RE: A home for my Rossi 53
Also to add to Yukonflyr-
I have both the 45 and the 53, and the 53 seems to be a bored out 45. Both needle easily and run very well, with a nice midrange. I must say the learning curve to reach this ease of operation was steep though!
Possible causes of fussiness: Compression too low causing narrow/sensitive needle range (up the Nitro a little, put in a hotter plug- Rossi No. 3 or 4, or decrease the head clearance), propeller too big, I'd suggest 16000+ RPM on the ground- I've found a Bolly Clubman 9.5x6 to work well. Or tuned pipe length too short or too long if that's what you are using.
Good luck!
P