Small Engines (Lawn Mowers, etc.): engine consuming oil, craftsman riding mower, dipstick tube

Question
I own a 2004 Craftsman riding mower with a Intek single cylinder engine.Model#31p777 type 0348e1.Last fall I noticed some smoke coming out of the exhaust upon engaging the blades.I found the oil level down on the stick.I topped it off last fall and today after mowing it was down almost off the stick after mowing 2 or 3 times.Heard of any bad history with these engines? I have changed oil and filter every year since it was new.Could it be the valve seals or the piston rings? Any advise would be much appreciated.

Answer
It could be any of the above that you stated.  It could also be as simple as a stuck valve breather or a leaking dipstick tube o-ring.

Since the engine is not that old I would not suspect the rings.  Are you using SAE-30 weight oil?  Does the oil smell like gasoline?

Let me know.
Eric