Small Engines (Lawn Mowers, etc.): Tecumseh 6.75, several issues, oil leaks, head gasket

Question
I have a Sears lawn mower with a 6.75 hp Tecumseh engine.  Self adjusting for the most part.  I sheared several keys because I am hard on my mower (I use the de-thatching blades and I have actually hooked up a metal rake to it as well).  I have dissassembled the carb to clean it several times thinking that may be the cause to my current problems, but to no avail.  Here's what it is doing 1) will not start or run with the air filter on. 2) oil leaks from the governer lever while running 3) produces white smoke from the air intake while running without an air filter 4) any gas left in the tank after use, leaks out through the air intake between uses.  I've never witnessed this, but it is easy to identify the remnants of the puddle the gas made when I go to use the mower again.

I'm thinking head gasket, but would love any guidance you could offer.  I can't take the dirty looks I get from my neighbors as I pollute the atmosphere.

Thanks,

Mike  

Answer
The problem is in the carb.  The inlet needle/seat is not sealing allowing gas to drain out of the carb.  Some of this gas is getting in the oil thinning it causing the oil/gas to burn causing the white smoke and the leak.  Check the engine oil...it probably smells like gas and is really thin.

You will need to drain and refill the oil, clean the carb while checking the float to make sure it does not have a hole in it, replace the carb inlet needle and seat, remove, clean and dry the muffler to get the oil/gas out of it to cure the smoking.

I doubt the head gasket has anything to do with your problems.

Let me know if this make sense.
Eric