Small Engines (Lawn Mowers, etc.): Lawn Mower, full throtle, crankcase

Question
When I started my briggs and straton lawn mower this morning it emitted this thick white smoke which eventually stopped but it didn't sound like it was running at full throtle either. Can you help me out?

Answer
Hello Josh:

STOP!!!  Check the Crankcase for Oil and Gas Mixing and for an Overfilled Crankcase. Change the Oil. If the Engine Runs Proper, then Install a Manual Cut Off Valve in the Gas Line Between the Carburetor and Gas Tank. Turn Of the Gas to the Engine When the Mower is Not In Use. You will have to Install a New Needle and Seat in the Carburetor if the Engine is Not Operating Properly. This is a Common Problem and a New Needle and Seat Correct the Problem Only Temperarly. Usually the Problem will Return in a Few Months. The Manual Cut Off Valve is the Only Way I Have Found to Prevent the Oil and Gas in the Crankcase Problem. Hope this Helps. I am Here if You Require More Assistance. Let Me Know What Happens, Please. Thanks.

Good Luck

Respectfully  

John