What method are you using for break in? The heat cycle method works the best IMO. To do this, you fire up the engine and let it warm up, once it's warm you drive it around at 1/4 - 1/2 throttle (give it a little more throttle with every tank, but start at 1/4 max on tank one). Make sure it always runs pig rich!! Once it's up to operating temps 220-260 and the tank has run out shut it down and let it cool all of the way back down. Make sure to put your piston at BDC(bottom dead center) after you shut the engine down. After about 5-6 tanks it should be pretty freed up and ready to go. I would baby it just a little bit though, until you've got 3/4 gallon through it or more. By this I mean no WOT runs down the street or anything. Try and only occasionally bump WOT.