There is smoke coming from the air intake on my B&S twin cooled ohv tractor engine it started happening when i put the mower deck and it put a ' load' on the engine i checked the spark plug and that is fine i havent actualy ran the engine sence i saw the smoke but even after i let it sit for a few minutes then turn it over by hand and smoke still comes out of the carberator/air intske and anothervting is the muffler get realy hot fast with in a minute ir to of runing the engine the muffler gets to hot to touch then after driving for about 20 minutes without the mower deck on the engine over heats and shuts off ( atleast i think it over heats )