Yamaha WR450F(S) Owner's Service Manual page 434

OIL PUMP
INSPECTION
Oil pump
1. Inspect:
Oil pump drive gear
G
Oil pump driven gear
G
Rotor housing
G
Oil pump cover
G
Cracks/wear/damage → Replace.
2. Measure:
Tip clearance a
G
Between the inner rotor 1 and the
outer rotor 2.
Tip clearance b
G
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)
<Limit>: 0.20 mm (0.008 in)
Tip clearance b:
0.09 ~ 0.17 mm (0.0035 ~ 0.0067 in)
<Limit>: 0.24 mm (0.009 in)
Side clearance c:
0.03 ~ 0.10 mm (0.0012 ~ 0.0039 in)
<Limit>: 0.17 mm (0.007 in)
3. Check:
Unsmooth → Repeat steps #1 and #2
G
or replace the defective parts.
ASSEMBLY AND INSTALLATION
Oil pump
1. Install:
Oil pump drive shaft 1
G
Washer 2
G
Pin 3
G
Inner rotor 1 4
G
NOTE:
Apply the engine oil on the oil pump drive
G
shaft and inner rotor 1.
Fit the pin into the groove in the inner rotor 1.
G
4 - 67
ENG