G'day folks,
That Permatex 29132 looks to be the ideal silicone sealer for this job. Very similar to crankcase joint sealers that some motorcycle manufacturers [Yamaha and Honda, that I know of] have offered for that exact application, for a long time now.
FYI Alan, there are several very useful sections of the Workshop/Repair Manuals [pdf format] for the 85cc/170cc engines available as free downloads to ODK subscribers; see
https://www.outdoorking-forum.com.au/forum/u...ne-parts-list-and-manuals.html#Post54967 The new piston should have ring locating pegs in the ring grooves, on the exhaust side of the piston. These determine which way up the rings are fitted, as well as the gap position.
