Piston Pin Bushing; Assembling Piston And Connecting Rod - Yanmar 3YM30 Sevice Manual

5.4.3 Piston pin bushing

(1) Measuring piston pin clearance.
Excessive piston pin bushing wear may result in
damage to the piston pin or the piston itself.
Measure the piston pin bushing inside diameter and
the piston pin outside diameter. Calculate the oil
clearance from the measured values. (Refer to 5.3.2
for the piston pin.)
Piston pin metal
22.025-22.038
I.D.
Pin O.D. 21.991-22.000
Clearance 0.025-0.047
NOTE:
Since the rod small end is tapered, bush insertion is
extremely difficult. Any minor mistake will cause
abnormalities such as twist and bite. Do not insert the
bush on-site.
(No piston pin bush spare part is available. It is
included in the connecting rod assembly supplied as
a spare part.)
5.4.4 Assembling piston and connecting
rod
The piston and connecting rod should be assembled so
that the match mark on the connecting rod large en
faced the fuel injection pump side and the combustion
chamber above the piston is close to the fuel injection
pump.
Standard Limit
22.068
21.963
0.105
5. Inspection and servicing of basic engine parts
mm
Cylinder gage
(Connecting rod small end)
Piston ID mark
Cylinder size mark
(Flywheel side)
Piston ID mark
(
Assembly direction of connecting
rod and piston
124
Embossed mark
(Flywheel side)
Match mark
)