Not sure how it works.
I have never read of this sort of setup being used on anything other then a log manifold. As I understand the linkage - only the outer carbs have split throttle rods - the center is solid and is where the gas pedal bell crank is attached. This allows for attachment of an inner linkage and an outer linkage on either side of the center carb throttle rod - but these linkages are rigged to open at different progressive rates. The delay in opening on the outer carbs is typically accomplished with a slip-stop setup. A shorter distance on the inner linkage stop would cause the corresponding halves of the secondary carbs to begin to open. As travel continues the somewhat longer distance to the stops on the outer linkage would cause the other halves to open.
The setup pictured doesn't appear to be progressive/split at all. Only the center carb has a choke and there is a bell crank just behind it. This crank seems to act directly on the front carb throttle rod which in turn acts on the center carb and then back to the 3rd . . .
Also, with this sort of dedicated trip one needs a power valve on every carb. With split throttle shafts the linkage would be further complicated since the primary halves would have to include the power valves.
regards,
stock49
