Small Engines (Lawn Mowers, etc.): briggs & stratton 6.5 hp lawn mower engine, sears craftsman, briggs stratton

Question
Eric, i have a sears craftsman self propelled lawn mower,it's approx 3yrs old.i change the oil and air filter anually.lately I've noticed a puff of smoke coming out of the muffler when the mower is first started, then stops while operating the mower.why is this happening?john

Answer
Are you using SAE-30 weight oil?  What is the mower model number, xxx.xxxxxx?

Do you have to add oil often?  Many engines, as they wear, will leak a little oil past the rings and valves in between use.  Is the smoke white?
Does the oil smell like gasoline?

If the engine is not conusming oil I would not worry too much about the smoke at start up.

Let me know the mower model number an I can look up your engine.
Eric