I read through some of that. That reminded me of what it looks like with too much emulsion.
If you are logging AFR and you see saw tooth lines you almost always have too much emulsion and you are seeing what is called slugging.
You get a slug of fuel and then a slug of air and it keeps alternating.
There is so much air being introduced to the main well that the bubbles start to coalesce into bigger and bigger bubbles and you get that big slug of air.
I always forget to mention this because I don’t think about it until I’m putting a carb together but I think it’s pretty important so I just do it.
That is I always make the size of the main well a straight diameter. As it is, they are tapered and the main well is smaller at the main jet.
Somehow this affects what the air does as it’s introduced to the main well. I always thought the taper was there because it had a function, but I learned the main well is tapered because it’s the only way they can get the metering block off the mold.
What’s funny (funny as in strange) is that even “billet” metering blocks have tapered main wells.
That tells me that they aren’t really billet but castings that are fully machined.
Either way, I take the taper out of the main well when I build or modify a carb.