I had the same problem as Bill, it would only kinda run with the starter down. I had fuel, spark, and compression. I then just started messing around and found out I didnt have enough fuel. When I pulled the valve out of the bottom of the tank, the gas didn't come out to fast. I then proceeded to push a piece of wire up into the tank. I was covered in gas, but then it ran good. So check if you have enough fuel. Thats what I say. The best of Luck!