Twostroker is right but one more thing you might want to try. If you have a computer radio that allows expo on the throttle try adding a little there. I use this same engine and I think I have around 30% in mine. This engine rev's its quickest after 1/2 throttle and we have to keep in mind that it wont react as fast as we can move our thumb. By slowing the throttle down a little on the lower end the engine has a little more time to react to the fuel coming in and is not as bad to lag. It wont completely solve the nature of this beast but is a lot cheaper!! What ever you decide good luck and keep us posted!!