I've changed the wire too.....I thought that might have been it, as it was a bit rubbed.
The one thing I don't have is a spare carb.....I've been wrong before, but it has to be the carb.
Throw any other ideas at me, but I bet I've tried it all.
I can leave it idling sitting on the ground and it will intermittently "almost" burble out and die, like it gets a gob of fuel tossed in, if that makes any sense.
I took it home on the weekend and it ran and cut flawlessly for almost a whole tank and then died when it came back to idle and that was it......Even if you hold the throttle open and pull your heart out, it won't even sputter.