Need Carb help

Just got my Dauntless in about a month ago and love it but I'm having trouble with the 2G carb.
The motor runs rich (sooty plugs and tailpipe smells like gas) and at Cruising speeds wants to cut out randomly. When I trail ride at the lower RPM's I have no problems but when I hit the highway, the problem starts at about 45 mph. It seems to be worst when the engine is cold and really increases with the engine speed.
Adjusting the mixture screws doesn't really make any difference unless I screw them all the way in and then the engine stalls.
I have rebuilt the carb, took it back apart and cleaned it about 4 times, tried changing the timing, completely rebuilt the HEI dist.(cap,wires,rotor,module,coil) and checked everywhere for vacume leaks.
I really feel this is a carb problem and am willing to replace it if enough of you guys agree. If I can find one.

Any help will be greatly appreciated, this thing is driving me nuts mehh

 

Take a compression test then put a vacuum gauge on it. Let us know what your readings are. I have some ideas but no use talking in the wind without more info of engine stats.

 

Compression is around 120 lbs on all cylinders and the vacume is 18 no matter how I adjust the carb.

Any ideas?

 

Your idle has to be around 550-650 to adjust the two fast/slow idle adjust screws. Any thing above idle and the screws are out of the circuit.

 

what is the condition of your fuel pump?

 

Fuel pump is brand new and I added a fuel regulator and guage.
I've adjusted the pressure from 2-5 lbs and can't tell much difference.

 

I can't remember on the Rochester, but the Carter single barrel has a high speed needle that has to be set at the right height or it is too rich/lean. Does the Rochester have a similar set-up and if so is it adjusted right? If I understand it right the low speed circuit is also involved as the carb is opened too-not just at idle.

Adjusting the low speed needles is thus:

Both needles turned clockwise till the seat-carefully-then ccw 1-1/2 turns. Disconnect and plug vacuum to distributor.
Adjust curb idle speed per FSM.
Turn out both needles the same number of turns, ccw, and always make sure the needles are synchronized with each other.
Adjust till max vacuum is attained.
Continue ccw till vacuum starts to decrease.
Turn needles cw 1/2 turns.

This is what I've read anyway. Good luck

 

using a vacum guage and sitting for the highest vacum can cause hesitation. your engine must be @ full operating temp. or you CAN NOT adjust the idle.by popular belief, the idle mixture screws DO NOT adjust mixture,this is controlled by the idle tubes & idle bleeds. the idle screws control the volume of the present mixture. what you need is a steady idle W/ mixture screws 3/4 turn to 1 1/2 (oneand one half) from seated and about .020 clearance from the throttle to the throttle bore.

 

OK, this makes sense but what if the screws are at the position you suggest and the throttle clearance is correct? Where should I look next for my hesitation? Also, how do I get it to stop running rich?

 

first,did you do a major or just a repair carb kit-- either or, did you replace every thing with the new parts? did you completly remove all the FM on the carb. soak each part in a strong carb. cleaner? rinse W/H20 or mineral spirits? blow all parts out w/comressed air? did you make sure your venturi passages were clear paying note to your jets? install it back in order and pay attention to the screw tightening order? and you are for sure your carb. is the right number for your engine. we will start from here, and we will get this going for you. are you running headers? this makes a world of difference if you are.

 

ok, i guess my last post was'nt what you for ask for. HESTITION, the duration spring , if old & weak, will result in slow fuel discharge causing hestition. if you did not orientate the duration spring cap correctly, the spring will be under the wrong pessure. if the float level is high, fuel will flow freely from your discharge tube causing a overly rich mixture, opposed to low fuel bowl- which will affect air/fuel ratio .

 

ok,i guess my last post was'ntwhat you were looking for. HESTITATION, the duration spring- if you did not replace it, if it's old it's weak- to little spring pressure results in slow fuel= hestitation. if you did not orientate thr duration spring cap correctly, the spring will be under the wrong pressure. if your float level is high ,fuel will flow from your discharge tube, causing a rich mixture-- opposed to a low fuel bowl affecting air/fuel ratio

 

sorry for the double post, thought the first one didn't enter

 

Today i'm going to order another rebuild kit and every part I can come up with for this carb. (if I can find the part numbers) I will clean everything again and give that a try. If this doesn't work, I guess I'll try a new carb.
Just seems like a vacuum leak inside the carb but I have checked everything out to the point that my gaskets are now shot.
As for this being the correct carb, I believe it is because the PO was using it with no problems untill it set for a few years, but I can't be 100% sure because it has no numbers on it.

 

when you have your carb. apart check all your mating surfaces for warpage before going forward. use a good straigth edge. more than likey your carb. is the right one, your should have had a triangle shaped tag w/ the serial number stamped into it and afixed to one of the top screws on the carb. check W/ the PO and see if he has this tag or remembers the carb. #. the later carbs. had the serial # rolled in the passenger side of the unit. see what you can find out and get back w/me. i have a sourse that custom makes gaskets,duration springs,idle screws,etc. for the correct serial # of your carb. it's important to have the correct gaskets, many rebuild kits come w/ a wide range of gaskets which may not be right for yours. its possible you have a gasket that is covering some passages in your carb. or the wrong thickness gasket.

 

Thanks,
I'll check all of that. Right now I am waiting for the kit and other parts to come in at my local NAPA store.
They said that they could only find one kit and that it was clear on the other side of the country. My parts man said that this may mean that Napa is no longer going to handle this kit.
Wish there was some kind of replacement carb that does as good as the 2g offroad.

 

I suggest that you first identify your Rochester 2 jet carburetor.
You will also need to identify the year of your engine and if it is or was equipped with an exhaust emission air pump.

If the aluminum triangle tag is missing you will need to verify the model by other means.
To identify:
1) Locate the numbers of the fuel well body.
It's either under the fuel inlet fitting or as a "roll stamp" on the side of the fuel well body.
2) Locate the roll stamp number for the air horn body....It is located internally under neath the float.
3) Note the size of the main venturi....This is stamped internally just above the venturi.
4) Measure the diameter of the throttle bore....It is located on the cast iron mounting flange
5) Locate the number upon the metering cluster....This is an internal part suspending the boost venturi.
6) Note the size of the main jets 49 50 51 or 52

I suggest you buy a "Hygrade" kit. unless you have a #7026086
"Car Quest" brand is also made by Hygrade.
If you happen to have a # 7026086 Rochester the "Echelin" kit will be special for that model.

 

The engine is out of a 1971 cj5. Not sure how to tell if it had an air pump but I will look for the #'s on the carb.

 

Pevious post edited.
A 1971 would normally be equipped with a Rochester 2 jet # 7041185.
That number should be found just under the fuel inlet.

 

old time called these main jets, they are metering screws-- example, #51 is good from sea level to 4000 ft. above sea level, he is giving you good advise and that's what were all here for. wished you had waited before getting that napa kit, the results will no doubt be the same . i thought you said, your carb. had no roll stamp #? now i puzzled. good luck to you and happy jeep'n-- i'm happy just got another 1952 , m38a1 today -- my wife will kill me 6 jeeps just filled the shop.