I know the idle screw pinhole, transition slot/series of holes for the butterfly edge. What exactly where butterfly is now at when transition port(s) and the main booster interact?

emulsion tube, there is videos of weber emulsion installed in a clear plastic with drilled passageways in action but the guy who did this did not say when it is happening with engine vs emulsion tube goes through different phases of low, medium and high speeds? All I did saw was "drool" at low speeds, then "boiled like mad" then quit boiling and kept drooling fuel at higher rate.

Oh yes, I noticed that Weber uses caparillary action to keep fuel at the edge of emulsion ports while holley emulsion tube does not. Explain?

Trying to understand the carb better. Yes have the HP weber book and innvotive's forums.

Cheers, Wizard