2016 YAMAHA WR 450F engine

WATER PUMP
7-4
EAS2GC1332
WATER PUMP
Removing the water pump
OrderPart name Q’tyRemarks
Coolant Drain.
Refer to “CHANGING THE COOLANT” on
page 3-10.
Engine oil Drain.
Refer to “CHANGING THE ENGINE OIL” on
page 3-17.
Right crankcase cover Refer to “CLUTCH” on page 6-41.
1 Water pump housing 1
2 Dowel pin 2
3Gasket 1
4Collar 1
5Pin 1
6 Impeller shaft assembly 1
7 Oil seal 1
8 Bearing 1
9 Oil seal 1
For installation, reverse the removal proce-
dure.
LS
LS
7
6
2 2
3
1
854
New
New
New
E
9
New
E
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.

WATER PUMP
7-5
EAS2GC1333REMOVING THE OIL SEAL
TIP
• Remove the oil seal when the coolant level changes frequently more than usual, coolant
has discolored, or engine oil has become
milky.
• Do not use the removed oil seal.
1. Remove:• Oil seals “1”
EAS2GC1334CHECKING THE WATER PUMP
1. Check:
• Water pump housing cover
• Impeller shaftCracks/damage/wear  Replace.
EAS2GC1335CHECKING THE BEARING
1. Check:
• BearingRotate the inner race with your finger.
Rough spot/seizure  Replace.
EAS2GC1336INSTALLING THE OIL SEAL
1. Install:
• Oil seals “1”
TIP
• Apply the lithium-soap-based grease on the oil seal lip.
• Install the oil seal with its manufacture’s marks or numbers facing the right crankcase
cover “2”. 2. Install:
• Bearing “1”
TIP
Install the bearing by pressing its outer race
parallel.
EAS2GC1337ASSEMBLING THE WATER PUMP
1. Install:
• Impeller shaft assembly “1”
•Pin “2”
• Collar “3”
• Circlip “4”
TIP
• Take care so that the oil seal lip is not dam-aged or the spring does not slip off its posi-
tion.
• When installing the impeller shaft, apply the engine oil to the oil seal lip, the bearing, and
the impeller shaft.
1
1
New
1
1New
New
LS
LS2
New
4
1
23New
E

FUEL TANK
8-1
EAS2GC1338
TIP
This section is intended for those who have basic knowledge and skill concerning the servicing of
Yamaha motorcycles (e.g., Yamaha dealers, serv ice engineers, etc.). Those who have little knowl-
edge and skill concerning servicing are requested not to undertake inspection, adjustment, disas-
sembly, or reassembly only by reference to this manual. It may lead to servicing trouble and
mechanical damage.
EAS2GC1339
FUEL TANK
Removing the fuel tank
OrderPart name Q’tyRemarks
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right)
Air scoop (left/right)
1 Fuel pump coupler 1 Disconnect.
2 Fuel hose 1 Disconnect.
3Fuel tank 1
4 Fuel pump bracket 1
5 Fuel pump 1
6 Fuel pump gasket 1
7 Fuel sender 1
4(6)
(2)
(2)
(2) (2)2
5
6
3
1
New
4.0 Nm (0.40 m kgf, 2.9 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
9 Nm (0.9 m kgf, 6.5 ft Ibf)T.R.
4.0 Nm (0.40 m kgf, 2.9 ft Ibf)T.R.
4.0 Nm (0.40 m kgf, 2.9 ft Ibf)T.R.
7

FUEL TANK
8-5
TIP
• Insert the fuel hose into the fuel pipe securely until you hear a “click”.
• Slide the fuel hose connector cover “1” at the hose end in the direction of the arrow.
• Install the fuel hose connector holder “a”.
• Check that the fuel hose and the fuel pump
lead are routed through the guide on the cov-
er.
3. Connect: • Fuel pump coupler
4. Install: • Air scoop (left/right)
• Seat
• Side cover (left/right)Refer to “GENERAL CHASSIS” on page 5-
1.
EAS2GC1348CHECKING THE FUEL PRESSURE
1. Check:• Fuel pressure
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Remove the side cover (left/right), the seat and the air scoop (left/right).
Refer to “GENERAL CHASSIS” on page 5-
1.
b. Remove the fuel tank bolt and lift the fuel
tank.
c. Disconnect the fuel hose from the fuel pump.
Refer to “REMOVING THE FUEL TANK” on
page 8-3.
EWA
WARNING
Cover the fuel hose connection with a cloth
when disconnecting it. This is because re-
sidual pressure in the fuel hose could cause
fuel to spurt out when the hose is removed.
ECA
NOTICE
Make sure that the fuel hose is disconnect-
ed by hand. Do not forcibly disconnect the
hose with tools.
d. Connect the pressure gauge “1” and the fuel pressure adapter “2” to the fuel hose.
e. Start the engine.
f. Measure the fuel pressure. Out of specification  Replace the fuel
pump.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS2GC1349CHECKING THE DAMPER
1. Check:
• Damper 1 “1”
• Damper 2 “2”
• Damper 3 “3”Wear/damage  Replace.
TIP
• Affix dampers 1 and 3 with the arrow on each
damper pointing outward.
• Affix the damper 2 with its projection “a” facing
the rear of the vehicle.
1
a
Pressure gauge 90890-03153
Pressure gauge YU-03153
Fuel pressure adapter 90890-03186
Fuel pressure adapter YM-03186
Fuel line pressure (at idle) 300.0–390.0 kPa (3.00–3.90 kgf/
cm
2, 43.5–56.6 psi)
1
2

THROTTLE BODY
8-7
EAS2GC1351
THROTTLE BODY
Removing the throttle body
OrderPart name Q’tyRemarks
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.
ECU Refer to “ENGINE REMOVAL” on page 6-1.
Ignition coil Refer to “ENGINE REMOVAL” on page 6-1.
1 Intake air temperature sensor coupler 1 Disconnect.
2 Breather hose 3 1
3 Air filter case 1
4 Fuel injector coupler 1 Disconnect.
5 Intake air pressure sensor coupler 1 Disconnect.
6 Throttle position sensor coupler 1 Disconnect.
7 Throttle cable cover 1
8 Throttle cable 2
3
1
2
7
11
12
10
9
4
8
6
5
3.5 Nm (0.35 m kgf, 2.5 ft Ibf)T.R.
3.5 Nm (0.35 m kgf, 2.5 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
3.0 Nm (0.30 m kgf, 2.2 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.

THROTTLE BODY
8-10
EAS2GC1352CHECKING THE INJECTOR
1. Check:• InjectorsObstruction  Replace, and check the fuel
pump and the fuel injection system.
Refer to “FUEL INJECTION SYSTEM” on
page 9-28.
Deposits  Replace.
Damage  Replace.
2. Check:
• Injector resistanceRefer to “CHECKING THE FUEL INJEC-
TOR” on page 9-81.
EAS2GC1353CHECKING THE THROTTLE BODY
1. Check:• Throttle bodyCracks/damage  Replace.
2. Check:
• Fuel passagesObstructions  Clean.
ECA
NOTICE
• Before removing the throttle body, clean
the area around the throttle body to pre-
vent dirt and other foreign material from
falling into the engine.
• If the throttle body is subject to strong shocks or dropped during cleaning, re-
place it.
• Do not use any caustic carburetor clean- ing solution.
• Do not directly push the throttle valves to open them.
• Do not loosen the throttle valve stopper screw “1”, throttle valve pulley nut “2”, or
throttle valve screw “3”. A loss of perfor-
mance may occur.
• Do not use compressed air to clean the throttle body. Foreign materials may ad-
here to the intake air pressure sensor pas-
sage “a” and fuel injector “b” in the
throttle body. 3. Check:
• Starter knob/idle screw passage “c”Obstruction  Blow out with compressed
air.
EAS2GC1354CHECKING THE THROTTLE BODY JOINT
1. Check: • Throttle body joint “1”Crack/damage  Replace.
1
2
3
ba
c
1

9-1
EAS2GC1357
TIP
This section is intended for those who have basic knowledge and skill concerning the servicing of
Yamaha motorcycles (e.g., Yamaha dealers, serv ice engineers, etc.). Those who have little knowl-
edge and skill concerning servicing are requested not to undertake inspection, adjustment, disas-
sembly, or reassembly only by reference to this manual. It may lead to servicing trouble and
mechanical damage.

IGNITION SYSTEM
9-3
1. Joint connector
2. Joint connector
4. AC magneto
9. Battery
10.Frame ground
11.Starter relay
12.Main fuse
22.ECU (engine control unit)
23.Ignition coil
24.Spark plug
30.Joint connector
35.Lean angle sensor
36.Engine stop switch
48.Frame ground
49.Ignition coil sub-lead
50.Negative battery lead