the Sportsman 500 2000, came in with a no running problem, found stator no production of voltage, took cover off and hand start mechanism had fallen apart and was shrouded and broken the plastic and metal in 100 pieces and tore up the stator assembly. I replaced it with a new assembly also it had been sitting for a long time so I cleaned the carburetor and gas tank and the fuel pump was corroded so I replaced the fuel pump too. It started really good and ran pretty good. But in the mean time I rode it and I came to a stop sign and it backed fired and from then on it has not run worth a dam. I rechecked just about every component and I even replace coil, cdi box, and regulator and still the same problem and I overhauled the carburetor and re calibrated with different size of jet.s It idles fair and when you accelerate it dies, acts like you ran out of gas. And dies also when you de-acelrate to idle at times. If anyone has an IDEA I would really appreciate the Help because this is driving me crazy!