Imcub and Jaka.
i have the alpha and we had the same problem. this is what we did ... (1) had two change the fuel line from the tank to the needle valve, and from there to carb. both had pin holes in them. (2) had to change fuel, i'm running proformance plus 15%. haven't had to mess with any needle settings since.. love this plane and motor. oh yeah throw the 3 blade away. running 11x6 just great.... spooner