CurSedVoyce
California Hillbilly
With Echo, you can conservatively modify the muffler simply by removing a restive plate between the spark arrestor and the directional plate. Most have them. Like a foil style gasket with a small hole under the directional plate. Four screws is all holding it to the muffler in most cases. Or, just cut the restrictor plate the same size as the exhaust hole and reinstall.