I have a '69 AVS, 4618S, and am wondering about a few things. This plug is supposed to cover an off idle adjustment screw, according to the FSM. Should I gain access to it for cleaning and adjustment?



There is a spring inside that presses against a ball bearing, and on the top, it opens to the atmosphere.



It allows extra air to enter after the idle mixture screw, which itself just adjusts how much the idle fuel is diluted.



This is where the air comes from that goes through the idle mixture screw, and into the idle circuit.



This is where the idle limiter screws, as the FSM calls them, are located. They are covered by a plug and staked in. Should I gain access to them for the rebuild also?



Finally, there is this thermostatic air bleed, which I thought was only on A/C equipped cars, like the 4640S carb. It looks like it opens to a blind hole. I don't see any holes inside. Wonder why they wouldn't eliminate it on carbs that aren't drilled for it.





Why are the Edelbrock mixture screws up on the diagonal part, and the Carter has the same plugs next to the PCV port, and their mixture screws are below those?