Checking The Oil Pump - Yamaha TW125 1999 Service Manual

OIL PUMP
REMOVING THE PRIMARY DRIVE GEAR
1. Straighten the lock washer tab.
2. Remove:
S nut (primary drive gear) 1
S lock washer 2
S primary drive gear 3
NOTE:
Place a folded aluminium plate or copper wash-
er a between the teeth of the balancer drive
gear 4 and balancer driven gear 5 .
EAS00364

CHECKING THE OIL PUMP

1. Check:
S primary drive gear 1
S oil pump driven gear 2
S oil pump housing 3
S oil pump housing cover 4
Cracks/damage/wear ! Replace the de-
fective part(-s).
2. Measure:
S inner-rotor-to-outer-rotor-tip clearance A
S outer-rotor-to-oil-pump-housing clearance
B
S oil-pump-housing-to-inner-rotor-and-outer-
rotor clearance C
Out of specification ! Replace the oil pump.
1 Inner rotor
2 Outer rotor
3 Oil pump housing
Inner-rotor-to-outer-rotor-tip cle-
arance
0.03 X 0.09 mm
<Limit 0.14 mm>
Outer-rotor-to-oil-pump-housing
clearance
0.10 X 0.15 mm
<Limit 0.35 mm>
Oil-pump-housing-to-inner-rotor-
and-outer-rotor clearance
0.03 X 0.09 mm
<Limit 0.14 mm>
3. Check:
S oil pump operation
Unsmooth ! Repeat steps (1) and (2) or re-
place the defective part(-s).
4-44
ENG