I Was recently using my tractor to clear snow when i noticed that it seemed slugish and was lacking power. I later discovered that gas was in my oil. I changed the oil and the tractor sounded like the power had been fully restored. After a few minutes the same thing happened again. How is the gas getting into the oil? Could it be a stuck carb float or piston rings? Thanks

If the tractor is running "rough" and there is black smoke coming from the exhaust, then it is getting too much gas. It could be a stuck float, carb adjustment, or junk in the float bowl/passageways.