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Carb suggestions for newbie

Carb suggestions for newbie

cavjock22

Jeeper
Posts
18
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Location
Houston Texas
Vehicle(s)
‘81 CJ7, 258 4.2L, Auto Tranny, All original
Gents
I bought an 81 CJ7 with all original equipment. AMC 258 i6 / 4.2l with auto tranny- non quadratech.. Bought it barely running. Would not run longer than 10 sec.. Long enough to get on trailer. I now have it running.
The PO has installed a new tank but failed to vent it. I corrected that along with capping some vacuum lines. Ran good in neighborhood except for not wanting to idle.. Before he sold it he installed a cheap chinese carb- see pic..
It cold starts up good. chock operates correctly. RPMs are about 1900 until tap throttle then she idles to about 1000.. From there I can’t get any less with idle adjustments.. Fresh oil, Fresh plugs. Cap n distributor looks good..
Should I buy a weber carb? Any suggestions?

Also pic of original carb in box?

Im grateful for your help

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I have a Weber 32/36 on my AMC 258 i6 / 4.2l and other than it being touchy to get the idle set right I love it. Once it is set up the engine purrs right along and I get pretty decent mileage for an old engine.
 
I have a Weber 32/36 on my AMC 258 i6 / 4.2l and other than it being touchy to get the idle set right I love it. Once it is set up the engine purrs right along and I get pretty decent mileage for an old engine.

The 32/36 is what my research has found.. Seems pretty straightforward for the install. When you say touchy.. Do you mean 1/2 screw turn changes a lot? Is it pretty straightforward to set? thanks
 
Welcome aboard from Dallas neighbor. do you have vacuum leaks? spray some carb cleaner around outside of carb flange, intake flange and vacuum hoses, any vacuum leaks will suck carb cleaner into motor and idle will speed up

also is it running to lean? put your hand over top of carb to choke off its air supply

check choke linkage to make sure that its fully dis engaging as well

the webers or MC2100 carbs are great carbs
 
The 32/36 is what my research has found.. Seems pretty straightforward for the install. When you say touchy.. Do you mean 1/2 screw turn changes a lot? Is it pretty straightforward to set? thanks

I had to play around with it a little to get it set right. It didn't help that the PO had totally screwed up the settings on idle and lean as well as jury rigged the throttle return so it was not stable.. I downloaded the setting instructions from Redline, zeroed everything out and followed the steps and it works great. It helped that I had my kid sitting in the driver seat telling me what the Tach said as i was adjusting idle, otherwise it would have been a lot of turn a screw, check idle and repeat.
 
Sprayed carb cleaner around the different vacuum lines and carb base and no change on RPM’s.. Think i’ll break down and try the weber carb...
 
Try very soapy water in a spray bottle-You'll see the bubbles get pulled inside.
LG
 
I went with the MC 2100 that comes off a 72 bronco. When I did my research this carburetor what is a good match for the AMC 258 i6 / 4.2l engine and is an easy modification. Of course I’m not finished with my rebuild so I can’t vouch that it’s perfect. Check out my blog in the link below or follow this link for my write up about it

1983 CJ7 Rebuild: MC2100 Carburetor Rebuild Part I (Disassembly)
 
I went with the MC 2100 that comes off a 72 bronco. When I did my research this carburetor what is a good match for the AMC 258 i6 / 4.2l engine and is an easy modification. Of course I’m not finished with my rebuild so I can’t vouch that it’s perfect. Check out my blog in the link below or follow this link for my write up about it

1983 CJ7 Rebuild: MC2100 Carburetor Rebuild Part I (Disassembly)

Man that’s an awesome blog for somebody rebuilding a mc2100.. Good luck with your build..
 
Weber carb should be in today from Amazon... Hoping that fixes my problems...
While waiting, replaced the pressure power steering hose.. It was leaking on the bend close to the exhaust manifold making a mess under the hood. Poor design or PO poor routing??
Dropping the steering box was a bear and getting the hose fitting to thread back was tough also.. But she is fixed now....
 
Weber went on with no problems.
She fired right up and went to a smooth idle out of the box.... No adjustments needed..
Very happy... Got rid of miles of vacuum lines...

If any body would like to buy a carter original carb , a no name carb- ebay (all from PO....). and factory air cleaner assy.. It’s for sale... $125.00 takes it all
See pics

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