Might be worth your while to pull the carb off, and do a cheap rebuild..Or maybe just a good clean up and adjustments..I know you are very knowledgeable, but I know that a messed up carb will dump gas into the cylinders..Just a Sunday morning thought, but how about pulling all the plugs and cranking it for awhile to clean out the cylinders..Clean and gap the plugs, and give it another try..Good Luck, Steve
