I was wondering if anyone could help me out with some engine troubles that I have been having. I recently completed my first build (Kadet LT 40) and I put a .40 FX engine on this airplane. The engine develops good power, but the problems occur at mid to low throttle. WHen I advance the throttle, the engine really loads up, and behaves as if it is a full turn on the needle valve too rich. Full throttle is okay, after it leans out, and when I return to a lower throttle setting, the engine runs superbly, untill landing. THe engine has a disturbing tendency to quit. I think only 2 or 3 flights have seen the engine runnign after landing.

I think the fuel tank is in the right place, it is where it is placed as per sig's directions. I do have a "t" for filling the fuel tank and a filter between the engine and the fuel tank, though.

I do not have any experience on how to tune an aircraft engine for proper operation, please give me any help you can.