Carburetor Replacement 1974 258

Anyone have information on carburetor replacement for 1974 Jeep CJ5 with a 258. Everything is factory. I am switched to and electronic ignition. Looking to replace Carter YF single barrel carb. Have a standard intake for the single barrel carb. Not looking to rebuild or switch to EFI. Looking to switch carb to either a Weber, Holley, Motorcraft or other. Would like to get an idea of best choice that would be least complicated to maintain and boost HP. Thanks for your help.

 

You going to switch to a 2V manifold too?

 

The MC 2100/2150 is a hard to beat carburetor. Simple to work on and just about any auto parts supplier has rebuild kits in stock.

 

Replaced the intake a few years ago. Would like to utilize if I can. What intake would you recommend? How much do you think for a new intake?

 

Well, my J10 has manifolds from a '85 CJ-5, and a 2100. The factory manifolds from 1981 forward are pretty good, supposedly. Putting a 2V carb on a 1v manifold seems kind of pointless.

 

FWIW, I have the fake Weber 34/34 on my 73 258 with the original 1 bbl intake manifold. The carb came in a kit with an adapter for the intake and all the proper linkage. It runs quite good. I really can't tell if there is any HP or mileage gains and suspect if there were any it would be quite negligible.

 

Without a manifold swap, you may as well keep the YF, IMO. There's nothing wrong with the YF as a carburetor. If you are unhappy with how your YF works, a professional rebuild with the right parts should fix you up. The F134 guys on the Early CJ-5 forum have a lot of experience with the YF, and could advise you on where to send your carburetor.

If you want to go to a different carburetor just for the sake of something different, the Redline Weber kit works pretty well, from what I gather. I think this is your only option for an actual new carburetor. Avoid the Holley 2Vs unless you are willing to do a lot of research and modification, or you never go off the pavement (you'll still need to tune the carburetor).

Unless you live in California, carbureted vehicles are pretty scarce in the yards, and I think it's unlikely you will find a used 2100 except from an online seller. This guy http://www.ebay.com/itm/221981624163#rwid has been selling the Motorcraft kits for a long time, and gets good reviews. The 2100/2150s are great carburetors, but you'll need to be savvy re carburetor rebuilding, setup and tuning to make a junkyard carb work for you.

 

i agree re: manifold swap. i have a weber 2bbl on the 1-v manifold, and though it works excellent, the yf performed no worse. i was chasing idle issues that were the fault of the prestolite ignition, not the carb. once i installed a chevy hei w/buick cap, the idle problem disappeared, and the jeep has run great ever since (10 years). could have avoided the expense of the weber had i correctly diagnosed the poor idle culprit. that said, i'm not disappointed with the weber.

 

Can I pair and Offenhauser square intake with a mc2150? I might consider replacing the intake. I was mistaken in mu last post, I replaced the exhaust manifold a few years ago. Can I get an Offy to work with my 74 258?

 

An offenhauser will work but you're going to need a carburetor adapter.

 

You realize that the '81-up factory aluminum manifold is a 2V manifold? The Weber will bolt to it without an adapter, and the Motorcraft needs an adapter. The Offy intake is for a 4V. You could run the Offy manifold with a 21xx, but you'd need to reduce the bolt pattern to the Holley 2V pattern with an adapter. Or, you could run the Holley 0-8007 390 CFM 4V carb which will bolt directly to that manifold, but it will be far from a drop-on deal (in terms of tuning), and you'll need to solve the Holley's terrible off-pavement performance if you want to take this Jeep on the trail.

Just a comment - I think you are ill advised to spend a lot of money on speed equipment for the 258. Swapping in a 4.0L is a very popular and cost-effective solution, and will give you way more bang-to-the-buck than aftermarket speed parts on the 258. You can use the excellent Mopar multiport EFI that comes with the 4.0L, and get a significant improvement in both power and economy without any speed parts. And, if that's not for you, there are a lot of upgrades for the 258 using junkyard parts that will be a lot more cost effective than expensive aftermarket parts.

 

Thanks for the advice. Not looking to put speed parts on. Just looking to upgrade the carb to something a little more reliable. M7ne seems to need to be replaced. Was thinking to rebuild, but would rather dump this ebay putchased card I'm running now. Would like to upgrade to a 2 port intake. Any issues with bolting a smog era 2v manifold to my non smog 1974 258? A Weber would bolt right to it, any particular model weber I should look for?

 

The later manifolds bolt on. For my '77 J10, I had to notch the power steering bracket slightly, but otherwise it's a bolt-on. You have to use the matching exhaust manifold. The newer intake will not work with the older exhaust, and vice-versa. Get the BBD throttle linkage (bell crank on the engine), air cleaner, tube between the manifolds (for EGR), and any other bits that look useful.

If you buy a Weber, you want the kit from Redline. This is what is meant by "Weber." http://www.redlineweber.com/carb-kits/auto/jeep/ These kits are sold by many Jeep retailers. With the 2V manifold, you want the kit to replace the Carter BBD. Be sure to get the carburetor linkage from the manifold donor.