Re: one cyl not firing
make sure floats are adjusted right my motor had one come out of adjustment all of a sudden and i was loosing 1 cyl because is was being flooded by the carb because the float was to high. Just another thought. Because i was checking everything else at fist because i knew i was getting gas in there, just did not realize that it was to much gas. New needle vavle and seat and float corrected the problem though.
-Nate