With the carb back on and the throttle servo reset started and ran the engine, lowest possible idle when leaned out was about 1600 rpm, this engine would tick over at just over 1000 rpm with the WT 962 carb installed. When I look at the throttle disc you find the small slot where the idle jet is and there is also a second slot about 160 degrees across, I have not seen this second slot on other carbs.
When I compare the slot in the WT 962 carb it is much smaller than either of the slots on the ZAMA. I would estimate the slot area to be about 6X that of the WT962. I would like to have the idle set before completely the final tuning. Going over the gaskets and heat isolators, might find an air leak.
Here's a of the engine idling after landing, the speed is 1020 RPM.