2014 YAMAHA YZ450F Owners Manual

ENGINE REMOVAL
5-6
EAS1SL1197REMOVING 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.
EAS1SL1198REMOVING 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.
EAS1SL1199REMOVING 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.
EAS1SL1200
1 2
3

ENGINE REMOVAL
5-7
REMOVING 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.
EAS1SL1201CHECKING THE SILENCER AND EXHAUST
PIPE
1. Check:
•Gasket “1”
Damage  Replace.
EAS1SL1202CHANGING 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.
2. Remove:
•Rivet “1”
• Silencer cap “2”
1
1
1
a
1
2
2
1

ENGINE REMOVAL
5-8
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”.
EAS1SL1203INSTALLING THE ENGINE
1. Install: • Engine “1”Install the engine from the right side.
• Pivot shaft “2”
• Engine mounting bolt (lower side) “3”
• Front engine bracket “4”
• Engine bracket bolt (front side) “5”
• Engine mounting bolt (front side) “6”
• Upper engine bracket “7”
• Engine bracket bolt (upper side) “8”
• Engine mounting bolt (upper side) “9”
TIP
Apply molybdenum disulfide grease to the pivot
shaft.
Silencer body bolt
8 Nm (8.0 m·kgf, 5.8 ft·lbf)
LOCTITE®
1
T R..
a
1 2LT
2
1
Pivot shaft85 Nm (8.5 m·kgf, 61 ft·lbf)
Engine mounting bolt (lower side) 53 Nm (5.3 m·kgf, 38 ft·lbf)
Engine bracket bolt (front side) 34 Nm (3.4 m·kgf, 25 ft·lbf)
Engine mounting bolt (front side) 59 Nm (5.9 m·kgf, 43 ft·lbf)
Engine bracket bolt (upper side) 34 Nm (3.4 m·kgf, 25 ft·lbf)
Engine mounting bolt (upper
side) 45 Nm (4.5 m·kgf, 33 ft·lbf)
1
1
a233
T R..
T R..
T R..
T R..
T R..
T R..

ENGINE REMOVAL
5-9
EAS1SL1204INSTALLING THE BRAKE PEDAL
1. Install:
• Spring “1”
• Brake pedal “2”
• O-rings “3”
• Bolt (brake pedal) “4”
•Clip “5”
TIP
Apply the lithium soap base grease on the bolt,
O-rings and brake pedal bracket.
EAS1SL1205INSTALLING 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”
TIP
Tighten the nut while applying the rear brake.
ECA33DD040
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”
Bolt (brake pedal)
26 Nm (2.6 m·kgf, 19 ft·lbf)
M
78
9
9 8
7
4 1
2
43
5
56
New
T R..
1 2
3
45
LS
Nut (drive sprocket)
75 Nm (7.5 m·kgf, 54 ft·lbf)
Bolt (drive sprocket cover)
7 Nm (0.7 m·kgf, 5.1 ft·lbf)
New
T R..
T R..
21

ENGINE REMOVAL
5-10
EAS1SL1206INSTALLING THE EXHAUST PIPE AND
MUFFLER
1. Install:
•Gasket
• Exhaust pipe 1 “1”
• Nut (exhaust pipe 1) “2”
TIP
First temporarily tighten 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”
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.
Nut (exhaust pipe)
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
New
T R..
1
22
1
2
2mm (0.08in)
Bolt (silencer)
30 Nm (3.0 m·kgf, 22 ft·lbf)
Bolt (exhaust pipe 2)
20 Nm (2.0 m·kgf, 14 ft·lbf)
Clamp
12 Nm (1.2 m·kgf, 8.7 ft·lbf)
T R..
2
2
1
2mm (0.08in)
T R..
T R..

CAMSHAFT
5-11
EAS1SL1207
CAMSHAFT
Removing the cylinder head cover
OrderPart nameQ’tyRemarks
SeatRefer 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 tankRefer to “FUEL TANK” on page 7-1.
1Spark plug1
2Cylinder head breather hose1
3Bolt (cylinder head cover)3
4Cylinder head cover1
5Cylinder head cover gasket1
6Timing 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
5-12
Removing the camshaft
OrderPart nameQ’tyRemarks
1Timing mark accessing screw1
2Crankshaft end accessing screw1
3Timing chain tensioner cap bolt1
4Timing chain tensioner1
5Gasket1
6Camshaft cap bolt8
7Camshaft cap2
8Clip2
9Exhaust camshaft1
10Intake camshaft1
For installation, reverse the removal proce-dure.
6 Nm (0.6 m•kgf, 4.3 ft•Ibf)T.R.
6 Nm (0.6 m•kgf, 4.3 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.10 Nm (1.0 m•kgf, 7.2 ft•Ibf)T.R.
5
8
3
4
1
2
7
6
5 (4)(4)
6
M
M
E
New
New
New
E
E

CAMSHAFT
5-13
EAS1SL1208REMOVING 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.
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.
1
2
b
a
dc
1 2
1
2
3