Arniebarn;

I am still using the flywheel on the conversions, albeit they were lathed down. 700 rpms and 4 - 12 pounds thrust DROP when using Zinger vs APC or MA.. Just can't figure. Maybe lower in compression and they benefit with added weight and centrifical motion on the shaft. I was just curious if anyone else found this to be true or had the answer. Could be just one of those things..... some engines prefer some props.