I finally got the FS80 put together and on the test stand. I put a set of Bowman rings in and cleaned it up. Mixed up a batch of gas oil about 40 to 1 and put a 16x6 MAS prop. I got 8100 RPM on it which I thought was ok but it still lacks compression. Maybe the rings will take awhile to seat with the Chrome cylinder??? I think I'll try a bigger 17x6 or 16x8 to 10 and see if it pulls the same-could be it just won't rev any more than that based on the porting. Lite engine with OK power though.