[westofb]

If you need to use it for the rest of the season, I would say keep doing what your doing...checking the oil and keeping it full. If it were mine, I would skip the constant oil changes...you are adding oil to it regularly anyhow, it is most likely getting dirty from the blow by around the piston. I would make sure to check and clean the crank case breather too. If you are worried about keeping the oil changed, change it every couple weeks or so (you said you use it around 10 hrs/ week). Once the mowing season is over, pull the engine are do a thorough rebuild on it, piston, rings, rod, governor gear, governor cross shaft, and cross shaft bushing. Once you pull it and get it apart, a good machinist can measure the cylinder bore and the crank's rod journal and specify what parts you need to order. I would also have them check the valves, valve seats, valve guides and replace whatever it needs. It should be good for several more decades of use after going through the engine.

Check out ebay for motor rebuild parts, you can get a kit using Stens parts for around $100 (if you need every component I mentioned, would run you around $150-175). From what I have read, people have good luck with them, I ordered a kit for my K321, hopefully someday the machine shop will get it done so I testify whether or not they parts are good or bad from personal experience.