The bike was surprisingly loud the first time I started it. I removed the baffle and discovered there was just a small thin piece of fiberglass packing around it. I rewrapped the baffle with thicker packing. This brought the sounds down a bit, but I thought it was still too loud.
I added a homemade restricter to the baffle. It’s helped bring down the volume a bit more. The change was not dramatic. I’m going to try adding more washers, perhaps alternating the 1 1/2″ drilled washers with 1 1/4″ undrilled ones. The stepped bracket helps keep the restricter centered without drilling additional holes in the baffle.