RE: rossi 46 problems
Listen to johnbuckner's advice, Rossi's are a different animal and will not run without a head shim above 5% nitro. Save yourself alot of grief and buy some FAI fuel. I'm running 0% in my 46 and it runs as advertised. I too tried at first to operate this like a typical glow engine at first and could not get it to transition well. Before you accept any advice make sure that they have actually tuned a Rossi and had it run well. Good luck and enjoy!
Jim