Yamaha YP250 Mobility Scooter User Manual


 
4-22
CYLINDER AND PISTON
ENG
NOTE:
NOTE:
NOTE:
YP******
PISTON AND PISTON RINGS REMOVAL
1. Remove:
SPiston pin circlip
1
SPiston pin
2
SPiston
3
Before removing the piston pin circlip, cover the
crankcase opening with a clean towel or rag to
prevent the circlip from falling into the crank-
case cavity.
2. Remove:
STop ring
S2nd ring
SOil ring
When removing the piston ring, open the end
gap of the ring by fingers, and push up the other
side of the ring.
YP402100
CYLINDER INSPECTION
1. Measure:
SCylinder bore
Out of specification ! Rebore or replace
D Measure the cylinder bore with a cylinder
bore gauge.
D Measure the cylinder bore in parallel to and at
right angles to the crankshaft. Then, find the
average of the measurements.
Cylinder bore:
69.000 69.005 mm
<Limit: 69.1 mm>
<Defferance limit between A, B
and C: 0.03 mm>
2. Measure:
SWarpage
Out of specification ! Replace.
Cylinder warpage limit:
0.03 mm