Carter BBD tuning issues

When the engine is cold the thermostat rod wants to closes the choke 100%.
To start push the pedal down once and release, this allows the choke to close and the weighted fast idle cam to fall catching the screw and opening the throttle blades.

Now you start the engine and it creates a vacuum THIS pulls the choke blade open slightly. (Choke Pull Off or Kick). I'd set my 1970 at 1/4 inch.

As the engine warms the thermostat rod tries to open the choke and take it off of fast idle, this will only happen when you push the gas pedal again.