Looking over my carb I found this. Where does it go?

 

That is fresh air to the exhaust that would return to your thermostat as an assist. There would be a small hole in the exhaust manifold where that inserted prior to it rusting out. If you do not have a need for it, just cap the outlet on the carburetor.

 

Thanks bcamill! What would qualify as not needing the assist?

 

The weather you are in. Since I assume it has not been attached, have you had any issues with warm up. The electric choke is normally all you need. That part is just to supply warm air to the thermostat to help the spring more. If it seems to be warming up fine and no stalls, just plug it. That part is hard to find. Usually only in the junk yard if you are lucky. You could make one with a double flaring tool to insert back into the exhaust. Have you located the one coming out near the top far back of the exhaust manifold leading to the choke?

 

I haven't had the chance to dig around and find it. I'm in Georgia so it may not be necessary. The amount of stuff hanging off this carb is crazy. My dad's 76 didn't have any of this. I would love to simplify this thing. I don't have to worry about emissions here. Any suggestions on where to look for deleting things?

 

Do you have an air pump still on the vehicle? If you are attempting to get rid of all emissions, then the pump and all lines to it can go. This will free up some HP. Things like the EGR are OK to go, but if it is working, I would leave it alone.

 

That is your "fresh air" tube. It is part of the thermostatic choke system. The loose end connects to the bottom of the choke stove chamber, which is attached to the exhaust manifold. It looks like it rusted off. Even though your choke should still be working fine, you are currently pulling unfiltered air through your choke stove chamber and ultimately, through your engine.

This is the idea on how the choke stove was originally setup:



A thermostatic "hot air" choke in conjunction with an electric assist is what Ford used on the stock Autolite and Motorcraft carburetors. The way it works is this:

Clean, filtered air from the air cleaner is pulled through the "fresh air" tube (a rubber hose that is connected to the carburetor air horn and attaches to an aluminum tube) and into the bottom of the choke stove chamber on the exhaust manifold, where the air is heated up when the engine is running. From there, the heated air goes back up through the insulated "hot air" tube (attached on the top of the choke stove chamber on the exhaust manifold) that connects to the choke cap. As the air gets hot, it closes the spring in the choke cap, which allows the choke plate to open up as the engine warms up to run on a leaner mixture.

That is incorrect. You actually have that backwards.

The "electric assist" portion of the stock choke system does not work on its own like an aftermarket electric choke. In fact, it doesn't have to work at all in order for the hot air choke to be effective. It is only there to "assist" the thermostatic choke in temperatures above 60 degrees, where it helps the choke come off sooner for cleaner emissions. It doesn't work at all when the weather is colder than 60 degrees. It connects from the spade on the choke cap by a wire that connects to the back of the alternator. This part of the choke is secondary, meaning the choke will work fine without it, but the choke will not work without the thermostatic "hot air" choke system.

Capiche?

 

I think I understand LARIAT 85. Your saying that I should fix it. The electric choke on these is an assist not the main choke.

 

Here is something written awhile back when I was working through what you are looking at.


https://www.ford-trucks.com/forums/1...ent-101-a.html

 

Thanks 1986f150six. Great read.