questions about throttle control diaphram/dashpot

[lx 1986]

On the throttle control diaphragm I see an adjustment screw on it.

If I turn it counter clockwise does it increase or decrease the vacuum?

Does more vacuum mean that the idle goes up or down?

I have a 2bbl Keihin carb on a 86 Honda Accord LX, auto trans with ac.

Here's a pic of the screw I'm talking about. This is not my carb but one similar to it.

http://i346.photobucket.com/albums/p413/browsers2010shoppers/example%205%20of%20carb%20-%20Copy_zpsbyj0svjw.jpg (http://s346.photobucket.com/user/browsers2010shoppers/media/example%205%20of%20carb%20-%20Copy_zpsbyj0svjw.jpg.html)

[Buzo]

Hello. Its been long time since I don't post in this forum. But the screw in your picture is called automatic idle speed adjustment. It works together with the vacuum actuator. If the rpms go down, the actuator will extend. And if the rpms go up the actuator will retract and so on, keeping the rpms constant. It would be good idea if you check if all the diaphragms hold vacuum. I never found a good way to repair those that were found shot.