have not ran it yet. had problems starting it last fall, so it ended up sitting. the stock muffler was shot also. if it sounds anything like my race quad did, it will be a quiet mellow tone to it (its considered a high flow muffler). my guess, the sound will be about 1/4 to 1/3 throttle on a sport quad with the stock pipe. these mufflers are about 90-93 dB at 1/2 to 3/4 throttle on a quad.