I guess I'm not as familiar with these carbs as I thought I was.
I noticed that on the sides of #3 and #4 carbs there are these extra spigots:
I thought they might have been the carb bowl vent/overflow outlet but noticed that they are not present on carbs #1 and #2. Looking at the bottom, there are no vents:
I haven't confused these with the fuel inlets because I know where they are. Can anyone tell me what these two extra nozzles are for?