Went to change the oil and saw grey silt in the oil. Assuming it's aluminum. Changed oil and filter several times. Still there. I did find a 1/4" steel ball in the air filter. Don't know if that's related or not. Engine seems to run fine. Ran fine last year. Did seem to get hot once. Appreciate the help.

2003 23hp Kohler.
Any known failures? Getting ready to pull it to take a look at what is wearing. Question is why?