JD, I'm nearing completeion (except for paint) and had planned to leave the muffler stock. I just read the stamping on thye muffler & there is no mention of a spark arrestor. With the cat intact, I feel it's safe, but I don't believe it'll be legal on the trails. I have been checked a couple of times on my KTM.
Seabee1 "Cute like baby rabbits"