Removing The Balancer Weight Gear And Oil Pump; Checking The Oil Pump; Checking The Balancer Weight Gear - Yamaha XG250 Service Manual

EAS4D601
REMOVING THE BALANCER WEIGHT GEAR
AND OIL PUMP
1. Straighten the lock washer tab.
2. Remove:
Balancer weight gear nut
●
Lock washer
●
Balancer weight gear
●
NOTE:
Place the aluminum plate "a" between balancer
drive gear "1" and balancer weight gear "2", and
then loosen the balancer weight gear nut "3".
a
3. Remove:
Oil pump assembly
●
EAS24960

CHECKING THE OIL PUMP

1. Check:
Oil pump driven gear
●
Oil pump housing
●
Oil pump 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
●
"b"
Oil-pump-housing-to-inner-rotor-and-out-
●
er-rotor clearance "c"
Out of specification → Replace the oil pump.
OIL PUMP AND BLANCER WEIGHT GEAR
1
2
3
clearance
Inner-rotor-to-outer-rotor-tip clear-
ance
0.150 mm (0.0059 in)
Limit
0.20 mm (0.0079 in)
Outer-rotor-to-oil-pump-housing
clearance
0.010–0.034 mm (0.0004–0.0013
in)
Limit
0.050 mm (0.0020 in)
Oil-pump-housing-to-in-
ner-and-outer-rotor clearance
0.04–0.09 mm (0.0016–0.0035 in)
Limit
0.15 mm (0.0059 in)
1. Inner rotor
2. Outer rotor
3. Oil pump housing
3. Check:
Oil pump operation
●
Rough movement → Repeat steps (1) and
(2) or replace the defective part(s).
EAS4D602

CHECKING THE BALANCER WEIGHT GEAR

1. Check:
Balancer weight gear
●
Buffer boss
●
Compression spring
●
Dowel pin
●
Cracks/damage/wear → Replace.
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