http://www.wind-drifter.com/technical/WalbroServiceManual.pdf

At around page 8 they show diagrams of what I'm thinking.

Low speed jet and a High speed jet to tune the fuel air.

Why cant this idea be used and ditch the pulse membrane pump for a float chamber fed from the fuel pump?! Keep reading and it even shows you how the accelerator pump works.

Its kind of like a weber, but why open and fiddle with jets when a small 3mm flat head screw driver is all you need to tune it? Biggest walbro make is 25.4mm (venturi) and these carbs are used on 100cc 2 stroke motors, so on a 200cc four stroke (x4 cylinders) gives us 800cc - needs to be a bit bigger for A series motors.