Yeah, this thing vibrates a little more than a glow and is noticeably louder. I put red RTV around the muffler body (still used the skimpy O-rings with it) and used blue Loctite on all of the screws and muffler bolt. No more leaks. I had to retighten the muffler bolt today after 4 flights but the screws holding it to the engine are still tight. Are you guys having any issues with the amount of black residue it produces?

Dave