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ENGINE TOP E ND 4-7
Stuff a clean cloth into the crankcase opening around the
connecting rod so that no parts will fall into the crankcase.
Scrape off any carbon of the piston, then lightly polish the
piston with fine emery cloth.
Clean carbon and dirt out of the piston ring groove using
a suitable tool.
Carbon particles can be very abrasive to piston
ring. Don’t allow such particles to fall onto the
When installing the piston ring on the piston, note the fol-
First fit one end of the piston ring against the pin i n the
ring groove, spread the ring opening with the other hand
and then slip the ring into the groove.
The top ring have a “1N” mark [A] on its upper surface.
The second ring have a “2N” mark [B] on its upper surface.
Install the ring so that the pin [A] in the piston ring groove
is between the ends of the piston ring.
Apply 2-stroke engine oil to the connecting rod needle
bearing and the piston pin.
Install the piston [A] so that the “IN” marked side [B] faces
the back (intake) side of the engine.
When installing a piston pin snap ring [A], compress it only
enough to install it and no more.
Do not reuse snap rings, as removal weakens and
deforms them. They could fall out and score the
Fit a new piston pin snap ring into the side of the piston so
that the ring opening [B] does not coincide with the notch
[C] in the edge of the piston pin hole.