Engine Engine Stalls on Rocky Inclines

[mjclimber]

Hello,
I just joined this forum and I'm looking forward to sharing and learning from you all. I acquired a '75 CJ5 with a AMC 258 i6 / 4.2l , 3 speed manual about 18 months ago. It has 105K miles and runs good for a 50-year-old original jeep. However, if I try to climb a fairly rocky 4WD trail, it will flood out as soon as the jeep hits a moderate pitch angle. I believe this is a problem with carbureted engines, but I suspect it should handle a 4WD trail a little better.
It has a AMC 258 i6 / 4.2l with a Weber 1 barrel, and I fuel is spilling over the bowl in a pitch situation. In addition, it seems the AMC 258 i6 / 4.2l is a little low on power (although it's improved after adjusting the ignition timing).
I've read some threads on this problem where people recommend a MC 2100 carb, which is a 2 bbl, and I have a 1bbl manifold. So, my dilemma is whether to change the intake to a 2bbl and go with the MC 2100 or to try a 2bbl to 1bbl adaptor plate.
It appears the exhaust manifold is bolted to the intake manifold and I'm having trouble finding an intake manifold that will fit, without changing the exhaust manifold.
Does anyone know what the original stock carburetor was? I think my current Weber was added at some point.
Just looking for any similar experiences or recommendations from the group.
Thanks very much!
MJ

 

[mjclimber]

Here's a picture of the original adapter and the gasket for the 2100 adapter plate. My new 2100 adapter plate fits the MC 2100 carb but will not align with the adapter bolts holes on the intake.

 

[Manic Mechanic]

What's under that plate? Is your manifold cast iron or aluminum?

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[mjclimber]

What's under that plate?

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The plate in the picture bolts to the intake. There are 2 bolts that are 2 and 15/16 inches apart center to center. The second picture shows the gasket for my new adapter plate and how it doesn't align with the existing plate.
Thanks!

 

[mjclimber]

The plate in the picture bolts to the intake. There are 2 bolts that are 2 and 15/16 inches apart center to center. The second picture shows the gasket for my new adapter plate and how it doesn't align with the existing plate.
Thanks!

If the Mr. Gasket plate has bolt holes with 3 and 1/4 inches center to center and fits the MC 2100, then that would work. But I don't see any dimensions on the link.

 

[Manic Mechanic]

https://www.amazon.com/Trans-Dapt-2025-Carburetor-Adapter/dp/B000N8GTL8/ref=asc_df_B000N8GTL8/?tag=hyprod-20&linkCode=df0&hvadid=693349724121&hvpos=&hvnetw=g&hvrand=5735548903762266984&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9061285&hvtargid=pla-571138004121&psc=1&mcid=6d40de41c4ee3e11afdc377f1ea21ef1&gad_source=1

Amazon.com

You might need one of these. I was thinking you had a newer intake. (Hence the first link above) Without seeing it without the adapter it's hard to say for sure. Either way you will want to do away with the current adapter.

These should fit this style intake.

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[mjclimber]

Awesome! I did some checking on the bolt pattern and it appears the Transmission Dapt 2041 should fit the intake and carb. Thank you!

 

[Manic Mechanic]

Your welcome

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[73CJ]

Here’s the stock setup two barrel on a two barrel manifold with stock exhaust
Just sitting in my parts shed
Weighs a ton Shipping would kill any deal
You anywhere near Fargo, ND?

 

[mjclimber]

Here’s the stock setup two barrel on a two barrel manifold with stock exhaust
Just sitting in my parts shed
Weighs a ton Shipping would kill any deal
You anywhere near Fargo, ND?

View attachment 101870

View attachment 101871

Thanks for the info...
I'm in central Colorado. I did find an adapter plate (ordered) which will hopefully fit my 1 barrel intake and accommodate the MC 2100 carb.
I think a 2 barrel intake would be a better solution though. What would want for the intake? I assume the Motorcraft 2100 carb will fit this intake, correct?

I'm also looking for a stock air cleaner assembly if you happen to have one...
Thanks!

 

[NP435]

Thanks for the info! I checked on the Dead Jeep Parts website but the site isn't working well (maybe I'm on the wrong site?) If you have a ph. number or link, that would be great.
Thanks!!

1-401 642 0236

 

[NP435]

Thanks for the info...
I'm in central Colorado. I did find an adapter plate (ordered) which will hopefully fit my 1 barrel intake and accommodate the MC 2100 carb.
I think a 2 barrel intake would be a better solution though. What would want for the intake? I assume the Motorcraft 2100 carb will fit this intake, correct?

I'm also looking for a stock air cleaner assembly if you happen to have one...
Thanks!

I had a custom adapter plate made locally. Not sure if the factory air cleaner fits the 2100/2150 family. I use a open element filter along with a foam prefilter obtained from a Kholer lawn mower filter.

 

[Manic Mechanic]

Updates? Running well?

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[mjclimber]

My apologies for the much delayed update. After quite a bit of searching around, I found a carb adapter plate for the stock manifold and installed a MC 2165 carb. This made a huge improvement and the jeep handles rocky inclines and off camber situations without stalling. Thank you everyone for the good recommendations.
MJ

 

[CJ]

My apologies for the much delayed update. After quite a bit of searching around, I found a carb adapter plate for the stock manifold and installed a MC 2165 carb. This made a huge improvement and the jeep handles rocky inclines and off camber situations without stalling. Thank you everyone for the good recommendations.
MJ

Great to hear the MC worked out for you?

 

[Belizean]

My apologies for the much delayed update. After quite a bit of searching around, I found a carb adapter plate for the stock manifold and installed a MC 2165 carb. This made a huge improvement and the jeep handles rocky inclines and off camber situations without stalling. Thank you everyone for the good recommendations.
MJ

Is it an updated 2100 ?

 

[mjclimber]

Is it an updated 2100 ?

Yes, actually it is the MC 2100. Works great on the AMC 258 i6 / 4.2l .