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Post by Scoutpilot on Oct 28, 2019 11:13:36 GMT -5
Raise the pin. Back in the day, the eye of the rod was round, not oval. The gauge won't help you. Put it away.
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Post by jeepsaffer on Oct 29, 2019 3:50:00 GMT -5
Thanks Scout, i've followed your advice and reset the pin so it is JUST clearing the inside top of the rod eye. Intuitively it looks much better.
I trust your vast knowledge on these carbs, so to be clear I'm not about to argue with you! But for my better understanding, I would appreciate your comments on my thinking below.
The metering gauge is supposed to set the distance from the metering rod jet to the underside of the pin, and by default to the top of the pin (if all pins are the same diameter). The top of the pin is where the metering rod "hangs". So by using the gauge one should be setting the distance from the jet to the inside top of the metering rod eye. If this is all correct, then the shape of the rod eye (round or oval) is irrelevant, provided the distance to the inside top of the rod eye is correct, not so?
I'm just trying to get my head around why the jet to eye distance is so important to get correct that they made a special gauge for it, yet in my case the gauge turns out to give an incorrect measurement and i've ended up doing it by eye anyway... Hmmmmmmm.......
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Post by Scoutpilot on Oct 29, 2019 5:38:25 GMT -5
The reproduction rods are slightly longer than the original ones due to the elongated eye. They sit higher. It's that slight difference that negates the gauge's usefulness.
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Post by jeepsaffer on Oct 29, 2019 8:04:42 GMT -5
Ahhhh.... gotcha. Makes sense now.
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Post by jeepsaffer on Oct 30, 2019 3:39:30 GMT -5
Hey Scout, so I got the carb all back together last night after work when the family were in bed. I've come a long way! This is what I started with:  And this is how it came out:   I'm pleased with the end result, especially seeing as this is my first rebuild. I learned a lot along the way. I might get time this weekend to install it back on the jeep. I hope it solves some of the problems I was having, which spurred this rebuild in the first place! Thanks for your help along the way. I'll be sure to let you know how it is performing once it's installed, and if there are any final adjustments to be made. Mike |
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Post by Scoutpilot on Oct 30, 2019 5:55:11 GMT -5
It does look good, doesn't it? You have come a long way. Let's finish the journey!
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Post by jeepsaffer on Nov 16, 2019 4:32:41 GMT -5
Hey Scout, the other package with the gasket set and throttle linkage spring came in this past week. Thanks!
Question: The conventional advice is to "pre-crush" a new carb to manifold gasket where it has the copper reinforcing around the stud holes. How exactly is this achieved? In a vice? Do they crush evenly or will they crinkle? How much do you crush them?
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Post by Scoutpilot on Nov 16, 2019 5:11:14 GMT -5
Place the gasket on the manifold. Install the carb. Tighten the nuts to 30-35 pound-feet of torque.
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Post by jeepsaffer on Nov 16, 2019 8:13:52 GMT -5
OK, so just to be clear, NO pre-crush of the copper rings is needed? The installation will crush them just fine?
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Post by Scoutpilot on Nov 16, 2019 11:43:16 GMT -5
No pre-crush required. I've been installing them like this for years.
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Post by jeepsaffer on Nov 23, 2019 8:41:28 GMT -5
OK, some progress! I started the jeep up and it runs.... so i guess that's good.
I was still fiddling with a few things when the rain come down, so I'll give it a break for a while.
What would be the cause (and remedy) for a stumble upon pulling off?
Metering rod set too low, and solution being to raise it up a touch?
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oilleaker1
Full Professor
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Posts: 2,022
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Post by oilleaker1 on Nov 23, 2019 9:25:48 GMT -5
Two causes, accelerator pump is not squirting fuel into the venturi, or the metering rod is late pulling up out of the main jet. Drop the metering rod all the way down, get a nice idle, then set the rod to immediately pull up upon demand of your foot!. You've been at this project for a long time. It sure is looking good! Oilly
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Post by jeepsaffer on Nov 23, 2019 23:44:20 GMT -5
Thanks Oilly, i have been at it a long time! Nearly there, i think. Just have to get this carb/fuel/idle issue sorted out. I'll work some more on it today.
You were the very first person to reach out to me, over on the CJ2A page. You sent me a PM with advice on how to adjust the valve lash. Do you remember that?That was 2014.... Seems like an age ago.
I appreciated the advice then, and it gave me the confidence to start engaging more on the site, which ended up being invaluable for my build. I also learned quite quickly who knew their stuff and were prepared to share it without a fuss, and who the idiots were. I've noticed that quite a few of the good folks hang out here.
I'll keep going until i get this right. Quitting is not in my nature!
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Post by jeepsaffer on Nov 24, 2019 3:29:03 GMT -5
So i have spent the last few hours working on the jeep. Wow.
First off, I did adjust the metering rod higher. It no longer wants to quit when I give it gas. So that's one for the up side. Now for the downside...
Idle is still very rough. Without choke the revs seem to hunt up and down. It gets to the point of quitting, then there is a little uptick and it recovers, then the pattern repeats. The cycle is quick, like 1-2 sec long.
Timing is set at IGN in the peep hole window. I advanced it so that I can still see the IGN in the window, but more towards the bottom of the window.
Dizzy is rebuilt.
Leads and plugs are new.
Plugs were cleaned after carbon fouling from my previous attempts prior to the carb rebuild.
Dwell angle is at 41 degrees.
Carb is rebuilt. Throttle has been rebushed by Scout. I can see fuel squirting into the venturi when I open the throttle, so the accelerator pump works. I can see fuel dribbling in from the nozzle at idle.
Fuel is fresh (tank was drained and fresh fuel put in). I have a carter ceramic element glass bowl filter between the pump and the carb.
I changed out the dizzy condenser just for kicks, with no change.
Coil is new.
I cleaned, polished and retightened the engine grounds strap and contact points.
I changed the rotor for a new one, with no effect.
With a warm engine I started on 1.5 turns out from the bottom with the idle mix screw - it wouldn't run without choke.
I went out in half turn increments, progressively pushing in the choke.
I'm now on 3 turns out on the idle mix screw. If I nurse it it will idle rough without choke, threatening to quit at any time, but if I give it gas, it will rev up and then rev down and die.
Does any of this make any sense? I'm running out of things to try (and my sanity)...
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oilleaker1
Full Professor
Full Professor
Has Jeep Disease
Posts: 2,022
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Post by oilleaker1 on Nov 24, 2019 5:10:56 GMT -5
I believe you have a vacuum leak at the carburator base gasket. Those new rivets around the stud holes in the heat insulator block when new, cause many problems with idle mixture. Lee and I worked on a guys Jeep that had spent three years paying mechanics that didn't have a clue about old Jeeps. I felt sorry for him. The mechanic had ruined his carburator. Stripped out screws etc. Whenever you have to add in choke, it's a sign of bad idle mixture. So, you may have to snug down the two nuts that hold the carb down to the intake, or add in a thin paper gasket top and bottom. I kept having my CJ3A lose idle because the nuts would work loose. I put some thin star washers there to stop that. Be careful you don't chew up the metal or get rough with it. I also had the slow speed circuit jet that came in a new kit end up with too small a hole or orifice. (located at the outside front under the flat small cap and it is long and skinney) I cleaned the old original and put it back. They make tiny pilot orifice reamers for propane pilot jets. I keep them in my tools for doing delicate jet cleaning without over sizing them. If you get confused like I do, a can of carburator spray cleaner can help determine if you have a fuel delivery problem. If you spray it into the carburator while the engine is running and it recovers and runs good, you have a lean or fuel starvation issue. I had a mechanic teach me that on my M38A1. 1 1/8 turns out is where you want to be or close to that. I close my mixture screw down until the idle noticeably begins to drop. Then back out until it just smooths out. A vacuum gage attached to the intake is another tool to use when setting mixture. The highest reading is where you want to be at idle. On timing, a rule of trail thumb is to advance the distributor to the fastest idle, then retard 100 RPM's and you will be within 2 degrees on timing. I'm glad to have my Jeep friends. They are some of the kindest, best people I've ever met. When you are out in the boondocks where there is just you and your friends and no one is coming to get you, your Jeep pals are comforting. They teach me things also. Love it. Tools, parts, techniques, come flying out of no where. very cool bunch of friends. You provide the kind of info. that tells me you're on it! Keep at it, it will come around for you. Just hang here and we'll try and help. Oilly PS ------I forgot to mention Lee is a parts dept. on wheels. LOL. He didn't have one, no, he had two extra re-built carburators with him that day. Lee is our go to guy!  |
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Dec 2, 2024 11:19:42 GMT -5
Dec 2, 2024 11:19:42 GMT -5