danieljm-RCU, I have a GP42 on a very heavy Tiger Sport, and it flys great with it, no problems with power, mine blows oil all over the place though, but its getting wore out, I took the baffle out of the muffler too, this gave it an extra kick. I have had it on 2 diffrent airplanes. I would agree Chinooker too, I would go with one you can use in you second plane, the Pro 46 is an awsome engine at a great price, I have 2 of them and never had any serious problems with them. I will say if you cant get a 46, go with the GP42, great engine.