Small Engines (Lawn Mowers, etc.): Murray B&S 11HP 30 Riding Lawnmower, briggs stratton engine, briggs stratton

Question
My three year old mower has an 11HP Briggs & Stratton engine.  Last winter (I live outside Houston so we mow year round) I started the engine after it had been sitting for about three weeks and it started blowing white smoke and spewing liquid out of the muffler.  I found that the entire gas tank had drained into the oil reservoir.  I thought it was a fluke but after I changed oil it happened again.  I installed a fuel line valve and I now cut off the gas after I finish mowing.  This has worked great for six months but last weekend after mowing the whole yard it started burning oil and fogging the entire neighborhood.  I got it to the garage and the oil looked OK.  I've changed the oil again and I ran it today (just a short test run) and it seems fine (again).  WAAAASSSSUUUUPPPPP?

Thanks in advance!!!!!!!!  

Answer
Hi Clyde,

It seems like you solved the fuel problem which sounds like a leaking float needle valve.  The burning oil being a one time thing IS very strange.  A problem may be starting, where oil is getting into the combustion chamber.  Rings, valve guides or an over pressurized crankcase.  If it happens again, check the crankcase vent or do a compression test.  Other than that, I'm baffled.

Let me know how you make out.
Michael