dc
1 2
1
2
3

CAMSHAFT
5-16
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a. Install the camshaft into the cylinder head.
b. Position a strip of Plastigauge® “1” onto the
camshaft journal as shown.
c. Install the dowel pins and the camshaft
caps.
TIP
• Tighten the camshaft cap bolts in a crisscross
pattern from innermost to outer caps.
• Do not turn the camshaft when measuring the
camshaft journal-to-camshaft cap clearance.
d. Remove the camshaft caps and then mea-
sure the width of the Plastigauge® “1”.
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5. Measure:
• Camshaft journal diameter “a”
Out of specification  Replace the cam-
shaft.
Within specification  Replace the cylinder
head and the camshaft caps as a set.
EASB111209CHECKING THE TIMING CHAIN AND CAM-
SHAFT SPROCKET
1. Check:
• Timing chain “1”
Damage/stiffness  Replace the timing
chain and camshaft as a set.
2. Check:
• Camshaft sprocket
More than 1/4 tooth wear “a”  Replace the
camshaft and the timing chain as a set.
EASB111210CHECKING THE TIMING CHAIN TENSION-
ERS
1. Check:
• Timing chain tensioner
Crack/damage  Replace.
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a. While pressing the tensioner rod lightly with
your fingers, use a thin screwdriver “1” to
wind the tensioner rod up fully clockwise.
b. When releasing the screwdriver by pressing
lightly with your fingers, make sure that the
tensioner rod will come out smoothly. Camshaft cap bolts
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Camshaft journal diameter
21.959–21.972 mm (0.8645–
0.8650 in)
1
T R..
1
a. 1/4 tooth
b. Correct
1. Timing chain roller
2. Camshaft sprocket
a
b1
2

CYLINDER HEAD
5-22
EASB111214REMOVING THE CYLINDER HEAD
1. Remove:
• Cylinder head bolts
TIP
• Loosen the bolts in the proper sequence as
shown.
• Loosen each bolt 1/2 of a turn at a time. After
fully loosening all the bolts, remove them.
•M6  35 mm (1.38 in): “1” – “2”
• M10  149 mm (5.87 in): “3” – “6”
EASB111215CHECKING THE TIMING CHAIN GUIDE (IN-
TAKE SIDE)
1. Check:
• Timing chain guide (intake side)
Damage/wear  Replace.
EASB111216CHECKING THE CYLINDER HEAD
1. Eliminate:
• Combustion chamber carbon deposits
TIP
Use a rounded scraper, not a sharp instrument,
in order not to damage or scratch the spark
plug bore threads.2. Check:
• Cylinder head
Damage/scratches  Replace.
TIP
When replacing the cylinder head, replace also
the valve.
Refer to “CHECKING THE VALVE SEATS” on
page 5-28.
• Cylinder head coolant passages
Mineral deposits/rust  Eliminate.
3. Measure:
• Cylinder head warpage
Out of specification  Resurface the cylin-
der head.
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a. Place a straightedge and a thickness gauge
across the cylinder head.
b. Measure the warpage.
c. If the limit is exceeded, resurface the cylin-
der head as follows.
d. Place a 400–600 grit wet sandpaper on a
surface plate, and resurface the cylinder
head using a figure-eight sanding pattern.
TIP
To ensure an even surface, turn the cylinder
head several times.
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61
2
35
4 x2 x4FWD
Warpage limit
0.05 mm (0.0020 in)

CLUTCH
5-43
2. Check:
• Primary-drive-gear-to-primary-driven-gear
free play
Free play exists  Replace the primary
drive and primary driven gears as a set.
EASB111242CHECKING THE PRIMARY DRIVEN GEAR
1. Check:
• Primary driven gear
Damage/wear  Replace the primary drive
and primary driven gears as a set.
Excessive noise during operation  Re-
place the primary drive and primary driven
gears as a set.
EASB111243INSTALLING THE OIL SEAL
1. Install:
• Oil seal “1”
• Washer “2”
• Circlip “3”
TIP
• Apply is lithium-soap-based grease on the oil
seal lip.
• Install the oil seal in parallel with its manufac-
ture's marks or numbers facing inward.
EASB111244INSTALLING THE RIGHT CRANKCASE
COVER
1. Install:
• Dowel pin “1”
• O-rings “2”
• Collar “3”
• Gasket “4”
TIP
Apply the lithium-soap-based grease on the O-
ring.2. Install:
• Right crankcase cover “1”
• Right crankcase cover bolt “2”
TIP
• Apply the engine oil on the impeller shaft end.
• When installing the crankcase cover onto the
crankcase, make sure that the impeller shaft
end “3” aligns with the balancer end slot “4”.
• Tighten the right crankcase cover bolts in
stages and in a crisscross pattern.
New
New
3
2
1
LS
New
New
Right crankcase cover bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
1
1 4
2
New
New
3
LS
T R..
12