What is this hole for???

[johnson1550]

Can someone explain to me what this hole is for? I just rebuilt my carb and this hole was plugged with a bolt. I removed it because it did not look like it belonged there. The car has a huge vacuum leak with this open and of course the idle wont come down. Any help would be appreciated. Thanks

 

[mguner]

I believe the hot idle compensator should attach there. A bi-metal spring with a brass cone attached to it... or the tower style.

 

[johnson1550]

I believe the hot idle compensator should attach there. A bi-metal spring with a brass cone attached to it... or the tower style.

So there should be something internal? There is nothing in this hole and the top gasket has a hole that lines up with it as well. There is a lot of vacuum there when the car is running. All the pictures I could find of this year carb all look like the hole is there and unplugged.