My neighbor flipped his lawn vacuum cart over while it was running and the engine, a briggs flat head, started smoking heavily. Now he says it will not start so I'm guessing oil was pulled into the carb and exhaust. Anyone have experience with how to go about a remedy? I'm thinking pull the carb and clean, pull the head and make sure top combustion chamber is free of excessive oil and then perform a drain/refill with fresh oil. Probably a new plug too.