INSPECTION
Cylinders
Inspect cylinder walls for scratches, roughness, or ridges which
indicate excessive wear. If cylinder bore is very rough or deeply
scratched, or ridged, rebore cylinder and use oversize piston.
Using a cylinder gauge, measure cylinder bore in thrust and ax-
ial directions at two positions as shown in figure.
If any of following conditions is noted, rebore cylinder.
1) Cylinder bore dia. exceeds limit.
2) Difference of measurements at two positions exceeds taper
limit.
3) Difference between thrust and axial measurements exceeds
out-of-round limit.
Cylinder bore dia. limit: 74.15 mm (2.9196 in.)
Tapper and out-of-round limit: 0.10 mm (0.0039 in.)
NOTE:
If any one of four cylinders has to be rebored, rebore all
four to the same next oversize. This is necessary for the
sake of uniformity and balance.
“a”: 50 mm (1.96 in.)
“b”: 95 mm (3.74 in.)
Pistons
Inspect piston for faults, cracks or other damaged.
Damaged or faulty piston should be replaced.
Piston diameter:
As indicated in figure, piston diameter should be measured at a
position 23 mm (0.91 in.) from piston skirt end in the direction
perpendicular to piston pin.
“a”: 15 mm (0.59 in.)
6A1-52
ENGINE MECHANICAL
SH410
Standard
71.970 – 71.990 mm
(2.8335 – 2.8343 in.)
Piston
diameter
Oversize:
0.25 mm
(0.0098 in.)
72.220 – 72.230 mm
(2.8433 – 2.8437 in.)
0.50 mm
(0.0196 in.)
72.470 – 72.480 mm
(2.8531 – 2.8535 in.)
