I have a Coleman 5000 Powermate generator that has a very loud exhaust. I used to use it in a rural setting,now I brought it to town.Has anyone figured out a better muffler to quiet down one of these things? It is about 5 yrs old and has a B&S 10 hp "L" head engine and the extended run fuel tank that covers to top of the cage around the engine. The exhaust outlet on the engine appears to be 3/4 pipe. Thanks