I tried a mousse can muffler on mine and it only got me the rpm's of the engine without a muffler. The G20's will eat it alive! I did want to inform you that the G20's have a sub-induction cylinder and sleeve which is not conductive to pipe use. It's a shame as I love those G20's!
Good luck with your engine and let us know how it runs on a pipe. I really like your thread as I had two Deceptions and loved them.
Frank