Fuel Leak and Carb Identification - 2100?

[kjandb]

I thought she was almost road-worthy but noticed a pretty decent fuel lake at the carb. Enough to see a small pool on the intake manifold after a few minutes of idling. Not good. I tightened everything I could and didn't notice any obvious cracks or issues - just seeping out of everywhere.

Looking through the TSM I believe I have a Motorcraft 2100? Does that look right? Was planning on getting this rebuild kit and giving it a shot. I've cleaned a few small-engine carbs but never done anything similar to this. I guess my other option is a cheap chinese carb - or sending it off to get it rebuilt. Any suggestions or tips would be appreciated.

https://www.oreillyauto.com/detail/c/wa ... lk0/15487a

[Stuka]

Going of the back part of the base plate, that is indeed a 2100. The 2150 has a flat edge instead of the curved edge like the 2100 (Visible in the second photo). You also don't have the altitude compensator on the choke like the 2150.

Also, that tag is an original AMC tag. Though unsure if the carb is also original.

Oh, and for a kit, I would suggest getting one from Mike's Carburetors. You can contact them with these photos and the tag and they can find the exact one.

I believe one of these is the one you need:

https://www.carburetor-parts.com/2100-c ... -kit-k4170

https://www.carburetor-parts.com/2100-c ... -kit-k4128

[Srdayflyer]

i would look for a good carb rebuilder, and have it professionally rebuilt, oh yes plenty will tell you its not that hard to, how ever the butterfly shaft i can guaranty that you can wobble the shaft in place, a good carb shop will rebush the shaft holes and fix butterfly float ant all positions especially idle , but hey ive playd with a lot of carbs before being educated on this critical wear point IMO and yes ive used mike's for carb kits, i recommend disconnecting the carb linkage and grab the connection plate and see how much play you have , i spent 150.00 having mine rebuilt and and importantly flow tested and run on and engine so it was completely bolt on ready to go , have since gone f.i. and eliminated all carb issues, carb heat, flooding, vapor lock , cold running (rough),

[letank]

carb rebuilt is not too difficult, I still had my 2100 up to a couple of years ago....

looks like your fuel inlet seat is not cutting off the gas flow, or your float is either leaking or punctured

here is a good overview

https://www.motortrend.com/how-to/rebui ... raft-2100/

in fact in your case you could simply pop off the carb air horn and take a peek.... the 4 top screws after dealing with the choke cam lever

here is another descriptive, a bit different but shows details or both 2100 and 2150, their choke is electric, but a good start!

https://www.therangerstation.com/tech_l ... 0_carb.pdf

poor internet lately, so can't help more today

[tgreese]

Yes, it's a 2100. You have a tag number 1RA2A which should be definitive. The leading "1" indicates 1971, and the "A" indicates an application for an automatic transmission. It's in the 62-73 parts catalog (free to read and download on the Tom COllins site) at Gr 4- C 27. You are perfectly compliant with an original equipment Jeep Wagoneer 2100 from 1971. Looks pristine to me.

Suggest you download and read the parts catalog - it will help you.

If they leak gas, IME it's from the accelerator pump diaphragm. These only last about a year or two when bathed in modern fuel, again IME. NAPA sells a replacement which seems to last ok - much better than the cheaper Dorman equivalent.

https://www.napaonline.com/en/p/CRB24295

[tgreese]

Another observation - I see some streaking on the carb body in the vicinity of the float bowl. These streaks appear to come from the top cover gasket. I would not expect that's the source of your leak ... maybe. the top cover is not under pressure - indeed, the engine will run fine with the top cover of the carburetor removed. This is likely worn gasket and some slosh from the float bowl seeping out the gasketed cover joint.

Feel under the front edge of the float bowl. If the front bottom of the bowl is wet and the sides of the bowl are dry (where the streaking is), the leak is coming from the accelerator pump diaphragm.

I would tighten the top cover and see if the streaked areas stay dry. Don't go Charles Atlas on the four cover screws (42 below), but make them evenly snug on the gasket. Unless you have a grip like Hercules, screwdriver-tight should be fine. The air cleaner bolt also holds the cover down, but go very easy on tightening that - you don't want to bend the top cover.

IME the leaky accelerator pump will drip-drip-drip and leave a small pool of gas in a valley of the intake manifold, near the front of the carburetor. A stuck float will gush gasoline from the bowl vents as fast as the fuel pump can deliver it, and typically stall the engine.

bowlvents.png

There are few places where liquid gasoline can come out and onto the top of the engine. There is the top cover gasket, the accelerator pump diaphragm (33 on Gr 4 - C 27). power valve cover (7) and the inlet fitting (65). Both the top cover and power valve cover use paper gaskets and they typically will not change over time. The accelerator pump diaphragm is rubber and deteriorates.

[kjandb]

Thanks for all the help. Few more newb questions.

1. I didn't have a needle seat gasket previously installed but the kit came with one and the TSM shows one. But the instructions say don't use one if you have a baffle? Not sure what that is?
2. I'm assuming I don't use this spacer? (second Pic)

PXL_20240218_201153315.jpg

Sent from my Pixel 8 using Tapatalk

[tgreese]

1) No baffle. Looks like the old gasket is stuck to the float bowl. If it were a snake, it would have bit you. It's directly under your fingers. Use the new gasket with the new needle and seat.
2) Goes under the aluminum spacer, against the iron manifold. Flat gasket on top of the spacer. Again, the old gasket is in your picture - look more closely. Good time to replace the PCV valve.

Read the parts book (!!!) free to read and download on the Tom COllins site. Gr 4 - C 27. That's your carburetor!! Both those gaskets are shown there.

[candymancan]

Wheb you get it all together put the heater hose on this. I drew and arrow from the hose where it needs to go. This heats up the choke quicker

[kjandb]

Thanks for the help. Got it put back together and it's running so much better. And no more more leaks.

Trying to get it tuned now. Does my carb have a good port to hookup a vacuum gauge? Is the pcv a manifold port?

Sent from my Pixel 8 using Tapatalk

[tgreese]

What's a pcm? You mean PCV?

All the manifold vacuum ports will give the same vacuum signal, just in different locations. Some of the ports at the base of the carburetor are "ported vacuum" and are blocked off at idle. Otherwise they are the same as the manifold ports. I'd look for a port on top of the intake manifold to connect to.

[rocklaurence]

I like the 2150/2100s', they are simple and work. I've rebuilt several [>5] and the ones I've rebuilt came with float rebound springs and needle springs. Which are good for offroad use.