Smog-era idle settings

[Glutenfreecarbs]

My apprentice and I finally had to remove a pair of these a few weeks ago: idle mixture screw caps, still intact on a random 17083226!

Out of morbid curiosity, I turned them clockwise and found that the stock setting was only 1.3 turns from lightly seated. Oof; that had to be terrible for idle quality, especially with the limited choke and timing settings of the era.

I bet there are old fleet and dealership mechanics whose hands are still sore from hacksawing and punching these out....

[Glutenfreecarbs]

Pic is attached; I guess the embedded file misfired..

[Cliff Ruggles]

2-3 seconds on each side with an angle grinder, couple of solid hits at a 45 degree angle with a sharp punch and they just about fall right out. 

I just rebuild two mid 80's Olds CCC carbs for a local customer that still had them in place.   Took less than 30 seconds per side to get them out.

The holes are so small under the mixture screws on the later carburetors that you very quickly find out than backing out the mixture screws provides limited adjustment. 

Some of the later truck carburetors actually had a pretty "generous" idle fuel delivery plus LONG transfer slots so they don't need backed out very far on some carb numbers......FWIW.....