Thanks Rick, but I cleaned the screen when I removed the carb and made sure it was clear with compressed air. I cleaned the tank of some dirt too. And, I tried to see if the fuel cap was breathing, but I've never seen one like this before. Metal tabs hold it in place with a half-turn. There's no evidence of a pinhole to allow breathing. I tried to run the engine without the fuel cap to see if it made any difference and it did not matter - it still wanted to slow down and quit.
Charlie
January 2007