Kahuna
The stock DL-50 muffler is working fine for me. The only drawback with it is the fact it is a side mounted muffler and depending which plane you will be mounting the engine in you may have a problem with cowl interference. Mine is in an SD 30% YAK 54 and the muffler hit the side of the cowl. I chopped an angle off the front/side, had an aluminum piece welded back in place to cover the hole I had made. Cost me $10 from a local welder. This solved my problem, but wish the DL-50 came with a Pitts style wrap around muffler instead of the side mount.
Rcflyrc3