Basically I don't know exactly what I am doing. An old roommate left a 1990 Banshee that didn't run at my house. The problem was electrical, so by process of elimination I found and corrected the problem. Every thing electrical is now new effectively, then I cleaned and rebuilt the carbs because it still wouldn't start. When I put the carbs back in it fired a couple times, then finally started. I gave it a little gas, the let off the throttle and it quit. I got it to start once more after that, then again let off the throttle and it quit. Now, all I get is a little backfire when I'm kicking it and some smoke comes out of it. I know very little about 2 stroke engines and any advice would be appreciated. Thanks.