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Autolite 4100 Help


I just discovered this forum....looks great. Here's a question I asked on another forum  a couple of days ago. I need all the help I can get.

I just installed a "rebuilt" Autolite 4100 on my '66 Gt. As soon as I fired the engine , gas started pouring from the carb vents and quickly filled the depressions in the intake manifold . To say it was "flooding" would be an understatement.

Based on my limited carb knowledge and some research, it seems the only possibilities are dirt, a stuck float, a bad needle valve or an improperly adjusted float.

After posting yesterday, I removed the floats and needle valves and blew out the fuel passages with carb cleaner. When I restarted the engine....same flooding issue.

All parts seem as new and moving freely.

Today, I removed the air horn, and found only a small amount of fuel in the bowls and the floats at "half mast".

I then added fuel to the bowls manually and the floats rose as in the pic. Does that necessarily rule out the floats as the problem?

As explosive welcome. No smoking in the refueling area. The shut off for gas is the needle valves. There is a "backwards" check. Remove the carb; raise the floats to where the needle valves are closed (you hope) and hold them there (small screwdriver, steel rod, popsicle stick, etc);  fill the bowls with gas; observe the fuel inlet hole in the front. If you got leakage, the needle valves are bad; if you don't, you may have an over agressive fuel pump.

That second picture shows the bowl as being way too full.  Adjust the float where the bowl is only about 1/4 full at any given time.  Did you replace the power valve when you rebuilt it?  And Jim may be onto something with the needle valves.  Even though they may be new, they still may be defective. 

Something else I just noticed - you have the choke setup for a 4300 carburetor, not a 4100. The 4300 has an insulated tube with exhaust heated air from the right hand exhaust manifold going directly into the round cover of the choke, the 4100 has the equalivent tube connected to the left rear base of the choke housing and the heated air is fed into the cover area thru internal passages. Plus the heater hose with hot engine water should be held to the side of the choke cover with a bend in the choke shield.
With this in mind, lets go to some basics. The Ford part number for your carburetor is located on the left front mounting ear. In your picture number xxx011, that would be the ear closest to the bottom of the picture. Give us that p/n and if that carb was supposed to be as original, and if you know the source of that carburetor, be prepared to do some strong words.

Take the carb off and hold it upside down, then use that little white measuring device  that came in the kit to get the floats at the right setting.  Follow the directions that came with the kit to get that exact setting mark.  A flooding carb simply means there is just too much gas being allowed into the bowls.


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