TM 10-4320-344-24
4.4.14.3 Repair.
Do not use cleaning solvent without proper ventilation and clothing. Do not
smoke or use near open flame or excessive heat. Dry cleaning solvent is
potentially dangerous to personnel and property. Clean parts in a well-
ventilated area. Avoid inhalation of solvent fumes. Wear goggles and rubber
gloves to protect eyes and skin. Wash exposed skin thoroughly. Failure to
obey this warning may result in personal injury or death.
If chemical carbon solvent is used to clean parts, make sure it will not
damage aluminum pistons or bronze piston bushings.
If cleaning solvent does not remove carbon deposits, use chemical carbon
s o l v e n t.
a .
Clean all components with cleaning solvent and wire brush.
b .
Clean ring grooves on piston (10).
c .
Allow all components to thoroughly air dry.
d.
Using standard aligning fixture, check connecting rod (12) for distortion and
misalignment.
e .
Check screws (1), caps (2), and connecting rods (12) for cracks or damage.
f .
Check piston pin bushings (11) for scoring and wear. Measure diameter of
bushings (11). The measurement should be no larger than 1.2523 inches
(31.81 mm).
g .
Inspect piston pin (9) for wear or scoring. Inspect piston pin (9) for the
dimensions listed in Table 4-6.
Table 4-6. Pinton Pin Dimensions.
Dimension
Minimum
Maximum
Length
3.025 inches (76.835 mm)
3.035 (77.089 mm)
Diameter
1.2478 inches (31.694 mm)
1.2500 inches (31.750 mm)
Clearance in piston
0.0000 inches (0.000 mm)
0.0005 inches (0.0127 mm)
Clearance in connecting
0.0005 inches (0.0127 mm)
0.0012 inches (0.0305 mm)
rod
h.
Inspect pistons (10) for damaged ring grooves, scoring, or cracks. Remove
light scoring with emery cloth. Inspect piston (10) to the dimensions listed
in Table 4-7.
Table 4-7. Piston Dimensions, Model 609-A.
Dimension
Minimum
Maximum
Clearance in cylinder
0.0016 inches (0.0406 mm)
0.0024 (0.0610 mm)
bore - 4" Bohn
Piston pin bore
1.2490 inches (31.7246 mm) 1.2502 inches (31.7551 mm)
4-45
NOTE
