Section 4 Disassembly and service
Timing gear
Disassembly:
1. scribe a line on the crankshaft and the timing
gear tooth as shown.
2. use a hydraulic press and a commercially
available bearing puller to remove the timing gear.
Reassembly:
1. using the old gear for reference, scribe a line at
the same position on the new timing gear tooth.
2. use a hydraulic press and the special tool to
press the timing gear in with the scribed marks
aligned.
Notice
Do not scribe the crankshaft deeply. Otherwise,
oil may seep through the oil seal.
Inspection
Piston pin OD
Model
Standard
Service limit
G250F(D)S
18.0 mm
17.954 mm
Cylinder inside diameter
Measure three points on the “X” and “Y” shaft
and record cylinder inside diameter
（
“X” shaft is vertical
to crankshaft and “Y” shaft parallel to crankshaft
）
.
Take maximum reading as the wearing and tapering of
the cylinder.
Model
Standard
Service limit
G250F(D)S
75.0 mm
75.17 mm
Piston skirt outside diameter
Measure and record the piston skirt outside diameter
at the 10mm from piston skirt maximum lower side
making 90°to piston pin hole.
Model
Standard
Service limit
G250F(D)S
74.97 mm
74.82 mm
4-27
