Yamaha YBR250 2007, Service Manual

Page: 241 / 361

ENG
OIL PUMP AND BALANCER GEAR
CHECKING THE OIL PUMP
1. Check:
• oil pump gear
Cracks/Damage/Wear --> Replace the
damaged part(s).
2. Measure:
• clearance
a
between the outer rotor and the
inner rotor
• clearance
b
between the outer rotor and the
oil pump crankcase
• clearance
c
between the oil pump
crankcase and the inner and outer rotors
Out of specification
--> Replace the oil
pump.
1
Inner rotor
2
Outer rotor
3
Oil pump housing
Clearance between the outer rotor
and inner rotor
0.15 mm (0.006 in)
<Limit.>: 0.2 mm (0.008 in)
Clearance between the outer rotor
and the oil pump crankcase
0.10 ~ 0.15 mm (0.004 ~0.006 in)
<Limit>: 0.20 mm (0.008 in)
Clearance between the oil pump
housing and the inner and outer
rotors
0.04 ~ 0.09 mm
(0.0016 ~ 0.0035 in)
<Limit>: 0.15 mm ( 0.006 in)
3. Check:
• oil pump operation
Improper movement --> Repeat steps 1 and
2 or replace the damaged part(s).
a
b
c
1
2
3
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