I’ve got a 01 raptor 660. Pulled it off truck let it set a minute, checked the oil and was right at min, so added almost a qt To get it right. Started kinda hard and only wanted to run with choke halfway on, ran it for a while stalled it. Checked the oil afterwards and was like almost half inch over the max. Now no start just turns over and back fires. Dropped oil, changed plug and same thing. Any ideas what to do next?