Air valve dashpot

[Zogbert]

I rebuilt the MonoJet on my 72 C10.

The 250 runs great, but I did notice something that might be a problem. I was tinkering with the air valve dashpot, and noticed that when I drew air from it, it allowed air in somewhere. Is that normal, or should it be air tight?

Thanks!

[geezer#99]

Yup!!
That's normal.

Does it hold a vacuum?

[Zogbert]

Yup! Thanks!

[RichardJ]

Looking at some of your old posts from a year ago, you have a MonoJet and most of the smog equipment has been removed.

You don't have an "air valve dashpot". I'm not sure any carb does. "Air Valve" is a term used to describe dozens of different items, used for many different things.
"Dashpot" on a carb is generally used to slow the closing of the throttle so it doesn't slam shut. They are often used on manual trans cars. If the throttle closes completely when shifting, manifold vacuum goes up and pulls extra fuel through the fuel jets. Not needed. If the throttle doesn't completely close during the shift, then that also reduces the accelerator pump shot. Again, not needed when shifting.
This reduces fuel consumption and emissions.
A dashpot is usually a friction device and has no vacuum connection.

You probably have a "Choke Vacuum Break" and it may have a Purge Bleed Hole. Cover the bleed hole with tape and when you apply a vacuum to the port, the diaphragm should pull in and stay there until the vacuum is removed.

[Zogbert]

Thanks. That is the case. It's working properly.