Anybody have any experience with these engines. I just bought an Extra 300 with this motor on the plane. The guy started before I bought it and he was running that premixed super fuel. I already run 40:1 supreme pump gas in my son's DLE 111 and don't wanna pay the price for that super fuel. Went out today to start it for the first time after I got everything set up. All it does is spit, sputter, backfire, sometimes starts backwards. When it does start it runs for a short time, backfires and quits. Played with need valve some. It was close to 3 turns out. I have the manual , and I rest it back to factory settings at 1 3/4 turns. No change at all. Any help or advise would be appreciated.

This line of engines has a troubling past. The primary issues we found were the pistons were undersized for the cylinder bore which caused premature wear due to piston slap (rocking in the bore) and no piston ring would solve that issue.
A properly sized piston to the bore would solve that particular issue.
I would make sure your bases are covered, clean carb, proper timing, reeds, etc.

Hi Kevin, sent you a PM.