I didn't say the carburetor was mounted on the car. It was not.
It had in fact been completely disassembled and cleaned, with carburetor cleaner, then alcohol, then soapy water.
After which, some chalky deposits remained in the emulsification tubes, and some carbonaceous deposits remained in the transition jets.
Their presence was detected with the smoke.
They were mechanically removed.
Their absence was verified by the smoke.
Then the carburetor was reassembled and reused in the normal way.
That (Ford/Motorcraft) carburetor would have given the HSE folks fits anyway; the normal procedure for adjusting the float level required measuring the float level with the entire top of the carburetor removed, on a running engine. You were supposed to stop the engine to bend the float tangs, because bending them on a running engine would squirt gasoline from the float needle up into your face; this, I know.
Mike Halloran
Pembroke Pines, FL, USA