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Getting ready to install a completely rebuilt 2100.The motor currently has the carter BBD. The motor and carb are running well as is. (But I want to upgrade). I'm hoping since this is the case it will be an easy swap and fine tune. If Anyone has advice or tips on installing and tuning this set up, it would be most helpful.
(elev. 5500+)
When I started his Jeep to move it in the shop it started right up just fine.
First thing I noticed was a high idle.
I turned the idle screw down to 700 rpm (factory specs).
Then the ugly came out, engine was shaking and missing.
Put a vacuum gauge on it and the engine was only running 15" (at sea level).
I figured it wasn't a big deal as I planned to install a new carb base/gasket and remove all vacuum hoses except the PCV and vac advance.
After completing this I only gained 2" vacuum (17")
Checked the intake manifold, no leaks.
Checked the timing and it was 4° retarded (technically - 2° out of specs).
Set the timing to 6° not much of an improvement just a tick over 17" and it still had a miss (typically sea level would be 19-21").
Turned out to be a burnt exhaust valve.
Who knows how long it ran retarded, since before my buddy owned it for the last three years.
Running retarded heated up the valves, running the high idle masked the vacuum leaks and burnt valve.
A slower idle exposes a burnt valve, a faster traveling piston will help recover a leak.
Fact is he always thought the engine ran fine, without any issues, and told me as much.
I'm mentioning this because the carb should be the last thing anyone should adjust when the engine isn't running good or your contemplating a switch to a new carb or FI.
My advice would be make certain all aspects of your engine is working as it should and within factory specs.
Also, if you have no use for your stock carb you can remove part of the linkage and swap it over to the 2100, it worked perfect for me.
I did have to heat and straighten the piece and drill a couple of holes to attach it, easy and perfect fit.
Check your jets, you may want 46s or 47s in your area.
Posi, thank you for your experience. Hopefully I won't have any of those problems. I did a complete rebuild less then 8,000 ago. (but you never know!) My thinking is, if I install this carb and all of a sudden my Jeep is running like . I should be able to narrow it down to the carb. From what I read so far it seems like vacuum leaks are the #1 problem do to the gaskets and adapter plate used. THANKS FOR THE HEADS UP ABOUT THE LINKAGE. I did not know that. also I'm running 45 1/2 jets. The elev. out here is a real pain in the ...
Getting ready to install a completely rebuilt 2100.The motor currently has the carter BBD. The motor and carb are running well as is. (But I want to upgrade). I'm hoping since this is the case it will be an easy swap and fine tune. If Anyone has advice or tips on installing and tuning this set up, it would be most helpful.
(elev. 5500+)
You're only upgrading to a more user friendly carburetor. Switching from one carburetor to another really isn't an "upgrade" as you're still going to have the same carbureted engine problems, just with a different carburetor.
Do you have the correct adapter? As Posi mentioned, the linkage is different, a BBD is a pull down carburetor, the 2100 is a pull back, like a Holley. Have you measured your throttle cable, it may not be long enough. Have you researched were all of the vacuum lines are going to go? Are you going to plug some stuff off, are you still running an EGR and PCV valve, what are you going to do with the CTO switch? What are you going to do with the charcoal canister? I had to figure out all of these things when I switched to a MC2100, then when I put on a Holley 390cfm 4bbl, and then again when I went back to a MC2100.
Swapping from one brand to a different brand is not a half an hour thing, there are a lot of differences between the two brands, and your AMC was set up for a BBD, if you don't have all of your contingencies laid out, you're going to spend hours and hours tracking down little oh by the ways and **** that you forget.
In the end, the Motorcraft is a much better performing carburetor than the BBD, but you're not really upgrading, fuel injection is upgraded, you're just swapping out one set of problems for another.
You're only upgrading to a more user friendly carburetor. Switching from one carburetor to another really isn't an "upgrade" as you're still going to have the same carbureted engine problems, just with a different carburetor.
Do you have the correct adapter? As Posi mentioned, the linkage is different, a BBD is a pull down carburetor, the 2100 is a pull back, like a Holley. Have you measured your throttle cable, it may not be long enough. Have you researched were all of the vacuum lines are going to go? Are you going to plug some stuff off, are you still running an EGR and PCV valve, what are you going to do with the CTO switch? What are you going to do with the charcoal canister? I had to figure out all of these things when I switched to a MC2100, then when I put on a Holley 390cfm 4bbl, and then again when I went back to a MC2100.
Swapping from one brand to a different brand is not a half an hour thing, there are a lot of differences between the two brands, and your AMC was set up for a BBD, if you don't have all of your contingencies laid out, you're going to spend hours and hours tracking down little oh by the ways and **** that you forget.
In the end, the Motorcraft is a much better performing carburetor than the BBD, but you're not really upgrading, fuel injection is upgraded, you're just swapping out one set of problems for another.
So what your saying is, it's an upgrade but not really an upgrade. Maybe I need to edit my post to say "changing to a better performing carburetor, not upgrading" I'm glad you set me straight on that because I thought this "upgrade" was going to give me 500 more horsepower and 50 MPG.
Getting ready to install a completely rebuilt 2100.The motor currently has the carter BBD. The motor and carb are running well as is. (But I want to upgrade). I'm hoping since this is the case it will be an easy swap and fine tune. If Anyone has advice or tips on installing and tuning this set up, it would be most helpful.
(elev. 5500+)
So what your saying is, it's an upgrade but not really an upgrade. Maybe I need to edit my post to say "changing to a better performing carburetor, not upgrading" I'm glad you set me straight on that because I thought this "upgrade" was going to give me 500 more horsepower and 50 MPG.
You do understand that it's not as simple as bolting on a different carburetor right? You're not swapping out a Holley for the old Edelbrock on a SBC, right? You do understand that your "completely rebuilt" Motorcraft carb that you probably bought on eBay wasn't "professionally" rebuilt? That it's a used carburetor, probably from the '60s or '70's that very few places carry parts for and that even less people understand how to properly tune if you can't figure it out?
There are people, on this forum, that believe that a properly tuned BBD is just as good as an MC2100. There are people, on this forum, that will tell you that the only way to go is with a Weber...
All I was saying is that you're not really upgrading swapping out one carburetor for another. You're trading out one set of problems for another one. IMHO is the MC2100 a better carburetor, yes. I've spent tons of time researching the Autolite and Motorcraft series carburetors, and have fiddled with the 4 different ones that I've owned over the past decade on my own CJ. Learning how they work, what it likes and what it doesn't.
Your right, sorry for my smart A** reply. I should have giving more info in the first place. You sound like the person that could help me with any tuning problems I may have when I get it installed. Here are a few things you should know.
1. HEI ignition
2. No emissions. (vac adv. & PCV only)
3. Have adapter plate and all gaskets.
4. throttle cable is long enough. (and have seen multiple linkage set-ups so have a few ideas)
5. I feel comfortable with the instillation and getting it to the point of running.
I think what I need most is someone like you who has set one up and can help me find the sweet spot when I do get it running. I know the attitude is higher here then there, but you still have more experience with these carbs. If were to have one of those weird can't get it to run right problems. I hope you're still willing to help me.
Yeah man, that's what this place is for is helping each other out
So, the 2 biggest problems I initially had were figuring out how to work the the throttle cable. The BBD is a pull down, the motorcraft is pull back.
Here's the throttle linkage for a YF and a BBD
Here's a pic of what someone came up with. You're going to have to figure out the throttle cable, and return springs.
I used something like this;
And I made a homemade bracket for the return springs.
The next thing is the vacuum lines. If you're only running a PCV valve your vacuum lines should be pretty simple. I would suggest you go to your local auto parts store and get one of the 20 packs of vacuum caps, and cap everything you're not using. I found this diagram online;
You would just need to cap off the lines for the CTO and EGR.
I made this diagram, it's a lot simpler;
These are some good starting points. After getting it set up, then you can start dialing it in.
Here's a couple of places that I know of that sell Motorcraft/Autolite 2100 series carb parts;
Mike is a good dude I've got three carburetors from him All three bolted write-up With the little rigging But out of the box they needed very very fine adjustments mainly the choke and timing.
I have noticed That the carburetor isn't as good On a 1 barrel intake My 77 And my 86 Both head 2 Barrel intakes But my 76 has stock one barrel It runs great But I can feel It has more to give But without the volumetric efficiency of a 2 barrel intakeI've realized it is what it is..
Mike is a good dude I've got three carburetors from him All three bolted write-up With the little rigging But out of the box they needed very very fine adjustments mainly the choke and timing.
I have noticed That the carburetor isn't as good On a 1 barrel intake My 77 And my 86 Both head 2 Barrel intakes But my 76 has stock one barrel It runs great But I can feel It has more to give But without the volumetric efficiency of a 2 barrel intakeI've realized it is what it is..
. I should be able to narrow it down to the carb. From what I read so far it seems like vacuum leaks are the #1 problem do to the gaskets and adapter plate used. THANKS FOR THE HEADS UP ABOUT THE LINKAGE. I did not know that. also I'm running 45 1/2 jets. The elev. out here is a real pain in the ...
