I am not familiar with that carb either, but I am familiar in general with "anti-dieseling" solenoids.
These came into use way back (60's in Cali' and early 70's elsewhere) as a means of preventing the engine from "running on" after the engine ignition switch was cut off.
When emissions regulations caused OEMs to lean out the air/fuel ratio, combustion chamber temperatures rose significantly.
The higher CC temps would often cause the engine to continue running (though very poorly) with the diesel priciple on the idle fuel circuit still being active due to venturi vacuum applied to the pilot jet port.
The anti-dieseling solenoid was introduced to the automotive industry as a way of positioning the throttle shaft at a point that would expose the fuel pilot jet port to venturi vacuum whenever the ignition was in the start/run position, but would allow the throttle plate to drop to the fully closed position and deny vacuum to the idle fuel port in order to kill the engine in a dependable fashion when the ignition switch was turned off.