Originally Posted by
JustEnough
There is a lot of room at the end of the DG pipe to put a muffler core in. I called DG to see if they offered a muffler core and the guy just laughed at me. I took a 8" length of electrical conduit and drilled a bunch of 1/8" holes in it and then pinched the end closed on the engine side. I MIG welded the conduit to a flange that was like a giant washer. It was about as quiet as a stock muffler and did not seem to have too muck back pressure. The MIG weld did not hold so I plan to braze the conduit to the flange so that it will hold up to the vibration. I also plan to braze a stainless steel screen like a sock over the drilled conduit to make it a spark arrestor.
I think the stock DG "muffler" is just a fiberglass lined straight pipe and sounds like a loud Harley.