2016 YAMAHA WR 450F engine

ENGINE REMOVAL
6-3
Removing the electronic parts
OrderPart name Q’tyRemarks
Use a suitable stand to raise the front wheel
off the ground.
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
Air filter case cover
1 Rectifier/regulator 1
2ECU 1
3 Ignition coil 1
4 Neutral switch 1
5 AC magneto coupler 1 Disconnect.
6 Crankshaft position sensor coupler 1 Disconnect.
7 Coolant temperature sens or coupler1 Disconnect.
For installation, reverse the removal proce-
dure.
T.R.
T.R.
T.R.T.R.
7
3
6 5
1 4 2
LT
New
LS

ENGINE REMOVAL
6-4
Removing the engine
OrderPart name Q’tyRemarks
Use a suitable stand to raise the front wheel
off the ground.
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
Exhaust pipe and silencer Refer to “ENGINE REMOVAL” on page 6-1.
Air filter case Refer to “THROTTLE BODY” on page 8-7.
Throttle body Refer to “THROTTLE BODY” on page 8-7.
Clutch cable Refer to “CLUTCH” on page 6-41.
Shift pedal Refer to “SHIFT SHAFT” on page 6-53.
Starter motor Refer to “ELECTRIC STARTER” on page 6-
36.
1 Engine guard 1
2 Brake pedal 1
3Spring 1
4 Cylinder head breather hose 1
New
New
LS
M
8
8
76
11
4 5
New
1
10
3 2 9
55 Nm (5.5 m kgf, 40 ft Ibf)T.R.

ENGINE REMOVAL
6-5
5 Drive sprocket cover1
6 Drive chain guide 1
7 Drive sprocket 1
8 Upper engine bracket 2
9 Lower engine bracket 2
10 Pivot shaft 1
11 Engine 1
For installation, reverse the removal proce-
dure.
Removing the engine
Order Part name Q’tyRemarks
New
New
LS
M
8
8
76
11
4 5
New
1
10
3 2 9
55 Nm (5.5 m kgf, 40 ft Ibf)T.R.

ENGINE REMOVAL
6-6
EAS2GC1227REMOVING THE SILENCER
1. Remove:• Rear shock absorber assembly lower bolt “1”
• Connecting arm bolt (relay arm side) “2”
• Silencer “3”
TIP
Move the rear shock absorber to the left side of
the chassis, and remove the silencer.
EAS2GC1228REMOVING THE EXHAUST PIPE 2
1. Remove: • Starter motor
Refer to “ELECTRIC STARTER” on page 6-
36.
• Exhaust pipe 2
TIP
Put the Exhaust pipe 2 into the state as shown
by moving this, and then remove it.
EAS2GC1229REMOVING 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
6-7
EAS2GC1230REMOVING 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.
EAS2GC1231CLEANING THE SPARK ARRESTEREWA
WARNING
• Be sure the exhaust pipe and muffler are cool before cleaning the spark arrester.
• Do not start the engine when cleaning the
exhaust system.
1. Remove: • Muffler cap screws “1”
2. Remove: • Spark arrester bolts “1”
3. Remove: • Tail pipe “1”
• Tail pipe gasket “2”
• Spark arrester “3”Pull the spark arrester out of the muffler.
• Spark arrester gasket “4”
4. Clean: • Spark arresterTap the spark arrester lightly, then use a
wire brush to remove any carbon deposits.
1

ENGINE REMOVAL
6-8
5. Install:• Spark arrester gasket
• Spark arresterInsert the spark arrester into the muffler and
align the bolt holes.
• Tail pipe gasket
• Spark arrester bolts
6. Install: • Muffler cap
TIP
First tighten the two screws “a” located horizon-
tally apart, and then tighten the others.
EAS2GC1232CHECKING THE SILENCER AND EXHAUST
PIPE
1. Check:•Gasket “1”Damage  Replace.
EAS2GC1233INSTALLING 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.
Spark arrester bolt
9 Nm (0.9 m·kgf, 6.5 ft·lbf)
Muffler cap screw 5 Nm (0.5 m·kgf, 3.6 ft·lbf)
Pivot shaft 85 Nm (8.5 m·kgf, 61 ft·lbf)
New
New
T R..
T R..
1
1
T R..
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) 55 Nm (5.5 m·kgf, 40 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)
T R..
T R..
T R..
T R..
T R..
M
78
9
9
8
7
4
1
2
4 3
5
5
6

ENGINE REMOVAL
6-9
EAS2GC1234INSTALLING 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.
EAS2GC1235INSTALLING 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.
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”
EAS2GC1236INSTALLING 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).
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 4 5
LS
New
T R..
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..
2 1
New
T R..

ENGINE REMOVAL
6-10
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.
Bolt (silencer) 30 Nm (3.0 m·kgf, 22 ft·lbf)
1
2 2
1
2
2mm (0.08in)
T R..
Bolt (exhaust pipe 2) 20 Nm (2.0 m·kgf, 14 ft·lbf)
Clamp 12 Nm (1.2 m·kgf, 8.7 ft·lbf)
1
22
2mm (0.08in)
T R..
T R..