TM 5-3810-307-24-1-2
Use new piston rings and a feeler gauge to measure for
ring groove wear.
Replace the piston if the gaps are worn larger than the
dimensions listed below.
Ring to Groove Clearance
mm
in
Piston Ring (Top)
0.05
MIN
[0.002]
0.11
MAX
[0.005]
Piston Ring (2nd)
0.05
MIN
[0.002]
0.11
MAX
[0.005]
Piston Ring (Oil)
0.05
MIN
[0.002]
0.10
MAX
[0.004]
Measure the piston pin bore.
Replace the piston if the bore is worn larger than 17.49
mm [0.689-inch].
Inspect the cylinder bore of the crankcase for scoring or
other damage.
If the cylinder bore is damaged, bore or hone the
cylinder for oversized piston and rings.
Use a dial bore gauge, Part No. 3375072, to measure
the cylinder bore diameter.
Measure at 25.0 mm [1.00 inch] below the top of the
crankcase.
Maximum out-of-round is 0.038 mm [0.0015-inch].
Cylinder Bore
mm
in
92.08
MIN
[3.625]
92.16
MAX
[3.628]
If the crankcase bore is not within specifications, bore
the cylinder to use oversize piston and rings.
Change-1 12-39