i've had the same problems with the break in of my sirio .12, i cant get fuel to the carb. the problem comes from that high end needle housing where the fuel comes in to. when its tight, fuel cant get to the carb. when i loosen it just a tad, fuel goes to the engine, but leaks out all over through the spaces in the inlet. I havn't been able to get it started yet. I'll have to dig into this some more. have any of you experienced the same problem? if so, how'd you take care of it short of putting in a different carb?