Why will it run like crap once its warmed up? I have a freshly cleaned carb new plug, new rings a few weeks ago. Its a klt 200c1. Could the tailpipe be boiling the gas in the carburetor? The exhaust runs right underneath the carb and the heat shields only about 1/8th inch away from the carb. Oh and the mufflers gutted. (freaking thanks dad now i cant ride late at night)