Brand new good times

[hiball3985]

Not sure if the crack would effect it. I would be looking at a plugged idle air bleed, or idle fuel passage. Sometimes removing the adjustment needle and a good blast of air will clear it.

[Swank]

Can you do that with the carb still on the engine (without making a massive mess)?,   ...or should it come off?

[thomasso]

Have you checked the intake manifold gaskets, I recently had problems maintaining idle speed,setting timing, mixture adjustments,  I too went thru the carbs and distributor.  the engine ran OK but car would actually vibrate around 2K to 2.5K when driving and exhaust sound was very raucous and would backfire occasionally.  Vacuum was around 15 but at this altitude thats almost maximum.  Finally pulled the intake and the the gasket at the RR. port had sucked in and was sucking air.  Runs great now.

[hiball3985]

Watch the video, may be of some help. The passages are so small the littlest piece of crap will block them. I use welding tip cleaners to clear them.
https://www.carburetor-parts.com/Idle-Circuit_ep_1795.html

[Swank]

UPDATE
Update from the last idle screw deal.   Actually had fixed it a little while back, but forgot to leave a state-of-the-union follow-up.
I had pulled the venturi and found, as stated here previously, a small piece of crap, stopping up one of the emulsion tubes.  Im always careful to keep this thing tidy, so not sure what it was or how it got in there, ...but whatever,  that idle screw works again.
Since that fix, I've been able to put a few miles on it and get everything nice and warmed up.
Found I was having hard starts while hot.   For cold starts, step on it twice, and it'll kick off before you have a chance to let go of the key.   But if it sat for 10 minutes after running, it was cranking for 15-20 seconds and slowly stumbling into running. Been doing that for the last week or so.  It would crank hot right after you shut it off, but if it sat between 5 and 20 minutes it just rumbled around.
Did a quick "hot hard start" search, and the easiest least invasive solution I found was to lower the fuel float a notch.
That completely worked, at least so far it has.
Had it nice and hot today, waited 15 minutes several different times to start it back up,   starter would only get about 3 or 4 grunts in before it cranked each time.
Having a little more confidence that I'll get back home, makes taking this thing out a better time.

[RICH MUISE]

You're learning the skills to "get it back home"......that's something I never had and why I went new school with my drivetrain. Honestly never had the desire to learn it.....so kuddos to you for doing so!

[djfordmanjack]

great news !
Another trick that can often help with hot starting issues is slowly depressing the accelerator pedal ( not pumping) to 1/2 or 3/4  throttle and start with pedal in that position, of course let go as soon as she fires up. some cars will only start that way when hot and its even sometimes mentioned in the manuals.