I do have a yj, but figured the cj guys would have some more info for me.
I recently swapped out my carter for a mc2100. I've checked and double checked for leaks, set and reset my timing and tried every combination of vacuum setups.
the issue i'm having is a severe dead spot at about quarter throttle and 12-15 hundred rpm. especially going uphill. as soon as i hit the throttle i get a slight surge it starts to pick up and then it flattens out, Like i have no power and then it coughs... if i don't let off the gas, it will just die. I can also push in the clutch gas it and feather it out... This is my daily driver, and i've been riding the clutch on hills and off the line for about 2 weeks now. I would like to not have to replace the clutch and was hoping you guys could provide a little insight. I'm idling at a little over 500 rpms and even increasing idle speed doesnt sort it out.
You left out a lot of info with your question.
Ok did you overhaul the carb before you installed it?
Have you checked to see if you have sufficient fuel supply to the carb? Fuel line plugged? Fuel Pump Weak or bad, is the filter plugged.
If you put this carb on with out an overhauling it chances are it could be all gummed up inside. If it is the carb it sounds like you are not transitioning off your idle cirquit to the main cirquit well, or not at all. There are a few things at play here. One to properly transition from idle to the main cirquit your accellerator pump shoots a little extra fuel into the engine. If that is working then you may have a bad power valve.
You stated you have already checked for leaks and I assume you mean Vacuum.
yeah, sorry... I bought this carb off the guy from ebay. supposedly he tears em apart cleans them to just about factory spec. i can say that it was definitely new looking when i got it. all brass fittings nice and shiny, new float new jets power valve at least from outside looks like its probably new.
that's exactly what i was thinking. it seems like it's just having a hard time transitioning from idle to main. even if i gas it up real slowly the jeep tends to bog and surge and bog and surge before coughing. occasionally after the cough if i floor the gas pedal it'll pick up chirp and i'll be off. only to face the same problem in the following gear.
I'm considering the fact that i'll have to rebuild this carb again. I'm okay with this but i'm lost as to which rebuild kit i should get.
there is no tag on this carb so i have no idea where or what it came from or what rebuild to use for this application.
no vacuum leaks. this thing is on tight. new hoses new gaskets i went really overboard the second time around because i figured initially this was likely a vacuum leak issue.
Was this jeep running half way decent before the swap?
Check for good fuel supply. OH and if you are running the bypass style filter I would plug the Bypass to ensure proper fuel pressure to the carb.
I would start the thing and let it warm up then adjust the two idle air screws all the way in then back out 1.5 turns before you start it, then adjust for best idle. Turn in till idles rough then back out till idles smooth do both sides. I would then pull the top off the carb and see if there is any fuel in the bowl. Then I would check and measure the float and make sure it is adjusted correctly. If non of this fixes the problem complete tear down and overhaul again. Not sure what to tell you about how to go about getting kit. THe date of manufacure of the carb should be etched into the bottom of the carb which will get you close.
yeah' I've done all the above, I finally got it running great right before I did the swap.. New ignition new plugs and wires new timing chain and gears new exhaust new cat. Great compression through all cylinders. I did the swap cause the carter ran a little rich And my mileage was suffering plus from what I've heard you get better mileage and more power. I'll check the bottom of the unit. Some things I've read say that the rebuild kit is universal but somehow I doubt that
I just put a 2100 on my jeep this morning. I overhauled it myself. Runs great. Idles a little fast 1000 rpm but is smooth as butter. Didn't get a chance to test drive it as I have to hook up the throttle linkage, PCV line, and get an air filter for it.
Do you have a ford carb base/spacer under your carb?
If not it can cause a vacuum leak underthe carb.
The base/spacer should have a large vacuum port on the back side of it to run the pcv, and will be about an inch thick. I used the existing vacuum port on the intake to run the brake booster.
I would turn the idle air screws all the way in; then back them out 2-3 turns.
I have probably told you some of this before.
Check to see if you have fuel to the carb by stroking the throttle while looking down into the carb.
Have you contacted the seller to see if he has any ideas? I bought one for my YJ and right out of the box it ran great. Before you tear into it I sure would send him and email letting him know about the problems.
I did... The guy wasn't any help... He gave me a couple Ares to troubleshoot that I had already taken care of and then just left me hanging
So I left neg feedback and now have no way of knowing what marrow carb or which rebuild I should use. If you could ask him what rebuild kit to use that would be awesome as he will no longer respond to my emails
The adapters are hell to get sealed. Had to take mine off 4 times!
If it caughs under load and it idles high! VAC leak.
People swear they don't have any but eventually they find them.
Is your carb a 1.08 mc2100?
If its bigger than that it is too much CFM for your engine!
I had to re-jet mine to 44's from the 48's!
Is your dist dvance on the ported vac or manifold vac? should be on the ported port on the front of the carb or the one on the side under the choke.
Also your choke has a vac port in it for manifold air temp. Did you plug it?