Carb tuning, larger accelerator pump nozzle?

Rat,
I think we are close to being in agreement. The size of the AB controls the start of the cct, as discussed earlier in the thread. Once the cct is started, the size of the AB, number, position & size of emulsion bleeds controls the amount of mixed fuel & air that gets delivered from the booster.
You have to have some sort of AB in the cct, otherwise the fuel will be syphoned from the booster until it empties the fuel bowl.