The Stovebolt Site Forums The Shop Area Engine Shop Carter YF2100S by Motorcraft

Hello all
Is anyone else using a Carter/Motorcraft carb? I’ve been having trouble getting my 50’ truck with a 57’ 235 running good. Since I swapped the Rochester carb from my 49’ Burb with a 54’ 235 the truck has ran great with trips up to 65 miles one way
This is the first time the truck has ran good for me since I owned it. I have been told by a mechanic and carb rebuilder that this carb may belong to a larger ci Ford engine and may be my problem running rich.
Should I start looking for a Rochester for this engine too?

2100s is a GM model as far as I know. Does is say Motorcraft?

There is a Carter YF designed for a Ford inline six, 240 or 300 cubic inch, and yes, it will run VERY rich on a stovebolt Chevy. Don't try to rejet it- - - -get the proper Carter carb for your application. There are a lot of other internal differences besides just the jet size. RUN!- - - - -do not walk away from anything that says "Rochester" om it!
Jerry

Yes it says Motorcraft

Jerry can you help? What is the correct Carter for 235ci
Also, I think you prefer Carter over Rochester? What are the advantages

Check Jon's website (Thecarburetorshop.com) I think that's right, anyway. He has a list of correct Carter carb numbers for various Chevy sixes, all the way up to the 194-292 engines from the 70's and 80's. There's quite a history of the Rochester/Carter dispute, dating back to at least the late 1940's when GM quit buying Carter carbs to run on Chevrolets and started manufacturing their own. The CEO of Carter vowed to sell a million replacement carbs for Chevy engines. After a few years, when the millionth Carter OEM replacement Chevy carb came off the assembly line, Carter had it gold plated and presented it to the CEO of General Motors. Rochester carbs were built to last through the warranty period for Chevy products, with little or no concern for longevity. Carter carbs were designed and built to be repaired, numerous times if necessary, and they last much longer without the rebuilding difficulties usually encountered by Rochesters.

Try this link:
http://www.thecarburetorshop.com/Carter_YF_Chevrolet.htm

Jerry

2100s was for the 235 (1953 to 1956). Also on 235 were 788s, 789s, 966s, 967s, 2101s and 3211s. There were a couple of numbers in the 800 number series reserved but there was no production (890s and 891s)

If a mechanic and carb rebuilder told you that, they might be confused. No, I would not look for a Rochester to replace it. The 2100s was a good carburetor.

If you want to clean and rebuild it and check to see what you have in there at the same time, here is the Carter data and notes I have:

float setting: (with no gasket but with float resting on seated needle) 9/32" drop: 1 1/4" adj by bending stop tabs on float arm
vents: outside, no. 12 (.189 inch) drill, inside balance vent size, no. 42 (.0935 inch) drill in air horn
gasoline intake: spring loaded needle, size no 46 (.081 inch) drill in needle seat.
Low speed jet tube: size no. 70 (.028 inch) drill. Bypass in body, size .069 inch diameter. Economizer, size no 53 (.0595 inch) drill
Idle port: upper port, slot type, length .190 inch width .040 inch.
idle port opening: top of port .143 to .147 inch above top edge of valve with valve tightly closed.
lower port (for idle adjustment screw): .0615 to .0655 inch diameter
set idle adj screw: 1 to 2 turns open. For richer mixture, turn screw out. Do not idle below 425 rpm. Powerglide at 475 rpm
Main nozzle is installed permanently. DO NOT REMOVE drilled passage is size no 59 (.041 inch drill)
Metering rod: economy step .067 inch diameter, middle step tapers to .060 inch power step is .050 inch diameter.
Metering rod jet: .0945 inch diameter
Metering rod setting: see company instructions/adjustments
Accelerating pump: diaphragm type, vacuum and mechanically operated. Pump jet size 74 (.0225 inch drill) intake ball check seat size no 40 (.098 inch drill), discharge needle seat (in body) size no 42 (.0935 inch drill), vacuum restriction in flange size no 55 (.052 inch drill), vacuum passage (diaphragm bleed) size 56 (.0465 inch drill) and pump bleed into bowl size no 75 (.021 inch drill).
Pump adjustment: see company instructions/adjustments should be adjusted anytime the carburetor is reassembled.
Choke: manual
vacuum spark port: horizontal slot type, size .125 by .040 inch. Top of port (early prod) .030 to .040 inch and (late prod) .035 to .045 inch above top edge of valve with valve tightly closed.

Good luck, hope it helps.

One other idea...if it says Motorcraft, where does it say that? Lately on eBay I've seen a rash of "frankencarburetors" being sold by a couple of different sellers. They are all Carters, but the air horns and bowls are totally mixed up. You should avoid these completely. Take a look: https://tinyurl.com/y8run522 This is no more a 3211s than it is a bowling ball. The 3211s had an automatic choke which was cast into the air horn and could not be removed. Look at the final image and you can see the air horn does not match the float bowl at all...there is an open space at the top where gas will slosh out at every turn. Search for 3211s and you'll see another person trying to sell one which has been cobbled together from assorted parts.