Yamaha YP250 Mobility Scooter User Manual


 
4-16
VALVES AND VALVE SPRINGS
ENG
NOTE:
CAUTION:
YP401150
VALVES AND VALVE SPRINGS REMOVAL
1. Remove:
SValve cotters
1
Attach a valve spring compressor and attach-
ment
2
between the valve spring retainer and
cylinder head to remove the valve cotters.
Do not compress so much as to avoid dam-
age to the valve spring.
Valve spring compressor:
90890-04019
Attachment:
90890-04108
YP******
VALVES AND VALVE SPRINGS INSPECTION
1. Measure:
SValve stem diameter
Out of specification ! Replace.
Valve stem diameter:
Intake:
5.975 5.990 mm
<Limit: 5.94 mm>
Exhaust:
5.960 5.975 mm
<Limit: 5.92 mm>
YP402010
2. Measure:
SRunout (valve stem)
Out of specification ! Replace.
Runout limit:
0.01 mm
YP402030
3. Measure:
SFree length (valve spring)
Out of specification ! Replace.
Valve spring free length:
Inner spring:
38.1 mm
<Limit: 36.1 mm>
Outer spring:
36.93 mm
<Limit: 35.0 mm>