Idle mix screw O ring ADFA carb

[Scotsman]

Can anyone tell me the size of the O ring on the ADFA32 carb? Can't find one in parts.
Thanks

[bradartigue]

It should not have one. The mixture screw isn't fully seated, it has a spring.

[Scotsman]

Brad

Thank you for your info.

A parts supplier told me he had a similar problem of an unresponsive idle mix screw. He found what he called a broken O ring, fixed it and his problem. I assumed this would be part 81(mislabeled 82? ) listed as a washer in Bruce's part bin list. Maybe same thing.

Unfortunately, I no longer have knowledgeable local mechanics and have since had one expensive and disastrous carb "fix" . So, after 37 good years I am trying my own fixes, tho I am no mechanic and rely on experts like you in this excellent forum.

Here's my problem. My car still runs well when warm - good power, smooth acceleration and idles nicely about 900 rpm. It starts immediately from cold but now idles unevenly and stalls until the choke opens or is held open or I increase revs with pedal or throttle control knob. Revs respond to idle speed screw but not the idle mix screw. Solenoid seems OK and I can find no leaks by spraying. I think it is running rich and losing a lot of gas. Gas comes from the progression holes (44 in your Fig 28) but initially dribbles down the aux. venturis rather than as a spray and puddles above the spindle (23 fig 30)

I felt no spring when first adjusting the mix screw so backed it out in car and sprayed with carb cleaner and WD40. I then felt cranking when tightening but still no change in revs even when fully seated. I backed it out 2 turns from seated. Still won't idle when cold and uses lots of gas on low idle.
What do you think may be the problem?

Thanks.

[bradartigue]

Replace the screw and inspect the threads in the carb body. Use a non hardening sealing around it. But I doubt it is the mix screw causing excessive fuel consumption, your idle set screw may be set way off or your idle jet is too big.

[Scotsman]

Brad

Thank you for suggestions.

The idle jet is still the original so may not be the problem unless it could have been recently damaged by setting the idle speed screw.

I am puzzled why I get good idling when engine is warm or choke is opened but not with cold starts. Are there different controls for these situations?

In my misguided tinkering I also altered the throttle cable tension (nut on threaded bolt (shown in post by garion "Throttle linkage adventure, Nov 12, 2012). I don't know if I returned it to its original position. Could this be a factor? If so, how do I reset?
Thanks

[bradartigue]

The idle jet isn't on the mixture screw. The mixture screw is the mixture screw, the idle jet is the idle jet. The screw is on the bottom center of the carb, the jet near the top. Find a schematic, check it out.