In that Aussie ? reveiw the SR pictured had an English Tri-BSA looking muffler on it. When I bought my beat to hell SR 500 it had no muffler . I had a Triumph style muffler that had an adapter welded to it to allow it to fit on a 860 Ducati I bought. So I slipped it on the SR and went for a test ride. It was fairly quiet , but, choked the motor down badly. I went with a Supertrapp and it was loud and made the motor happy again. If it comes and our opinion matters , I vote for the 500 cc size. The U.S. is not Japan.