Yamaha Wr 450 F Owners Manual

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ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
EC4H4600
Bearing
1. Inspect:
Bearing
Rotate inner race with a finger.
Rough spot/seizure → Replace.
EC444400
Oil seal
1. Inspect:
Oil seal
Wear/damage → Replace.
ASSEMBLY AND INSTALLATION
EC4G5110
Oil seal
1. Install:
Oil seal 1 
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
Install the oil seal with its manufacture’s
marks or numbers facing inward.
Bearing
1. Install:
Bearing 1 
NOTE:
Install the bearing by pressing its outer race
parallel.
New 
						

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ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
EC4G5220
Impeller shaft
1. Install:
Impeller shaft 1 
Plain washer 2 
Impeller 3 
NOTE:
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 on the oil seal lip, bearing and
impeller shaft. And install the shaft while
turning it.
Hold the impeller shaft on its width across
the flats a with spanners, etc. and install the
impeller.
T R..14 Nm (1.4 m · kg, 10 ft · lb)
Crankcase cover (right)
1. Install:
Dowel pin 1 
O-ring 2 
Collar 3 
Gasket 4 New
2. Install:
Crankcase cover (right) 1 
Bolt
NOTE:
Apply the engine oil on the impeller shaft
end.
When installing the crankcase cover onto the
crankcase, be sure that the impeller shaft
end 2 aligns with the balancer end slot 3.
Tighten the bolts in stage, using a crisscross
pattern.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb) 
						

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ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
Kick crank
1. Install:
Kickstarter 1 
Plain washer
Bolt (kickstarter)
NOTE:
Install the kickstarter so that the distance a
between the kickstarter and the fuel tank is
12 mm (0.47 in) or more.
T R..33 Nm (3.3 m · kg, 24 ft · lb)
2. Install:
Oil hose 1 
Bolt (oil hose) 2 
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
3. Install:
Copper washer 1 
Oil delivery pipe 2 
Union bolt (M8) 3 
Union bolt (M10) 4 
New
T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)
Water pump housing
1. Install:
Dowel pin 1 
O-ring 2 New 
						

							 
4 - 61
ENG
 
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT) 
2. Install: 
 
Water pump housing   
1  
  
 
Bolt (water pump housing)   
2  
  
 
Plain washer   
3  
  
 
Coolant drain bolt   
4  
 
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
 
3. Install: 
 
O-ring 
 
Coolant pipe   
1  
  
 
Bolt (coolant pipe)   
2  
 
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
 
Oil filter  
1. Install: 
 
Oil filter   
1  
  
 
O-ring   
2  
  
 
Oil filter cover   
3  
  
 
Bolt (oil filter cover)
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb) 
						

							 
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ENG
 
BALANCER
BALANCER 
BALANCER 
Extent of removal: 
1 
 Balancer drive gear 
2  
 Balancer
Extent of removal Order Part name Q’ty Remarks 
BALANCER REMOVAL 
Preparation for removal Clutch housing Refer to “CLUTCH” section.
Crankcase cover (right)Refer to “OIL FILTER, WATER PUMP AND 
CRANKCASE COVER (RIGHT)” section.
Stator Refer to “AC MAGNETO AND 
STARTER CLUTCH” section.
1 Nut (primary drive gear) 1
Refer to “REMOVAL POINTS”.
2 Nut (balancer) 1
3 Lock washer 1
4 Primary drive gear 1
5 Balancer drive gear 1
6 Lock washer 1
7 Balancer driven gear 1
8 Balancer 1 Refer to “REMOVAL POINTS”.
2
1
2 
						

							 
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ENG
 
BALANCER 
REMOVAL POINTS
Balancer drive gear and balancer driven
gear  
1. Straighten the lock washer tab.
2. Loosen: 
 
Nut (primary drive gear)   
1  
  
 
Nut (balancer)   
2  
 
NOTE:
 
Place an aluminum plate  
a  
 between the teeth
of the balancer drive gear  
3  
 and driven gear 
4 
. 
Balancer 
1. Remove: 
 
Balancer  
1 
 
NOTE:
 
When removing the balancer shaft, align the
center of the balancer shaft weight  
a  
 along
the line connecting the centers of the crank- 
shaft and balancer shaft. 
INSPECTION
Primary drive gear, balancer drive gear and
balancer driven gear 
1. Inspect: 
 
Primary drive gear  
1  
  
 
Balancer drive gear  
2 
  
 
Balancer driven gear  
3 
 
Wear/damage  
→ 
 Replace. 
Balancer 
1. Inspect: 
 
Balancer
Cracks/damage  
→ 
 Replace. 
						

							 
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ENG
 
BALANCER 
ASSEMBLY AND INSTALLATION
Balancer, balancer drive gear and balancer
driven gear 
1. Install: 
 
Balancer  
1 
 
NOTE:
 
When installing the balancer shaft, align the
center of the balancer shaft weight  
a 
 along
the line connecting the centers of the crank- 
shaft and balancer shaft.
2. Install: 
 
Balancer driven gear  
1 
 
NOTE:
 
Install the balancer driven gear onto the bal-
ancer while aligning the punch mark  
a 
 on the
balancer driven gear with the lower spline  
b 
on the balancer end. 
3. Install: 
 
Balancer drive gear  
1 
NOTE:
Align the punched mark a on the balancer
drive gear with the punched mark b on the
balancer driven gear.
Align the punched mark c on the balancer
drive gear with the lower spline d on the
crankshaft.
4. Install:
Lock washer 1 
Nut (balancer) 2 
Primary drive gear 3 
Nut (primary drive gear) 4 
NOTE:
Install the primary drive gear with its stepped
side b facing the engine.
Place an aluminum plate a between the
teeth of the balancer drive gear 5 and
driven gear 6.
5. Bend the lock washer tab.
T R..50 Nm (5.0 m · kg, 36 ft · lb)
T R..75 Nm (7.5 m · kg, 54 ft · lb)
b3 
						

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ENGOIL PUMP
OIL PUMP
OIL PUMP
Extent of removal:1 Oil pump removal2 Oil pump disassembly
Extent of removal Order Part name Q’ty Remarks
OIL PUMP REMOVAL AND DIS-
ASSEMBLY
Preparation for removal Clutch housing Refer to “CLUTCH” section.
Crankcase cover (right)Refer to “OIL FILTER, WATER PUMP AND 
CRANKCASE COVER (RIGHT)” section.
1 Circlip 1
2 Plate washer 1
3 Oil pump drive gear 1
4 Oil pump assembly 1
5 Dowel pin 1
6 Outer rotor 2 1
7 Circlip 1
8 Inner rotor 2 1
9 Pin 1
10 Oil pump cover 1
11 Outer rotor 1 1
12Inner rotor 1
1
2
1 
						

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ENGOIL PUMP
Extent of removal Order Part name Q’ty Remarks
13 Pin 1
14 Washer 1
15 Oil pump drive shaft 1
16 Rotor housing 1
2 
						

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ENGOIL PUMP
INSPECTION
Oil pump
1. Inspect:
Oil pump drive gear
Oil pump driven gear
Rotor housing
Oil pump cover
Cracks/wear/damage → Replace.
2. Measure:
Tip clearance a 
Between the inner rotor 1 and the
outer rotor 2.
Tip clearance b 
Between the outer rotor 2 and the rotor
housing 3.
Out of specification → Replace the oil
pump.
Tip clearance a:
0.12 mm or less 
(0.0047 in or less)
: 0.20 mm (0.008 in)
Tip clearance b:
0.09 ~ 0.17 mm (0.0035 ~ 0.0067 in)
: 0.24 mm (0.009 in)
Side clearance c:
0.03 ~ 0.10 mm (0.0012 ~ 0.0039 in)
: 0.17 mm (0.007 in)
3. Check:
Unsmooth → Repeat steps #1 and #2
or replace the defective parts.
ASSEMBLY AND INSTALLATION
Oil pump
1. Install:
Oil pump drive shaft 1 
Washer 2 
Pin 3 
Inner rotor 1 4 
NOTE:
Apply the engine oil on the oil pump drive
shaft and inner rotor 1.
Fit the pin into the groove in the inner rotor 1.