Yep, that was the problem. No popping, runs good. Gosh Dang! This thing runs good!!! My whole street sounds like we are at a dragstrip when the thing is idleing! The only thing I think I need to do now is tune the carburator and maybe timing. The motor doesn't like a lot of throttle yet. That might be cuz I have a 50cc accelerator pump on the primaries. Probably go back to a 30cc and see how it runs. A lot of throttle response though!! Revs like a 327 and sounds like a monster!!