Re: Engine Problem
I use opti also but 100 to 1 was letting my motor run too hot. You might try 75 to 1. My new top end has run on 75 to 1 since day one and I have great compression. How much viberation are you getting? The jet in the carb sometimes loosens up. You can also have fuel foaming. But I think you have a vacuum leak. Try short shots of wd-40 around the intake, carb mount, cylinder base, also check the head bolts. If you hit a leak the motor will slow for a moment. The WD temp. plugs the leak. If the motor races then it's almost for sure vacuum. Esp check the cylinder base. The motor gets hot the head bolts expand and a leak that wasn't there before suddenly is. Good Luck
Put something FUN between your legs..