Muffler very open. A 1.5" X 1.5" square under the hear shield with coarse screen.
Tank vent fine.
It's flooding with prolonged idle. If I let it idle for 20 seconds and pull the trigger, it wants to die. Gets going, blows out smoke, then cuts. If it's tuned correctly, it works fine. It only does it if it sits. It's dumping fuel at idle.
It probably needs some passage blocked in the carb or something. Does with both carbs.
I just used it to cut up some 10" diameter branches that fell during the wind storm here the other day. It performed great in the real world. Just need to not let it idle for prolonged periods, which is bad with a standard oiler 026 anyway.