I want to quiet my Rotax 912A (80 hp). My exhaust system has been modified as there is no room inside the cowl for a Rotax muffler. Each side of my exhaust is connected so I have 2 header pipes exiting the bottom rear of the cowl next to each other just left of center [pilot side], one header from each side of the engine. I've tried a pair of custom mufflers and am not happy with the results (still way too loud) and I would like to go to a single muffler.

Any advise for "under the belly" type muffler solutions would be appreciated.