Hi all, I would appreciate some advice on a correct 2100 2 BBL carb for a 292. The truck is a 1964 F100 4 speed. The engine casting number is B9AE is a rebuild @.30 over, had Mercury valve covers and has a mileage of just over 30K. The carb is a 2100 # C2 AF AA. The jet size is ¼” x .048 and were replaced with same size new jets and other new parts. The venturi stamp is 1.02. 
The engine has a rough idle but drives fine though seems under powered. I had flushed and cleaned the fuel system, including the carb, used a gauge to set float, new filters- fuel pump, and sea-foam in 3 tanks of gas. When I removed the old plugs to oil cylinders before starting, they were black. I installed new plugs and after a few 100 miles the plugs are black. There is a heavy smell at idle. The air filter is new hand choke is wide open. When I adjust the fuel mixture screws, I turn in and as I back them out the better (Not good) idle is achieved at ½ to ¾ of a turn. Turning out to 1-1/2 is a rougher idle.
I would like to keep the truck as stock as possible. I am not opposed to replacing the carb to save time and headaches. If I do replace, I would like to upgrade if needed, any advice on what carb and where would be greatly appreciated. Thank you in advance for any help.

It sounds as if you have covered quite a few bases concerning the carb. And while you are obviously experiencing a rich mixture, I do wonder about how hot a spark you are getting at the spark plugs. Weak ignition would cause very much the same thing you are experiencing. What is the current condition of your ignition components and what exactly are you running for ignition? 

Daniel Jessup

Loveland, Ohio

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

i can’t remember everything about an Autolite 2100 but Did you check the economizer valve? I believe is under the plate with the 4 screws. It’s on the bottom of the bowl. A leaking one will cause an over rich condition. 

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Thank you for the response! I did read about the blue spark required. The previous owner kept great records of repairs and parts. The wires, cap, rotor, points and condenser had been replaced on the stock distributor shortly before being parked for years. I have not spent any time on the ignition system. I will focus there. Funny, I sold my dwell meter years ago thinking I would never need it again. Maybe the packrat mentality has it advantages! Thanks again for the response, I will work on this soon. 

A rough idle could be attributed to valve lash settings, poor seating valves, broken or weak valve springs, ignition timing, other problems within the ignition system, a vacuum leak, or carb issues.  Not a complete list but it’s a start.  A vacuum gauge check of the engine at idle will help to verify that all the valves are sealing and the ignition timing is in the ball park.

The 1.02” venturi carbs are notoriously undersized for even a pickup Ford Y but are normally good drivers.  Those Ford flattop carbs are prone to idle issues at the fuel discharge nozzles when they do not seal good to the carb body.  A single flat bladed screw is all that holds the discharge nozzles in place.  Problems arise when the fuel discharge nozzle assemblies are overtightened and subsequently become warped.  Once warped, the quick fix is either double gaskets or a thicker than stock gasket for that location.

You do give some good detail on the idle mixture screw adjustments and those sound good which sort of takes warped discharge nozzles from the top of the list and puts it a lower level.  Discharge nozzle warpage cannot be eliminated at this point as you do mention that the idle is rough.  With that in mind, then the float level being too high or the power valve (economizer valve) not properly sealing comes to mind.  Old power valves do not close at their rated values due to the rubber diaphragm within them becoming stiff and less flexible.  But assuming this valve is a new one, then I would be looking at the gasket that seals the power valve to the body.  While not a common issue with the power valves, look at the angled fuel seat in the power valve and ensure it is smooth and seating fully when pressing it closed.

Lorena, Texas (South of Waco)

Thank you for all the suggestions! it is greatly appreciated. I finally had a chance to start working through the list of possibilities. The first thing I did was the spark test. I removed the coil wire and grounded it on the valve cover stud. The spark was a yellowish orange not the required blue. The cap, rotor, wires are old but show no wear. I will focuses on a new coil, points and condenser. If this does not cure I will continue to replace ignition parts.
I an not opposed to replacing the carb to achieve the best possible stock performance.  Any suggestions?

Thanks again for all suggestions. It is great to access this firsthand knowledge. I have a grandson that is interested in the truck and willing to learn. The first time he got into the truck he wanted to know where the button was. I asked, what button?  He replied, I want to put the window down, where is the button! 
Thanks again