Hot Rods Need a Holley expert

Holley built a series of carbs with reversed idle mixture adjustments. You turn them in to richen and out to lean. On a normal carb you begin the adjustment process by carefully turning the screws in until they seat then backing them out but it gives you a place to start by bottoming out. On the reversed adjustment you would turn them out to close but is there a stop or do they merely screw completely out of the carb. What do you use a starting point?

 

Starting point would be to set the idle transfer slot square and then play around with the mixture screws.

 

X2 with RMK57 , there alot more then just mixture screws for turning a carb to run correct , you will need a good under standing how a carb works /function from idol cruise to wide open.
Turn in & back out 3 flats turns ,each side or if 4 corner a turn 3 1/2 -4 out On each .
A big face Vac gauge will help For Mixture settings, What the Engine needs/likes .
What size carb?
What size motor ?
Cam ?
timing ?

 

I think the starting point with those is to turn the screws 1.5 turns out from fully seated (as a baseline starting point.)

Then throw it in the garbage can. Go for a beer.

 

Yep!....^^^^^

 

Well, to try to actually...answer woodies question...
Yes, they will still come out of the metering block.

I would start at the same 1-1/2 turns out, knowing that 1. 1-1/2 may be too far out, and 2. remember to go "out" to lean the idle system. Go through the task twice to make sure the engine is happy with your adjustments.

In any case, engine to full operating temperature. With an automatic trans., I put the trans. in gear, block the tires/have someone hold the brakes, and adjust the idle speed and mixture.

Mike

 

Thanks Mike VV, RmK57 I appreciate the help, being a smart ass myself I can't really complain about some of the other answers.
For 19Eddy30 it's a 350 over .30, the carb is a special Holley 4160 600cfm that has annular boosters all around, vacuum secondaries, as well as the reversed mixture adjustments. The cam is a CompCam dual pattern with 255 lift on the intake and 261 lift on the exhaust. Duration is 203 intake, 212 exhaust. Initial timing is 15°, 28° mechanical and 15° in the can. The intake is a Thermodyne Driver (but that's a story in itself).
The question came to me because without a stop of some kind in place if you try to set the needle at fully closed it would back out of the orifice.

 

It should stall the engine well before the needle falls out if the carbs set up right and no vacuum leaks.
With a regular Holley I start with one turn out on each mixture screw and adjust from there. Adjust until the engine starts to labor or run rough then in your case back out the screw 1/4 turn, then do the same for the other side. Try and keep them equal turns out.
My 950 HP Holley has 4 corner idle and I'm about 7/8 out of a turn from the bottom.

 

That was a factory or OEM carb, correct?

Yeah, I was being sarcastic, but I've not heard a lot of love towards those. Maybe they are outstanding depending on what you want to do, but ... Most everything I ever read seems to be "Avoid". Maybe the detractors don't know how to set them up right. That would not surprise me either. But there isn't any upside to running them, near as I can tell. Maybe if only factory OEM carburetor is allowable for inspection purposes, it might be worth some coin to the right guy.

If you search "reverse idle mixture screws" you'll find some interesting archived discussions on these.

 

Truck....not to worry sarcasm is welcome anytime. This particular carb came as a set with the Thermodyne Driver intake that is on the car. Obviously with a woodie I'm not doing any racing with it but I want good throttle response, no bogging and maybe a little extra "git". I've run this carb for probably 15 years and have been very happy with it. The annular boosters on the primary and secondary side give it very smooth transition.
I was just out in the garage messing with the distributor and after removing the vacuum advance mechanism I noticed a few drops of gas come out. I tipped it up vertically and pumped the lever a couple of times and it spit out probably a tablespoon or more of gas. Can't imagine how gas managed to get in the can. The diaphragm seems to be ok it still functions and holds vacuum as it should. I had it attached to the manifold vacuum port beneath the front of the carb.