'61 223 in F250

Hey guys, I apologize in advance for the long post, but I'm having some issues getting my newly purchased '61 F250 to run correctly. I read a couple of other post on this forum relating to my issue and tried what was suggested before I signed up as a member, but I'm hoping someone here can help me.

I cannot get the truck to idle at all without the choke partially on. In fact it does not seem to want to run at anything under about 1500rpm without the choke on. If I completely open the choke and hold the idle up (around 1200-1500) it has a noticeable stumble and struggles to run.

With the choke very slightly on I can get it to idle down to around 800rpm but runs pretty rough at that point. Any lower rpm than that it will sputter and die. It does not seem to be running off of the idle mixture screw whatsoever as turning it does not make any difference to rpm, vacuum or idle quality.

Carb was rebuilt by previous owner, I removed it, cleaned it out and blew compressed air as well as carb cleaner though all the passages. New cap, rotor, plugs and wires. I have set the points gap as well as the dwell per tune up spec. Found that the intake gasket was leaking so I replaced it. I even set the valves thinking that they were maybe too tight, when I checked them they were at .010 or less.

I have tried adjusting the timing and setting idle per a previous post, trying to obtain highest vacuum at idle, still won't idle. I'm currently at about 10degrees timing. The truck runs great down the road and seems to have the right amount of power.

Like I said earlier it does not seem to be using the idle circut, as I can see it pulling fuel through the main jet constantly at idle.

What am I missing? :banghead:

I was unable to find what the throttle linkage/carb setup was supposed to look line online, here is mine. Is this normal or am I missing and important piece? This spacer was installed between the carb and intake when I got the truck and I have tried tuning it both with it and without. I'm also wondering how the idle is adjusted as I do not see any idle adjustment screw besides the one on the choke cam, which to me would be the high idle screw.

Any help would be greatly appreciated

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Hi, find the correct valve lash from a Chilton's manual, or a member here who has that info. .010 seems tight to me. That could explain the vacuum issue. You also need to find out what spacer is best for your carb. I would think there are a few different ones available. It looks like a Holley carb to me, I'm not sure what might be missing from your idle stop. It is usually on the throttle shaft. There may still be more vacuum leaks to figure out. Good luck
 
I thought that .010 was pretty tight. I set them to .019 per the manual. I reinstalled the spacer, but the thing i think is the strangest is that there are 2 ports on the bottom of the carb base that lead to nowhere. Am I supposed to have a different base plate gasket? I see different ones online depending on what rebuild kit is used.

I do see that there is adjustment on the throttle linkage. Does the gas pedal linkage adjustment adjust the idle?
 
Those ports on the intake can be used for the pcv system or power vac assist brakes or both.
California came up with a canister that went from the down draft tube opening, via a tube that followed the intake, with a flange that bolted to your throttle pivot .
Then a pcv valve, rubber hose, brass fitting that entered the intake manifold. Both my 61 trucks had them installed.
 
Your carb linkage looks to be right however there needs to be a spacer under the carb to raise it up some. Without it this may causeing some binding of the linkage. Check to see that all your linkage points are in good condition and moves freely. The carbs upper (top) base gasket is different from the one used under the (bottom) spacer you could make your own until you can find the correct one you can also try NAPA auto parts they used to have a good selection of these spacer gaskets available. Basically you could just make a simple gasket out of thick gasket paper with only the two outside mounting holes plus the large center hole, the factory type gasket would have slots to conect to the bases vacuum pasages. Since you can't get it to idel down I would say you still have a bad vacuum leak or more left to find. Good luck on your 223 (y) :nod:
 
The screw that is against the choke cam is your idle adjustment. The choke needs to be completely open to make set the idle speed. Put a vacuum gauge on. I think you are dealing with a vacuum leak if you can’t get the idle below 1500. The most likely culprit is the manifold to head gasket. Try removing the vacuum line to the distributor and block it off. You might have a bad advance diaphragm. Next would be a crack or hole in the manifold. Good luck.
 
I had the exact same problem years ago, ended up being I had not adjusted my idle yet, as soon as that happened, it ran like a top.
 
In your original post you said you could see fuel flowing through the "main jet" at idle. Do you mean that you see fuel coming out of the brass tube (main nozzle) that protrudes through the gap in the choke plate in the narrow part of the Venturi? If so, or if you see any fuel coming out inside the carburetor throat at engine speeds less than 1500 rpm or so, then there is a problem with the main fuel circuit. Start by verifying your fuel level in the bowl, and making sure the two tiny air bleed holes beside the accelerator pump nozzle are clear.

At idle and near-idle speeds, all the fuel going into the engine should be coming out under the throttle plate from the idle/transition circuit. You may be partially flooding out.
 
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