Baffles get gummed up with carbon. Carefully undo the bolt and use mole grips or a wire coat hanger to remove the baffle. If it wont come out, you will need to remove the silencer and bang the back end onto a block of wood to loosen the baffle. Once out , clean baffle with a wire brush in a drill or hand. If it is rotted, do some accurate measuring , post on here and I'll make you a new one. Do you have pix of a drawing of front end of silencer and header pipe to engine? Found this on eBay http://www.ebay.co.uk/itm/BRAND-NEW-KYM ... 4ab925c541 Doesn't look like the baffle is removable ???