Ok, I have a lil ole 2-stroke, and I just bought a new wiseco piston for it, well, it didn't fit too good, so someone gave me the suggestion of sanding down the rings, so I did that, and I finally got it in, but the clearances are so tight that it doesn't spin over enough to start the engine firing. What should I do? File the rings more? It ran before I put in the piston, and that is the only change.