Rich if you get a chance try it wih a Xoar prop. The rpm seems a little low. I don't know if it is the engine or that prop loads the engine allot. I have an SPE which uses the same cylinder, piston, etc. basicly just has a different crankcase from what I can tell. I have it changed to Rcexl ignition set at 28 degrees. On the first tank it was turning a Xoar 16x8 at 8300.