HYOSUNG COMET 125 Service Manual page 61

PISTON PIN HOLE BORE
Using a dial calipers, measure the piston pin hole bore
both in the vertical and horizontal directions.
If the measurement exceeds the service limit, replace
the piston.
Piston pin hole
bore
15.030 mm (0.5917 in) 13.030 mm (0.513 in)
Dial calipers : 09900-20605
PISTON PIN DIAMETER INSPECTION
Using a micrometer, measure the piston pin outside
diameter at three position, both the ends and the center.
If any of the measurements is founds less than the ser-
vice limit, replace the pin.
Piston pin
diameter
14.980 mm(0.5898 in) 13.980 mm(0.550 in)
Micrometer(0~25 mm) : 09900-20201
PISTON RING FREE END GAP
INSPECTION
Before installing piston rings, measure the free end gap
of each ring using vernier calipers. If the gap is less than
the service limit, replace the ring.
Piston ring free
end gap
1st
7.2 mm (0.284 in)
2nd
5.8 mm (0.228 in)
Piston ring free
end gap
1st
5.7 mm (0.224 in)
2nd
4.6 mm (0.181 in)
Vernier calipers : 09900-20101
PISTON RING END GAP INSPECTION
Insert the piston ring squarely into the cylinder using the
piston head.
Measure the end gap with a thickness gauge.
If the gap exceeds the service limit, replace the piston ring.
Piston ring end gap
(Assembly condition)
0.20~0.32 mm
1st
(0.008~0.013 in)
0.20~0.32 mm
2nd
(0.008~0.013 in)
Service limit
Service limit
Standard
5.0 mm (0.197 in)
6.0 mm (0.236 in)
Service limit
4.0 mm (0.158 in)
4.8 mm (0.189 in)
Standard
0.10~0.25 mm
(0.004~0.010 in)
0.25~0.40 mm
(0.010~0.016 in)
ENGINE 3-24