Hot idle adjustment screw

[Jim Yergin]

I have a Holley 4000 carburetor in my '56 Thunderbird. I cannot see what the hot idle speed adjustment screw pushes against to raise and lower idle speed. Here is a picture of my screw. Am I missing a part or do I just not understand how it works?
Thanks.
Jim Yergin

 

[scicala]

The hot idle speed adjusting screw (with the spring on it) is supposed to contact that round pin directly in front of it. Either the dashpot screw on the throttle lever is adjusted too far out, or the fast idle cam on the other side of carb isn't dropping (choke not all the way opened ?). Or the return spring on the throttle linkage isn't working.


Sal

 

[Jim Yergin]

Sal,
Thank you very much.
Jim Yergin

 

[Hot Rod Reverend]

I just posted two videos to YouTube, and I have quite a bit on these 4000s on my personal website. I do not know near what Sal knows - he has been a tremendous help to me! But maybe some of the footage you see will you identify what you need.

Link to YouTube: https://www.youtube.com/watch?v=zQlQeFVJjo4 (there is a part 2 as well)

and then my blog posts with further information:
https://www.hotrodreverend.com/blog/categories/fuel

enjoy...

 

[paul2748]

Took a picture of mine - yes, rests on the rod. Looks like you linkage need adjusting or the screw has to be adjusted in some more