I replaced my deck belt and a couple deck idlers about 3 hours run time ago. Started mowing today and smelled a funny smell, thought a belt but checked them both and seemed fine. Ran normal and cut grass for 1 hour with no problems. Pulling into the garage I found this half of a plastic disk that was burned in half and some clumps of melted plastic. I know it is from the X300. No idea of where it came from? It is about 3.5 inches in diameter and a lip around the inside edge. Anyone have an idea of where from or what it is?