PISTONS AND PISTON RINGS
The pistons are made of an aluminum alloy. The
piston pins are made of steel and are a precision fit.
The piston pin is held in place by a clip at each end.
Refer to
Figure 108
when servicing the piston
and rings.
Piston Removal
1. Remove the cylinder head and cylinder as de-
scribed in this chapter.
2. Lightly mark the top of the piston (front or rear)
so it can be installed in the correct cylinder during
installation.
WARNING
The edges of all piston rings are very
sharp. Be careful when handling them
to avoid cutting fingers.
3. Before removing the piston, hold the connecting
rod tightly and rock the piston (
Figure 117
). 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
(more likely a combination of these). If necessary,
replace the piston and piston pin as a set.
NOTE
Wrap a clean shop cloth under the
piston so the piston pin clip will not
fall into the crankcase.
4. Remove a circlip (
Figure 118
) from one side of
the piston pin bore with a small screwdriver or
scribe. Hold your thumb over one edge of the clip
when removing it to prevent the clip from springing
out. Deburr the piston pin and the circlip groove as
necessary.
NOTE
Discard the piston pin circlip. New
circlips must be installed during as
sembly.
5. From the other side, push the piston pin out of
the piston by hand. If the pin is tight, remove it with
ENGINE TOP END
123
4
114
115
116
117