What is a "double-pumper" carb?

[Woodz428]

Thanks for the info Sal. I had forgotten about the center squirters. While they were several sizes made there are now only a couple, actually, I only saw on that wasn't a marine one. For Anthony, it has a single 50cc pump up front and uses a nozzle in the middle of the carb to spray both primaries and secondaries. They way they are able to do this is by making the secondaries 1:1 with the primaries, where as the double pumpers have a "progressive" secondary and need the extra pump since they do not open simultaneously with the primaries. While you could potentially operate one on the street it would be pretty twitchy. As noted they are race carbs, designed for 2-4 set ups, also notice there is no choke.
That's the 600cfm 4224. The 9776 isn't listed in my Holley catalog, although it is listed in the reference pages of parts. So it may or may not be a center squirter like the 4224.