Carburetor Idle Stop Solenoid Configuration

340inabody, an "idle stop" is what it is. It is a plunger that extends when power is applied to raise the idle to compensate for the rpm drop from the AC load and is adjustable. Not going to help you prevent dieseling/run-on. Timing adjustment and/or fuel quality will help with that.

Some carbs have a solenoid that stops fuel flow when the ignition is shut off but those carbs are tiny and would never be used on something like this. There is no easy way to instantly stop flow from the bowl unless the carb was designed for it.