I broke one in last week and it was the same thing. Had to lean it out just to keep it running. Now that it has some tanks through it it runs very strong. Break in was kind of a pain. Just hang in there. 220 sounds good for break in but from what I read and past Thunder tiger engines that I have had they like to run better on the hotter side. 260-270 it runs very strong. They have an extremly tight pinch from the factory and dont really wake up till about 1 gallon. If temps are good and you have good smoke then dont worry about anything else as long as it runs good.