I added oil to my Briggs Stratton and realized I put 5W-30 in. Having said that, when I started it, smoke was coming out of it profusely. Since, I drained the oil and replaced it with SAE30. It still is not running correctly and smoke still comes out and doesn;t seem to be able to get up to speed. Any thoughts?

Chris McKay, April 2006

5W-30 oil wouldn't have done any damage. But you DO want to run the SAE30.
When you changed the oil did you have the mower turned on it's side? When the engine is tipped to the side oil gets into the cylinder and usually ends up in the muffler. Replace the spark plug. It's probabaly oil fouled. Then start it up and let it smoke. It will burn the oil out of the muffler in a few minutes then it will stop smoking.

Rick, May 2006