I am running a Precision Eagle 4.2 on a 30% Carden Extra 300, It was running great last summer, then it was put away for the winter and taken back out for spring. The first flight in spring it was running good for about 5 minutes then the engine started acting very strange.after that it would backfire and start back wards and all kinds of stuff. So I figured it was the ignition so I sent back the ignition for repair at C&H Electronics and they said it was working fine, they even tested it and everything. So we got it back and the engine starts but on full throttle I'm getting about 3500 RPM's when I usually get about 6100 RPM's and the engine sounds really rich. But it isn't. I'm thinking that the timing is messed up on the engine. And on this engine I don't know how to regulate the timing. If anyone is familiar with this engine plz help me. Thanks