Without even looking at it I am almost certain that it is a missaligned cylinder and engine body as the more I think about it I think that the holes in the cylinder are about .010" off or so. I need to take the inlet hose off and look through and see how the holes line up when the piston it at the bottom of the power stroke but if it is blocking the inlet before the piston is down I would think that would make it stop like it is. Dang even though I am mad at it I can't seem to stop trying to figure out what is wrong with it.