I would try running the engine as is at the field. See if someone complains. You might not have to do a thing. Remember, you can't judge how loud your model is if you are running it over your driveway at home. That makes everything sound much louder than how it will sound at the field.

I used to fly my CGM Cub powered with an Enya 80-4C four-stroke engine without a muffler because it didn't come with one. Just a plain old header pipe with no means of attaching a muffler. No one said a word about it, so I asked one day if anyone thought that the engine was too loud. The Cub was airborne when I asked the question. Everyone said to keep it like it is, that it was pleasant to listen too. Later issues of this engine did come with a muffler, but I never did pay the $60 that MRC wanted for the new header pipe with muffler. Folks were mystified about not having muffler pressure and what did I do with the vent line. Heck, this is how we used to fly all of the time before mufflers came out. I'd show them the vent line hanging slightly below the bottom of the fuselage and they couldn't believe that the carb would work that way, but they did see it working.


Ed Cregger