Carter Afb Four Barrel

This new to me dauntless came with a offenhauser 4 barrel intake and carter afb carb (9625s) I have researched the 4 barrel carbs on this forum extensively. General consensus is that you cant beat the stock rochester two barrel. And i agree, they run flawless. And after driving this 4 barrel there are flat spots and hesitation everywhere. Im sure the carb needs some work, but noone gives an opinion about the carter afb. Is it worth rebuilding or ditch it for a different four barrel? I dont want to, but going back to a two barrel is definitly an option iv been entertaining as well

 

Never used one on this engine but did use one on 2 different boat engines and on my old mopar’s.
For those applications they were great, much simpler design than a Holley or Rochester 4 barrel.

 

There are a couple recent threads on the forum talking about these type carbs on dauntless engines. My jeep came to me with the edelbrock 1406 (600 CFM) version on top of a offy intake. While these carbs will get you around town they really are too bug for the 225 cubic inch engine. I really like the MC 2100 carbs with 1.08 venturi size on the dauntless.

 

I had one of the edelbrock performer carbs. They bought out the carter AFB stuff. I put it on my blazer with a 350 and I cannot fully explain how awful that carb was. It got bad milage, poor performance and on washboard roads with a cliff on one side it would flood out my engine which would make me lose PS and PB. I cannot tell you how I would smash that carb with a hammer.

I replaced it with a stock quadrajet and solved every single problem for that engine.

I bought the Holley carb for my V6 225 and its been great for me with mostly on road use. The rochester 2 g my engine originally came with needed a full rebuild and rebush. It was cheaper for me to buy a holly carb and a C/L intake.

 

It's a good carb....for an engine half again as big as your 225

 

I have the same setup. All I can say is they are easy to work on. If your short on money try some of these mods. Might help.

 

I will take the other route. I swapped back from a 4bbl Holley that was great offroad and good on road to a 2 bbl Rochester with a good rebuild that works great for me on and off road. If your engine is stock, I'd prefer the factory 2bbl

 

If you have too large a carburetor for the engine (like an AFB on a 225), fuel control fails because the engine does not pump enough air to make the vacuum you need. You can kinda make a big carb work if you set it up to run rich all the time (avoiding those flat spots you noted), but you'll be throwing away a lot of gas and mpgs will be poor.

There is a 390 Holley 4V that would bolt on, but they are not a great carb for the trail without a lot of mods and added parts. Holley makes a 470 TA that can be a decent option without a lot of changes. There's also a 2V Motorcraft 2100 or 2150 that is said to work well on the 225. You'd need a 4V to 2V adapter, but that's easy to buy or make. These are all covered in older posts if you search. Anything but the original carburetor will need to be tuned to the engine.

The best option is to go EFI.

 

I'm running this carb. Works GREAT off road but has been a challenge to get tuned properly on a 225.

 

This is excellent info thank you. I think i will go back to my stock 2 barrel. At least for now. Id love to leave the offenhauser intake and just use a 2 barrel adapter. Rather then swapping the intakes

 

I have the Edelbrock 1404, the 500 cfm version, on my Dauntless. It came that way. It seems to work well enough, but I had to take it apart and clean it at one point when the engine wouldn't run except with the manual choke nearly full on.

 

Is the intake a dual plane (split into two sections at inlet)? I don't have hesitation driving on the street mine is the 360 dual plane with a carter avs. I also have a 1/2 to 3/4 phenolic riser. I'll check the tag to see if it tells me the jetting.