My father in law has a Hustler Mini Z with the Kawasaki motor. Yesterday while mowing the engine started smoking and making a horrible banging noise. I shut the mower down and upon checking the engine oil discovered it very low, and very nasty. I replaced the engine oil and put on a new oil filter and it ran fine after that. That is until today. I mowed around the property for about an hour today and then noticed a burning smell. I shut down the blades and looked at the engine and it was smoking a little. The oil filter was extremely hot and when it took the dipstick out of the oil reservoir smoke came from inside. I let it sit for an hour and went back to try it again. This time the motor is locked up! All it does is make a single "clank" when trying to start. I have no idea what to do now. Any help is much appreciated.