Brass in K341

My neighbor has a Kohler K341 - 16 hp about like the one on my Wheel Horse and recently some brass filings have shown up in his oil. He was asking me about it and I can't place where brass would come from.

There is a brass bushing on the governor shaft, I believe. Anything on the crankshaft should be aluminum.

Any Kohler K series pros out there with a possibility?

Brass in K341