In most cases it goes in the plastic tube thingy that slid up over the brass nozzle.
if there are 4 passages in that tube, there should have been 2 of those orifices. (In most cases at least.)
I tend to blow them out-and away- when I am cleaning a carb with compressed air.
Its the jet and no wonder its a "little" rich. would probably be smoking.
get the model and type number and look it up. should be a breakdown picture of your carb. on the engine breakdown that will show where it goes.