I'm on the 5th tank of fuel on a Husky 543xp so it was time to open up the muffler and see what it gains. The process is pretty easy with a dremel, drill bits, and a small MAP gas brazing torch. The stock muffler is very plugged up, but easy to fix. Cut the small spot welds with a disc, lift the deflector, drill two large holes through the baffles, get all the metal frag removed, and braze it back up. The fire screen goes back in and some BBQ paint makes it look new again. With everything the same as "stock" (same gas, elevation, etc) the saw gained 500 RPM and needed about another 1/4 turn out on the high speed needle. Picked up some power without being a whole lot louder.
