Suzuki UF50 Service Manual page 44

PISTON PIN AND PIN BORE
Measure the piston pin bore inside diameter using the dial cali-
pers and the piston pin outside diameter using the micrometer. If
either is out of specification or the difference between the mea-
surements is more than their limits, replace the piston and pis-
ton pin with new ones.
09900-20605: Dial calipers
09900-20205: Micrometer (0 – 25 mm)
Piston pin bore I.D.
Service Limit: 10.030 mm
Piston pin O.D.
Service Limit: 9.980 mm
PISTON RING FREE END GAP AND PISTON RING END GAP
Measure the piston ring free end gap using vernier calipers. Then,
fit the piston ring squarely into the cylinder and measure the
piston ring end gap using a thickness gauge.
If any of the measurements exceed the service limit, replace the
piston ring with a new one.
09900-20101: Vernier calipers
Piston ring free end gap
Service Limit:
1st: 3.2 mm ... R
2nd: 3.4 mm ... R
09900-20803: Thickness gauge
Piston ring end gap
Service Limit: 0.80 mm
Measure the piston-ring-to-groove clearance using the thickness
gauge.
If any of the clearances are out of specification, clean the groove
of the piston and piston rings.
09900-20803: Thickness gauge
Piston-ring-to-groove clearance
Standard:
1st: 0.03 – 0.07 mm
2nd: 0.02 – 0.06 mm
ENGINE 3-15