exhaust

I have been running a stock exhaust and muffler for years. I can't help but think that the stock muffler is very restrictive. Does anyone have any suggestions as to something better, that makes more power? My motor is stock.
Paul

get a hole saw the same size as the outlet and a real long extension and drill through the baffle inside. Or cut one end off in a band saw pull out all the remaing stuffing reweld the end back on and away u go