Piston Pin Remova/Installation (Multicylinder); Piston/Cylinder (Multicylinder) - Yanmar 1GM10 Shop Manual

Piston Pin RemovaUInstallation
The steel piston pin rides directly in the piston and in a
bushing in the connecting rod. Circlips at each end retain
the piston pin in the piston.
1. Before removing the piston, place the crankshaft end
of the connecting rod in a vise with soft jaws. Rock the
piston as shown in Figure 29. Any rocking motion (do not
confuse with the normal sliding motion) indicates wear on
the piston pin, piston pin bore or connecting rod small end
bore (or combination of these).
2. Remove the clip from each side of the piston pin bore
(Figure 30) with a small screwdriver or scribe. Hold a
thumb over one edge of the clip when removing it to pre-
vent the clip from springing out.
3. Use a wooden dowel or suitable tool and push out the
piston pin. If the pin is difficult to remove, heat the piston
with a hair dryer. Separate the piston from the connecting
rod.
Unless precision measuring equipment is available,
have this procedure done by a machine shop.
1. Measure the piston diameter with a micrometer (Fig-
ure 31) at a right angle to the piston pin bore 9 mm (0.35
in.) from the bottom of the piston skirt.
CHAPTER SIX
Bolts