Motor will fire and run but will not stay running for more than a few seconds, and when it does run we are pretty sure it wants to idle out of control for a little bit. Also, after it dies and we try to restart it there is a pretty major backfire issue that we can feel pushing back on the kickstart. When it does fire, it fires quite readily with minor input to the kickstart. This bike was a barnfind so we are starting from scratch. Carb was cleaned and rebuilt and we were using new, clean fuel and fuel lines. Any help would be appreciated