Yamaha YP125R, Service Manual

Page: 355 / 498

OIL PUMP (YP250R)
5-110
EAS24960
CHECKING THE OIL PUMP
1. Check:
• Oil pump drive gear
• Oil pump driven gear
• Oil pump housing
• Oil pump housing cover
Cracks/damage/wear
→
Replace the defec-
tive part(s).
2. Measure:
• Inner-rotor-to-outer-rotor-tip clearance “a”
• Outer-rotor-to-oil-pump-housing clearance
“b”
• Oil-pump-housing-to-inner-rotor-and-outer-
rotor clearance “c”
Out of specification
→
Replace the oil pump.
3. Check:
• Oil pump operation
Rough movement
→
Repeat steps (1) and
(2) or replace the defective part(s).
EAS25000
ASSEMBLING THE OIL PUMP
1. Lubricate:
• Inner rotor
• Outer rotor
2. Lubricate:
• Oil pump shaft
(with the recommended lubricant)
3. Install:
• Oil pump shaft “1”
• Pin “2”
TIP
When installing the oil pump shaft, align the pin
in the oil pump shaft with the groove “a” in the in-
ner rotor.
1. Inner rotor
2. Outer rotor
3. Oil pump housing
Inner-rotor-to-outer-rotor-tip
clearance
Less than 0.15 mm (0.0059 in)
Limit
0.23 mm (0.0091 in)
Outer-rotor-to-oil-pump-housing
clearance
0.013–0.036 mm (0.0005–0.0014
in)
Limit
0.106 mm (0.0042 in)
Oil-pump-housing-to-inner-and-
outer-rotor clearance
0.04–0.09 mm (0.0016–0.0035 in)
Limit
0.16 mm (0.0063 in)
Recommended lubricant
Engine oil
Recommended lubricant
Molybdenum disulfide grease