Since putting the new tires on my Doodle Bug, the rear tire keeps going flat on me. I can't figure out why, so am thinking about putting some tire sealant in it. Question is do you guys recommend using tire sealant on a mini bike? Valve stem is tight, nothing in the tire and the beads LOOK good. I can't figure it out. BTW, I took the Generac off because I couldn't solve the throttle issue and put the 3hp back on it. It runs great and pulls my 200 pounds around the hood fast enough. If I burn out the clutch, I'll put a new one on it.