I have 2 Homelite engines I am in the process of converting. I thought they were both 30cc, but I am seeing some diferences. One engine has a single ring piston with the little exhaust port on the cylinder. The other engine has a slightly bigger diameter piston, no exhaust port and is double ringed. Other than those differences they appear to be identical. Any ideas ?

The smaller of the 2 has been run with a scratch built muffler and is turning an 18x6 prop at 7400, the other one has not yet been run.

Thanks in advance
Scott

I think some pics would help. Sounds like one may be a "new and improved" version of the other.

Adam

Most of the 25cc have one ring and the divided exhaust. The 30cc have two rings and an open exhaust