Small Engines (Lawn Mowers, etc.): oil fowling spark plug, head gasket repair, blown head gasket

Question
Paul, I just purchased a second hand Craftsman 16HP lawn tractor (42") , model 917.270670, B&S engine, 5 years old.  Has started fine from cold start, but will not restart easily once hot.  Pulled plug and found it covered in oil.  Cleaned plug and engine started with hefty white smoke blowout. No other obvious symptoms, but frustrating to not be able to stop and restart when I choose.  Any suggestions on correcting this problem?  J

Answer
Have you changed the oil lately?  sounds like the old "poured in two quarts and now it smokes and fouls plug" syndrome.

Drain the oil and fill with 48oz and see what happens.

If the current oil level is correct you have a blown head gasket.  Repair level 3 on a 1-10 scale.