Is this carbon buildup? And how can I fix this?

Jadaharabi said
As 318wr said a cross plug wire or even a bad plug wire. Had that happen with a new set. Looked everywhere for the miss after a tune up. It was one of the new wires.

Only 2 listed are even relevant to the sooty carb. He would have to be driving the crap out of it while in that condition to look like that..