Yamaha WR250F(N) Owner's Service Manual page 402

1
3
2
4
OIL PUMP
INSPECTION
Oil pump
1. Inspect:
Oil pump drive gear 1
Oil pump drive shaft 2
Rotor housing 3
Oil pump cover 4
Cracks/wear/damage
2. Measure:
Tip clearance a
(between the inner rotor 1 and outer
rotor 2)
Side clearance b
(between the outer rotor 2 and rotor
housing 3)
Housing and rotor clearance c
(between the rotor housing 3 and
rotors 1 2)
Out of specification
pump assembly.
Tip clearance a:
0.12 mm or less
(0.0047 in or less)
<Limit>: 0.20 mm (0.008 in)
Side clearance b:
0.09 ~ 0.17 mm (0.0035 ~ 0.0067 in)
<Limit>: 0.24 mm (0.009 in)
Housing and rotor clearance c:
0.03 ~ 0.10 mm (0.0012 ~ 0.0039 in)
<Limit>: 0.17 mm (0.0067 in)
3. Check:
Unsmooth
or replace the defective parts.
4 - 68
ENG
Replace.
Replace the oil
Repeat steps #1 and #2