What is this gizmo on the back of the air horn? What does it do?
That is the Hot Idle Compensator. If the inlet air temperature at the carburetor is high, the compensator will open and allows air to to bypass the throttle plates. This was used to improve idle stability.
Coach Jack
Thanks, Coach. Now that I know what it’s called, I see there’s lots of info about how it works on the internets.