I agree about the Rossi .81, good strong motor. It has slightly less power than the OS .91 (I had both on a test stand at the same time and there is around 1000 rpm difference in the two) The parts are hard to come by, and the carb. is a nightmare to tune. I had a buddy tune it for me (he had about ten of them over a lifetime) and it worked great, until the next day. Every day I flew it I spent the first hour setting the needle. Really got old after a while. The comment about gluing the carb is only funny because I have been there. Thought about welding it one day. HA!

Just asking (don't take any offense) but why are you interrested in the Rossi .81 when there are tons of used (and new) OS .91's out there looking for a good home? I really think you would be better off with the OS in the long run. Feel free to PM me if you need any further info.. Good luck!