YAMAHA YZ450F 2016 Owners Manual

ENGINE REMOVAL
5-6
EASB111196REMOVING THE SILENCER
1. Remove:
• Rear shock absorber assembly lower bolt
“1”
• Connecting arm bolt (frame side) “2”
• Silencer “3”
TIP
Move the rear shock absorber to the left side of
the chassis, and remove the silencer.
EASB111197REMOVING THE EXHAUST PIPE 2
1. Remove:
• Exhaust pipe 2
TIP
Put the Exhaust pipe 2 into the state as shown
by moving this, and then remove it.
EASB111198REMOVING THE DRIVE SPROCKET
1. Straighten the lock washer tab.
2. Remove:
• Nut (drive sprocket) “1”
• Lock washer “2”
TIP
Loosen the nut while applying the rear brake.
3. Remove:
• Drive sprocket “1”
• Drive chain “2”
TIP
Remove the drive sprocket together with the
drive chain.
1 2
3

ENGINE REMOVAL
5-7
EASB111199REMOVING THE ENGINE
1. Remove:
• Pivot shaft “1”
TIP
If the pivot shaft is pulled all the way out, the
swingarm will come loose. If possible, insert a
shaft of similar diameter into the other side of
the swingarm to support it.
2. Remove:
• Engine “1”
From the right side.
TIP
• Make sure that the couplers, the hoses, and
the cables are disconnected.
• Lift up the engine, and remove this from its
lower part toward the right of the chassis.
EASB111200
CHECKING THE SILENCER AND EXHAUST
PIPE
1. Check:
•Gasket “1”
Damage  Replace.
EASB111201CHANGING THE SILENCER FIBER
1. Remove:
•Bolt “1”
• Silencer body “2”
ECA33DD026
NOTICE
Do not hit the silencer stay “a” as it may do
damage to the silencer.
TIP
Remove the inner pipe while holding the silenc-
er in place with a vise etc.
1
1
1
a
1
2

ENGINE REMOVAL
5-8
2. Remove:
•Rivet “1”
• Silencer cap “2”
3. Replace:
• Fiber “1”
4. Install:
• Silencer body “1”
•Bolt “2”
TIP
Apply heat-resistant sealant to the areas “a”
shown, making sure that there are no gaps in
the beads of sealant.5. Replace:
•Fiber “1”
TIP
Stuff the fiber into the silencer body by using a
flat board “2”.
6. Install:
• Silencer cap “1”
•Rivet “2”
TIP
• Apply heat-resistant sealant to the areas “a”
shown, making sure that there are no gaps in
the beads of sealant.
• Take care not to allow the fiber out of place
when installing the silencer body “3”.
EASB111202INSTALLING THE ENGINE
1. Install:
• Engine “1”
Install the engine from the right side.
• Pivot shaft “2”
• Engine mounting bolt (lower side) “3” Silencer body bolt
8 Nm (0.8 m·kgf, 5.8 ft·lbf)
LOCTITE®
2
1
1
T R..
a
12LT
Pivot shaft
85 Nm (8.5 m·kgf, 61 ft·lbf)
Engine mounting bolt (lower side)
53 Nm (5.3 m·kgf, 38 ft·lbf)
2
1
1
1 a233
T R..
T R..

ENGINE REMOVAL
5-9
• Front engine bracket “4”
• Engine bracket bolt (front side) “5”
• Engine mounting bolt (front side) “6”
•Patch “7”
• Upper engine bracket “8”
• Engine bracket bolt (upper side) “9”
• Engine mounting bolt (upper side) “10”
TIP
• Apply molybdenum disulfide grease to the
pivot shaft.
• Install the patch with the claw “a” facing inside
the chassis.
EASB111203
INSTALLING THE BRAKE PEDAL
1. Install:
• Spring “1”
• Brake pedal “2”
• O-rings “3”
• Bolt (brake pedal) “4”
• Clip “5”
TIP
Apply the lithium-soap-based grease on the
bolt, O-rings and brake pedal bracket.
EASB111204INSTALLING THE DRIVE SPROCKET
1. Install:
• Drive sprocket “1”
• Drive chain “2”
TIP
Install the drive sprocket together with the drive
chain.
2. Install:
• Lock washer “1”
• Nut (drive sprocket) “2” Engine bracket bolt (front side)
34 Nm (3.4 m·kgf, 25 ft·lbf)
Engine mounting bolt (front side)
55 Nm (5.5 m·kgf, 40 ft·lbf)
Engine bracket bolt (upper side)
36 Nm (3.6 m·kgf, 26 ft·lbf)
Engine mounting bolt (upper
side)
45 Nm (4.5 m·kgf, 33 ft·lbf)
T R..
T R..
T R..
T R..
M
87 9
10
10 9
87
4 1
a
2
43
5
56
Bolt (brake pedal)
26 Nm (2.6 m·kgf, 19 ft·lbf)
Nut (drive sprocket)
75 Nm (7.5 m·kgf, 54 ft·lbf)
New
T R..
1 2
3
45
LS
New
T R..

ENGINE REMOVAL
5-10
TIP
Tighten the nut while applying the rear brake.
ECA
NOTICE
Make sure to tighten to specification; other-
wise, it may damage the other part that is
fastened together.
3. Bend the lock washer tab to lock the nut.
4. Install:
• Drive sprocket guide
• Drive sprocket cover “1”
• Bolt (drive sprocket cover) “2”
EASB111205INSTALLING THE EXHAUST PIPE AND
MUFFLER
1. Install:
•Gasket
• Exhaust pipe 1 “1”
• Nut (exhaust pipe 1) “2”
TIP
First temporarily tighten all nuts to 7 Nm (0.7
m·kgf, 5.1 ft·lbf). Then retighten them to 10 Nm
(1.0 m·kgf, 7.2 ft·lbf).2. Install:
•Clamp
• Exhaust pipe 2 “1”
• Bolt (exhaust pipe 2) “2”
TIP
Install and temporarily tighten the exhaust pipe
2 with its end positioned as shown with respect
to the exhaust pipe 1.
3. Install:
•Clamp
• Silencer “1”
• Bolt (silencer) “2” Bolt (drive sprocket cover)
7 Nm (0.7 m·kgf, 5.1 ft·lbf)
Nut (exhaust pipe)
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
T R..
21
New
T R..
Bolt (silencer)
30 Nm (3.0 m·kgf, 22 ft·lbf)
1
22
1
2
2mm (0.08in)
T R..

ENGINE REMOVAL
5-11
TIP
Install and temporarily tighten the silencer so
that its joint is positioned as shown with respect
to the exhaust pipe 2.
4. Tighten:
• Bolt (exhaust pipe 2)
•Clamp
TIP
Tighten while checking that their front and rear
joints are inserted in position.Bolt (exhaust pipe 2)
20 Nm (2.0 m·kgf, 14 ft·lbf)
Clamp
12 Nm (1.2 m·kgf, 8.7 ft·lbf)
2
2
1
2mm (0.08in)
T R..
T R..

CAMSHAFT
5-12
EASB111206
CAMSHAFT
Removing the cylinder head cover
Order Part name Q’ty Remarks
Seat Refer to “GENERAL CHASSIS” on page 4-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 4-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 4-1.
Fuel tank Refer to “FUEL TANK” on page 7-1.
1 Spark plug 1
2 Cylinder head breather hose 1
3 Bolt (cylinder head cover) 3
4 Cylinder head cover 1
5 Cylinder head cover gasket 1
6 Timing chain guide (top side) 1
For installation, reverse the removal proce-
dure.
31
4
6
5 3
2
3
10 Nm (1.0 mkgf, 7.2 ftIbf)T.R
.
13 Nm (1.3 mkgf, 9.4 ftIbf)T.R
.

CAMSHAFT
5-13
Removing the camshaft
Order Part name Q’ty Remarks
1Timing mark accessing screw
1
2Crankshaft end accessing screw
1
3Timing chain tensioner cap bolt
1
4Timing chain tensioner
1
5Camshaft cap
2
6Clip
2
7Intake camshaft
1
8Exhaust camshaft
1
For installation, reverse the removal proce-
dure.
LS
6 Nm (0.6 m kgf, 4.3 ft Ibf)T.R.
5
8
3
4
1
2
7
6
5 (4)(4)
6
M
M
E
New
New
New
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
6 Nm (0.6 m kgf, 4.3 ft Ibf)T.R.
LS
E
E

CAMSHAFT
5-14
EASB111207REMOVING THE CAMSHAFT
1. Remove:
• Timing mark accessing screw “1”
• Crankshaft end accessing screw “2”
2. Align:
• Alignment mark
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
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.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
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
5-15
5. Remove:
• Exhaust camshaft “1”
• Intake camshaft “2”
TIP
Attach a wire “3” to the timing chain to prevent
it from falling into the crankcase.
EASB111208CHECKING THE CAMSHAFT
1. Check:
• Camshaft lobes
Blue discoloration/pitting/scratches  Re-
place the camshaft.
2. Measure:
• Camshaft lobe dimensions “A” and “B”
Out of specification  Replace the cam-
shaft.3. Measure:
• Camshaft runout
Out of specification  Replace.
4. Measure:
• Camshaft-journal-to-camshaft-cap clear-
ance
Out of specification  Measure the cam-
shaft journal diameter. Camshaft lobe dimensions
Lobe height (Intake)
37.630–37.730 mm (1.4815–
1.4854 in)
Limit
37.620 mm (1.4811 in)
Base circle diameter (Intake)
27.950–28.050 mm (1.1004–
1.1043 in)
Limit
27.940 mm (1.0000 in)
Lobe height (Exhaust)
33.870–33.970 mm (1.3335–
1.3374 in)
Limit
33.860 mm (1.3331 in)
Base circle diameter (Exhaust)
24.711–24.811 mm (0.9729–
0.9768 in)
Limit
24.701mm (0.9725 in)
1
2
3
Camshaft runout limit
0.030 mm (0.0012 in)
Camshaft-journal-to-camshaft-
cap clearance
0.028–0.062 mm (0.0011–0.0024
in)