Relationship between idle jets and idle mix screws Options

[era vulgaris]

How much can one compensate for the other?
For example, with larger jets and idle screws further in, could you tune a set of carbs identically to another set of the same carbs that had smaller jets with the mix screw further out?

I want to experiment with going a little leaner at idle and seeing how my engine likes it. I'm trying to decide if I should order a smaller set of idle jets or if I can achieve the same result by just turning the screws in further. Basically, what is the difference? Don't they achieve the same ends? Obviously there's a limit on the rich side because there's only so much fuel a jet will allow to flow. But if you're trying to lean it out, what's the difference between going to a smaller jet or just turning in the screw?

[rhodyguy]

See if you can achieve a stable idle @ 950rpm.

[era vulgaris]

After 3-4 turns out, idle mixture screws are not effective. If you find yourself in that range you should increase idle jet size. I like to be between 1.5-3 turns range for good resolution. this will not effect transition. If your carbs do not have chokes and runs real good when cold, I can assure it will be too rich once warmed up. The 914-6 folks know all about that. Also, timing is everything with carbs. A lot of the time carbs take the blame for wrong initial timing and /or curve. Tuning carbs before timing is putting the cart in front of the horse.

Timing is set at 11 degrees at idle and 28 degrees at 3K rpm, which from what I could gather from searching is Jake Raby's recommendation for a Mallory Unilite. Idle screws are just over 2 turns out.
Carbs don't have chokes (DRLA 40's, in my signature), and run a bit rough when cold. Like I said, 99% of the time everything everything is fantastic. I just have this occasional dropout at idle. When I say I think it's running too rich, I'm talking like maybe 0.5 units on the AFR gauge too rich. Not a massive amount.

IT sounds to me like 1100 rpm is off the idle circuit and into the transitions. try to set the mixtures at a slower speed (less throttle plate opening)Last steps this set the idle speed

-Robert

See if you can achieve a stable idle @ 950rpm.

I'll try and get the idle down a bit. It just doesn't seem stable under 1K rpm, which is also what makes me think it could be due to it being too rich at idle. Every other part of the rpm range is absolutely killer. I'll try turning the mix screws in and stick with the jets for now, and see where that gets me.