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My 1979 CJ5 4.2L has a leaky carb and is fairly rough shape. I am not the best mechanic would it be better to buy a replacement or try a rebuild? I will travel to Iowa to pick it up from my sons place in February.
 

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Carbs can be a bit tricky, the one on there may be wrong, or have wrong parts.

Get a rebuilt replacement so you know you're starting off right. You will have enough sorting out to do without the carb messing you up.

[You may not be willing to spend the bucks right now, but EFI is well worth it if you're planning to keep and use this Jeep]
 

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This is what I would do for a direct replacement,

Install it and tune it correctly.

Cheap enough, I've put many on for other Jeep people, and had no problems.

Prepare for:

other more expensive recommendations and that somehow I'm somehow "Joshing" you.

See post 17 in this link https://www.jeepforum.com/forum/f8/82-cj7-carb-4399321/index2.html

-----JEEPFELLER
 

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Jeepfeller isn't kidding about the "tricky" part; just ask devildog80! MC 2100 I had on my 258, running like a sewing machine, is not overly happy on his 258.

Probably the least expensive option would be to rebuild what you have. Rebuild kits (should) come with instructions, and normally all you need is couple of screwdrivers, needle nose pliers, and some carb cleaner. Follow the instructions, be patient, and you should have a happy carb.

Jeepfeller's route is probably the easiest/most expedient.

I went the Howell EFI route, but I have done a complete frame-off as well as a full engine rebuild.

Pretty much comes down to you picking the option you're most comfortable implementing. :smile:

BTW, you're missing the cowl-to-front clip support bars. Took me a minute to realize they were missing; I kept looking at your pic and thinking "this looks too clean!"

One other thing ... keep an eye on your oil for metal particulates. I noticed the HEI distributor. When I did my engine rebuild, I found evidence proving some information I ran across that the drive gears on HEI dizzies can chew up the cam gear on older engines. You won't see metal shavings, per se, but if you put a neodymium magnet in the bottom of the oil pan, it will catch a lot of the super-fine particulates.
 

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A rebuild of the carb ie really easy and inexpensive . Think of it more as a thorough cleaning than a technical rebuild. Just follow the instructions to the letter and don’t loose any of the small pieces. It will run just fine with the BBD on road. If you want it to run in the cold, you are going to want to put the air cleaner back on and the heat chimney on the exhaust manifold. I would also recommend, although not required, reconnecting the evap system to control the smell of gas. Double check the the fuel return on the filter is oriented at the 12 O’Clock position.

Fuel injection is certainly an option the will improve how it runs, particularly when cold and when off angle, but it isn’t cheap nor is it necessary.


Sent from my iPad using Tapatalk
 

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A rebuild of the carb ie really easy and inexpensive.
I second this, I'm a complete newb and I successfully rebuilt my Carter BBD with the $25 rebuild kit from Amazon. (Same one that Oreillys Carries. )
 

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It is hard to diagnose in Florida when the Jeep is in Iowa. I assume you aren't going to drive it home from there so wait until you get to its retirement home in Florida before worrying about it. I have 45* #2 Phillips that I use every spring to snug the top half of the carb to the bottom half. That stopped the annual leak until it didn't. The gasket between the top and bottom tends to dry out/shrink during periods of inactivity. A mal adjusted automatic choke or a manual choke can cause problems too. I think without an air cleaner we can rule out a clogged air cleaner.
 

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My 1979 CJ5 4.2L has a leaky carb and is fairly rough shape. I am not the best mechanic would it be better to buy a replacement or try a rebuild? I will travel to Iowa to pick it up from my sons place in February.
Unless you are trained in rebuilding a carburetor I wouldn't do very much to it. If it's leaking gas externally it's probably the float or seat pin. I wouldn't do any more than replace the pin and adjust the float. That is simple enough and it will either work or continue to leak where you would need to adjust the float more.
 

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Discussion Starter · #11 ·
new to jeeps, Thanks for the info

I am not buying anything yet. My son is a mechanic and is compiling a detailed "to do" list for me while it is setting in his garage. I will trailer the jeep back here before I start investing in parts. I plan to pull the body with a little help from my friends (I have friends with skills). I am just excited to join the jeep owners family. Thanks again
 

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Work with your budget, and build your Jeep the way you want it.
As for carb rebuild, relatively simple, and perhaps your son can do that now for you. Takes about an hour, then you will know if replacement is needed, or if existing will work with rebuild.

My situation, had a Solex carb when I bought my '81 CJ5 in 2019, and I was able to drive it. Past that, there was no performance to be had, and really poor on any acceleration. Had to feather the gas pedal all the time while driving. Idle was good, it ran, but.....never went on any major roads, top speed was about 50 for a mile or so, then onto the trails. Shifted to 4 low, and was enough umph to do what I wanted, and get back home. Thats all I got to say about that!
Then Mongo228 was selling his rebuilt MC 2100, so read up on pro's/con's and went by his place one day, and we switched carbs. Been trouble shooting it since, as it worked great on his '79-80 258, but like he said, does not like mine for some reason. We suspect emissions I have on my engine that he did not, but working on the solution.
I will not let this carb beat me, it will work, and as bad as it runs....a big improvement over the Solex!
Good luck, and have fun with your new project :)
 

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I recommend against a kit, partly because it can be trickier than it looks without the special gages, but moreso because you don't know the history of this one. Whether it's even the correct one (as opposed to a similar one for use on another car), or if someone along the way lost parts or used incorrect parts.

You will have enough of an issue tracking down problems, it's really to your advantage to know the carb is right so you can attend to other areas.
 

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I have rebuilt a number of Carter BBD and they are a bit fiddly but doable. The parts kit is $15 to $20, buy the one with the accelerator pump plunger. They come with detailed instructions. Buy several cans of carb cleaner and a plastic basin larger than the carb.

Take the carb off and settle down at an empty table with newspaper over it. Put carb in tub, take the linkages off, take the 6 screws out of the top and take it apart. Take out the inlet valve assembly and the idle tubes. It is pretty much apart now, so you can start cleaning.

WHEN YOU TURN IT UPSIDE DOWN 2 SMALL BALLS WILL DROP OUT. KEEP IT IN THE BASIN!!!

You can now clean all the parts with the carb cleaner and a small brush. There will be a lot of dirt!

When you open the parts box you will see there are multiple gaskets, covering different versions over the years.

Depending on where it was leaking you may start with just flushing through the internal passages with the carb cleaner.

Then put the idle tubes back together with new gaskets.

Fit the new inlet valve.

Set up the float height, instructions will tell you how.

New gaskets. New accelator plunger. Can be fiddly.

Lower the top back on, get the metering needle into the hole properly. 6 screws back in.

Now set up the metering needle and the accelerator pump as per the instructions.

Set up the choke and reinstall linkages.

Put back on vehicle. Adjust curb idle and idle mixture. Set up choke mechanism.

They take less than an hour to clean but work so much better. If you have the new inlet valve, adjusted the float properly and fitted new gaskets it will not leak anymore.


This is a routine service operation, preferably less than 5 years between carb services. If your Jeep sits for long periods the fuel can evaporate and leave a residue that clogs it up.

An upgrade is to drill the idle tubes a little larger, less likely to clog.


Nothing wrong with a BBD!!

If you want a new one, the Weber 38 is hard to beat.
 

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You will get many opinions on the OEM Carter BBD carb. Fuel injection is nice, but comes at a premium cost compared to a carb kit ($25.95). The rebuild/cleaning is actually not that hard. Take lots of pictures as you go and take your time. Once you get over the inevitable "small parts fear," you will be fine. Keep parts organized and follow the instructions. I've had good luck with Mike's Carburetors.

Here is a ink to the carb kit you will need for the 1979:
https://www.carburetor-parts.com/bbd-k4319.html

You can review the instructions in advance here:
https://www.carburetor-parts.com/assets/instructionsheets/k4319.pdf

If you find you need to replace parts, he has many here:
https://www.carburetor-parts.com/bbdparts.html

I have rebuilt many BBDs over the years and your 1979 Carter BBD is actually a desirable carb. It pre-dates many of the emission issues. It is a non-feedback carb without the stepper motor. These are old, and like any old part it needs cleaning. If you don't want it anymore, please let me know.
 

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I would do a visual inspection first. If the throttle opening is worn, this could cause a vacuum leak and mess with your mixture and power settings.
There is not much you can do but ream it out and in a bearing for the throttle shaft.

It's real critical to keep the bearing sleeves straight. There is a tool you can buy for doing this.

That's why buying a new carb might be better than rebuilding an old one.
 

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I have an air cleaner assembly from an 85 Cj7 258 that I'd like to get rid of. Also I have a brand new rebuilt Carter BBD with stepper motor for same engine that is still in the box. I also have a Carter BBD that could be rebuilt. If anyone is interested, let me know.



Mark
 

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I would do a visual inspection first. If the throttle opening is worn, this could cause a vacuum leak and mess with your mixture and power settings.
There is not much you can do but ream it out and in a bearing for the throttle shaft.

It's real critical to keep the bearing sleeves straight. There is a tool you can buy for doing this.

That's why buying a new carb might be better than rebuilding an old one.
I used brass tubing from Ace Hardware to bush my throttle shaft.
 
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