Carter AFB Carburetor Adjustment Clarification

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TonyC
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Carter AFB Carburetor Adjustment Clarification

Post by TonyC »

Hi, all,

As part of the ongoing drama with my engine, I decided to focus now on the carburetor. Here's the prologue for my upcoming question: Last time I cranked the engine, last week after replacing the starter, the engine fired up and then choked out after about two or three seconds; it did this twice in a row. This is a step forward, I must admit, but still not far enough to claim success yet. I started thinking back to the day of the coma, when the engine ran smoothly to the gas station but ran terribly rough on the way back, forcing me to keep revs high to fight a potential stalling, and belching thick smoke out the rear all the way up to the hotel where the engine finally went comatose. This reminded me of similar symptoms I remembered experiencing in El Paso about a dozen years ago, which led to the first rebuild of this carburetor. On a hunch, based on all this, I felt that the carburetor might still have internal issues even after the disassembling I had done at the beginning of this ordeal. I took it off with intent to tear further into it, but I shredded one of the secondary jets trying to remove it for inspection and cleaning. All my attempts to extract what was left of it damaged the threaded bore that jet is supposed to screw into, rendering the carburetor unusable and forcing me to look for a replacement. Luckily, John Brewer was selling one on E-Bay for $60, so I snagged it; even though it was missing some parts (some may have been removed in a prior rebuild, some may have never been installed, I don't know), it was in very good shape, even better than my old one for the most part. I took that one apart, went through a very meticulous cleaning and inspection, transferred what parts were missing from my old carburetor to the "new" one, and now I have it installed on the engine. But I haven't tried cranking it yet, partially because I'm afraid of being disappointed again, and partially because I am not sure if I have it initially adjusted properly to try cranking. I have always had difficulty trying to follow the shop manual's guidance on how to adjust everything; some things are pretty straightforward, but when it comes to sequence of all the necessary adjustments I still have problems following it.

So, here's my question: Where do I go from here? I have confirmed the float clearances, and I set the idle speed and mixture screws to initial specs in the manual. That's all I've done so far. Nothing else has been adjusted, and I need to know what else I should adjust before trying to crank the engine up again. I'll keep studying the manual, but clarifying input would be appreciated.

(PLEASE, folks, don't waste precious bytes telling me to just get an Edelbrock. I have no desire to go through any more crazy modding if I don't have to. I'm sticking to OEM, so please keep the input focused on sequence of tweaks to adjust an OE Carter. For those who will do it anyway just to get on my nerves, VERY FUNNY!!!! :smt005 :P )

---Tony
"Don't believe everything you read on the Internet, just because there is a picture with a quote next to it." (Abraham Lincoln, 1866)
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1966 Continental Sedan, affectionately known as "Frankenstein" until body restoration is done (to be renamed "General Sherman" on that event)
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Re: Carter AFB Carburetor Adjustment Clarification

Post by RMAENV »

Man, do I know that feeling. Especially as I get older. It's a confidence issue. I would open it 1/2 turn rich and give it a try. Adjust leaner after start. Go for it Tony. You will be fine.
Rob
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Re: Carter AFB Carburetor Adjustment Clarification

Post by George W »

Ran poorly after the gas station? Could you have possibly gotten contaminated gas ? Even a worn out carb should let the engine run to some degree. You can always get a short length of gas line, disconnect the supply line side from the fuel pump and use a temporary gas can to insure you have good gas. You can deal with the idle and choke settings once you have the engine running and up to normal operating temperature.
One of the few things that would cause flooding out would be a sticking float valve or a bad float. Not likely an issue with your "new" carb.
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Re: Carter AFB Carburetor Adjustment Clarification

Post by TonyC »

Thank you, Rob, George. :smt006. I read the entire general-service chapter last night and came to the same conclusion, to try and get a running engine and deal with the further tweaks afterward, so that is what I'll do.

I did a gas check yesterday. I cranked the engine over enough to catch about 7 spurts of gas from the pump into a glass to check for any visible contamination. Aside from the coloring looking like half-diluted apple juice, I saw nothing; it was clean. I suppose the idea of bad gas is possible, but I'd think an engine in good operating shape would burn it all out instead of choking itself into a coma...unless somebody sugared my tank, which I know is impossible.

There was also something very curious that I noticed on my old carb when I went into it this last time. For the first time ever, I completely removed the choke housing with intent to swap it into the "new" one, because the choke on the Brewer core just did not give me a warm-'n'-fuzzy feeling. When I did, I saw very thick soot deposits inside, which were jamming up the mechanism that should be clean and loose. I don't know how that happened, but I wonder if that could have been a contributor to killing the engine when it fired up. I dropped the whole choke in solvent, sprayed it clean, replaced the small gasket in the vacuum port (which I did not know about until yesterday), and put it on the "new" carb. I'll see soon what difference that makes.

George, you brought up something that I did notice during my rebuild. Since I chose to use the air horn of my old carb on the "new" one, mainly because the "new" one was missing all its internal baffles, the float needles could cause me trouble. When I uprighted the air horn to check the drop specs of the floats, the needles did not drop out of the seats, not even when I sprayed into the fuel inlet. I didn't bother swapping them out, because they are new and I figured the pressure of incoming fuel should knock them loose. But if the engine still chokes out when I crank it, I may just do that; I still have the old pair of inlet needles on hand.

I'll give an update when I know the results. Wish me luck!

---Tony
"Don't believe everything you read on the Internet, just because there is a picture with a quote next to it." (Abraham Lincoln, 1866)
"Question Authority!"

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Re: Carter AFB Carburetor Adjustment Clarification

Post by Dan Szwarc »

I was gonna say just get an Edelbrock. :D

Seriously, though. i couldn't be happier with mine. I get 12.7MPG in the city and 14.3 on the highway at ANY Speed. It's adjustable, parts are available, etc. and it's not worn out like my original carb.

I always wish Tony the best!
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Re: Carter AFB Carburetor Adjustment Clarification

Post by George W »

You used the phrase "choked out". To me that means the car would have been running way too rich and flooding out due to the choke being too far closed or a needle valve / float hanging up causing flooding of gas down into the intake.
On the other hand if the car were starving for fuel you could verify by keeping it running by spraying spurts of starting fluid down the carb with the choke plate open or partially open.
Let's see what happens now that you've tweaked the carb.
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Re: Carter AFB Carburetor Adjustment Clarification

Post by tomo »

I am not sure about the 66 Lincoln, but my 53 has a tube that fits in the intake and is exposed to the exhaust gases that heat the carburetor. When the tube rusts out, exhaust gases get into the choke housing gumming everything up.

Tony, did you give the gas in your tank the smell test? That gives a better indication of bad gas or diesel contamination.
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Re: Carter AFB Carburetor Adjustment Clarification

Post by frasern »

there are places where you can have a fuel sample tested, low sulphur diesel may not have a noticeable odour. I will not suggest a burn test, even a small one.
I have many running parts trucks, which I won't run with the fuel in their tanks. If I want to run one, I use a remote tank, with known good gas. A similar thing can be done, for testing, with a small bottle of good gas, hung like an I.V. from the hood, hooked up to the fuel pump. It should even work hooked up to the carb, I have run with gravity feed before. Of course Caution and a nearby extinguisher are in order.
The choke stove, on the 462, is a plate, on the exhaust manifold, which does not penetrate into the exhaust, so that one is rather odd. They commonly plug up inside with rust, so if you didn't already, remove that plate and clean it. This will keep air flowing through the choke and may keep it cleaner inside.
Edit; The bolt on that choke stove will be rusty, and may require heat to free it. Maybe hold off on that, until you have the car in the shop.
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Re: Carter AFB Carburetor Adjustment Clarification

Post by TonyC »

I was gonna say just get an Edelbrock. :D
Somehow I knew you'd do that, Dan! :lol: I will let you know, though, that since UglyViking's posting of the 1906 model, I am giving an Edelbrock conversion more thought. Yes, I am too lazy to try rerouting the fuel line to the wrong side, I'll admit; besides, with the stuff that's in the way already, I prefer not to try figuring out the plumbing, even if I do have examples of others' conversions to use as a guide. That wasn't the only thing that made me reluctant, though; I have A/C (the fact that is doesn't work is irrelevant, as I have intention of addressing that), and the absence of an idle speed-up solenoid just turned me off. But since the 1906 apparently has provision to install one, plus the loss of the famous Baker rebuild kits, that adds appeal to going Edelbrock. I found a 1906 yesterday on E-Bay for a nice price, so I saved that listing to my watch list; if I make no progress at all this week, I may just do another parts-toss at the problem. I'll have to go back to the other thread to see what mods may still be necessary to that, however.
Tony, did you give the gas in your tank the smell test?
Well, Tom, I didn't smell anything odd about the gas. Granted, it's three months old, but that's not long enough for gas to break down. It did smell like gasoline, nothing suggesting diesel contamination.
The choke stove, on the 462, is a plate, on the exhaust manifold, which does not penetrate into the exhaust, so that one is rather odd. They commonly plug up inside with rust, so if you didn't already, remove that plate and clean it. This will keep air flowing through the choke and may keep it cleaner inside.
Yes, I took care of that already, Fraser, back in March when I did the head swap. I know the stove passages are completely clean; my right exhaust manifold is only a couple years old and was brand-new when I got it, so that was the easy part of that job. Unless somehow sooty deposits were sucked up through the one pipe at the carb's back, through the stove, then back through the other pipe into the choke, I cannot see how soot could possibly deposit inside the choke. I don't know, that was a very odd mystery.

I'm going to try leaning the mixture, which somebody on one of the Facebook groups also suggested; see what happens then.

Follow-up: Well, I saw what happened...or, to be precise, what didn't happen. After fiddling with the speed and mixture screws to the point I found myself repeating settings, I stopped to scratch my head some more. Now the issue doesn't sound like fuel anymore. When I had the distributor twisted at its max advance angle, butted right against the fuel pump, the engine fired and I was able to keep it revving, with effort, for about half a minute before it went out again. I twist the distributor back, it becomes harder to fire and hold, plus the chance of backfire through the carburetor increases. Now I'm thinking I need to fiddle with the distributor again, for the 11th time.

---Tony
"Don't believe everything you read on the Internet, just because there is a picture with a quote next to it." (Abraham Lincoln, 1866)
"Question Authority!"

1966 Continental Sedan, affectionately known as "Frankenstein" until body restoration is done (to be renamed "General Sherman" on that event)
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