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



A thermostatic "hot air" choke in conjunction with an electric assist is what Ford used on the stock 1 and 2 barrel 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.

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 hot air 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 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.

If your original choke tubes have rusted off, you are going to have to remove the exhaust manifold from the engine and drill out the broken tube(s). If you bought the universal Choke Stove Kit, it is designed to bypass the choke stove chamber on the exhaust manifold and replace the stock choke tubes completely. The kit comes with a length of coiled up aluminum tubing that you can easily bend by hand, the tubing insulation, the hardware to mount the tube to the choke cap, and a little "dome" with a hole in one end for the tubing to push into. This dome clamps to the exhaust manifold or header pipe to trap the hot air when the engine is running and routes the hot air up to the choke cap.

Here is a picture of the universal Choke Stove Kit on my own truck. I have a V8 engine, but the concept is still the same:



The factory setup had a "fresh air" tube that routed from the carburetor air horn down to the bottom of the choke stove chamber on the exhaust manifold. This location provided filtered air because this area is located on the "filtered air" side of the air filter once the air cleaner is in place. I drilled a second hole on the other end of the dome that came in the Choke Stove Kit so that the hot air going into the choke cap would be filtered, more like how it originally was set up in the first picture. You can see where mine attaches to the carburetor air horn by the rubber hose right behind the choke cap.

The universal Choke Stove Kit doesn't use the "fresh air" portion of the hot air choke at all.

 

Thanks for the A+++ post!