Small Engines (Lawn Mowers, etc.): 16.5 Briggs OHC blowing oil under load, mosquito fogger, head gasket

Question
30 weight oil changed this season (each season). Only tune up has been to clean or replace the plug and air filter as needed.

Other inquiries on the site indicate head gasket so I pulled the head and it does appear to have been leaking from the cylinder back through to the crankcase. Picked up a gasket today, will be replacing this weekend.
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Followup To

Question -
I have a 2000 MTD rider with a 16.5 Briggs OHC I/C engine. It has suddenly stared smoking under a cutting load. I removed the air filter and observed that a trickle of motor oil is pouring into the carb air intake while running at full throttle. When the deck is engaged the oil flow increases. When I move into grass the oil begins pouring in and the mower smokes like a mosquito fogger. Where should I begin looking for the cause of this?

Answer -
What oil weight are you using?
When was the last oil change?
When was the last major engine tune-up?

Let me know.
Eric

Answer
Let me know if the head gasket fixes the problem.  Do you know what to set the valve gap to?

I would also recommed taking the time to clean the valve breather.  You can locate the breather by following the tube from the air cleaner housing.

Just clean with some Brake Clean, carb cleaner or gas.  Blow dry the breather with compressed air.  When you are done the breather should rattle like a baby rattle toy when you shake it.

Let me know if the head gasket fixes the problem.
Eric