I understand what you are saying. But I had a Fox .35 Stunt on a Sig Banshee and never encountered problems you mentioned. Are you running any pressure from the muffler to the tank? Also I used a Uniflow tank, a Thunderbolt RC plug and 10% fuel. Something doesn't seem right. Fox .35 Stunts are not my favorite engine, but I ran enough of them to know that they are pretty dependable as long you feed them right. I'm just wondering if something in your setup is really causing your problems. When I was flying the Banshee, I could do a pretty crappy pattern, but I couldn't blame the engine, it ran just fine. That engine should not be cutting out on a horizontal eight. It's one of the easiest maneuvers you could do with it. Don't take this wrong, I don't mean to upset you, I just think something is wrong. Could you be running it too rich?