Small Engines (Lawn Mowers, etc.): Kohler oil consumption, breather element, oil consumption

Question
My father have a CV15 OHV  Kohler verticle shaft engine in a toro lawn tractor  eight years old with normal maintence  it just started using oil BIG time  looks like oil is coming out of muffler  not a whole lot of smoke but will go thru a quart in a couple of hours of mowing  any ideas ?

Answer
Check to see if the breather element or tube is blocked going to the carburetor. I'm not sure why it is passing that much oil into the muffler and not smoking a great deal. Almost makes me want to think it is leaking externally and then down onto the muffler. I would first totally degrease the engine, then making sure it is full of oil, run it and check everywhere for an external leak leaking onto the muffler. For it to smoke so little and pass that much oil past the rings is highly unlikely. Does this model have a oil cooler, they leak often, especially the ones that are mounted between the. block and oil filter. Also if you find no leaks I'd run a compression test to check the integrity of the rings, compression should be around 140-150-psi...Tom