Thanks for all the input! I think you may have got the 2.3/16 . the saw does have a 16in bar. I have some pics of cases and the s.s. mod. for when I sent them to the comp. in maryland for Id . So 2.3 would be 38cc? I got the new mod yesterday, bolted er up and used a matchbook cover to gap to the flywheel. And just turning the flywheel by hand Ive got good spark! I cant show block pics today, a machinist buddy is trimming of the oil tank and excess stuff around the basic case. When I get it back Ill get some pics of it. Flyjoe, theTF47 is a top flite P47 kit I built. I have a ys120 4stroke in it now. Heres a couple pics. It weighs about 9lbs. If this saw engine is a 38cc it would be to much dont you think? My plan was to put this engine in the Geebee then find a 45cc or up for the Bryons Eagle. Heres what they look like.