I was having trouble getting a spark to my ATV. I replaced the Pickup Coil, Stator, and Rectifier. After that I started to get spark, but it is not running right. It will start on full choke with the throttle all the way in, but will not rev up. It acts like it wants to at times. If you let off the throttle, it will idle, but as soon as you hit the gas it will backfire out of the air box and die. I have checked the carb and it seems clean..Thoughts?