Cylinder 3 misfire at low revs

[His Dudeness]

To me it sound like the pilot circuit is blocked on carb three. To test if the pilot circuit is blocked try starting the bike on choke. Don't touch the throttle just leave the choke on and let the bike idle for a couple of minutes. Check does cylinder three start to get warm when you let it run on choke. The choke circuit is a different circuit to the idle circuit so if it does get warm on the choke but it stays cold off choke it suggest the idle circuit is blocked. You can test if cylinder three is getting warm up by throwing some water on the headers and see if the water dries.