Bill, thanks for the rapid reply. Well, I'm not much into wild......yet.......so perhaps I'll put something else on.....I have a Towers gift cert thats burning a hole in my pocket so perhaps I'll spring for an OS 50 SX. I think this might be a superb engine for this plane. I had another Four Star months ago.......RIP.......and it also had a .46 AX in it. You're right, it did great. I have one .50 SX that I've used in other 40 sized planes and it really is a nice setup