I dropped a motor in my cutdog a few weeks back and haven't been able to get to hit right, and its backfiring like a 12 gauge after I hit it and let off. The cam had been advanced, and i didn't line it up out of curiousity to see how it would run. I know people have done this before, but what are you supposed to do to the timing, or plugs, or anything else to get it running right?