I see it every time I take apart a Briggs and Stratton carb from a Quantum engine. Some have one offset (fixed) brass emulsion tube with another hole that is blind, and some just have the one offset hole.
When I tangled with a Honda and their clones , the main jet was screwed into the base of the emulsion tube housing. This is a completely different setup. I opened up the idle and main jets and it's much better now. HF Micro drills to the rescue.