Hey guys! It's Old Reliable back from a long break from this site. Took a break from from the morini bc parts are expensive and hard to come by. I purchased a new 66cc slant head ht engine about 2 months ago. I ran 50:1 for the first gallon and now 32:1 for nominal use. My engine was running great yesterday, but blew out my exhaust gasket. I replaced the gasket with an aluminum gasket, and the engine bogs at WOT and vibrates a **** load. I took off the exhaust and that still happens. My spark plug is a dark red. Any help here?