Small Engines (Lawn Mowers, etc.): 17 hp briggs white smoke from exaust oil in air cleaner, craftsman lt1000, briggs and stratton

Question
picked up a used craftsman lt1000 17hp briggs and stratton just trying to figure why after a few minutes of running huge clouds of white smoke coming out of exaust,although it seems to run fine. it does bog down in the highest throttle position. i gotta fix this tractor any advice would be appreciated

Answer
Does the gas smell like oil?  Have you changed the oil?  Did you clean the valve breather?  Is the dipstick tube top and bottom o-rings sealing?

The carb may have leaked due to being dirty and thinned the oil.  The gas/oil mix may be causing the smoking, even residual oil in the muffler can take a while to burn out.

Does the engine use oil?  Do you have to add oil everytime you use the mower?

Let me know.
Eric