Autolite 4100 running extremely rich

I just rebuilt my Autolite 4100 and now it running extremely rich (fat). Anyone have any suggestions on how to lean it up a bit? It sounds like it's missing. Checked spark plug wire placement and all seems to be in the correct order. This is my first restore. Thanks!!

 

Recheck float level.

 

you might check for a vacuum leak also.........

 

hey scrap....how should i check for vacuum leak...any special way of doing that? thanks!

 

Check the power valve for damaged diaphragm.

Bob

 

Correct spec jets?

 

Recheck float level.
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Check the power valve for damaged diaphragm.

 

what they said, recheck float and make sure needle/seat combo is working as it should.

 

There is no power valve on an Autolite carb. Also, a vacuum leak would make it run lean...Re-check the float level...

 

True that

 

This might help...
http://arrc.epnet.com/autoapp/9060/9060CH5_Carburetor_Assembly.htm

 

and this
http://www.mustangmonthly.com/howto/mump_1012_autolite_4100_carburetor_installation/index.html

 

I noticed in the caption about hooking up fuel lines to use teflon tape on the fittings.

1) shouldn't need it if the fittings are correct and in good shape

and

2) teflon tape... really??

 

Say no to teflon tape on fuel threads!!!!!! peace

 

4100s (and the 2100 two bbls) have what Ford called an economizer valve..It shut off fuel at higher vaccuum...Holley called them a power valve..same thing, and if the diaphragm is blown, it will flood just like a Holley does when the power valve is blown, usually resulting from a backfire...

 

Is it dumping fuel down the venturies at idle? (check it by looking down the carb with engine running)

Is it rich at all speeds or RPM?

 

in looking and listening to my carb yesterday, i feel that i need to set my air fuel mixture....still running a little rich. anyone have any advice for tuning these?

 

If you are SURE everything is working correctly, and no fuel is dripping down inside the carb at idle, set the idle mixture by screwing the idle jets down until they stop (DON'T tighten them), and back them out 1 1/2 turns. Start the car and adjust the idle speed to about 650 rpm. It should idle nice and smooth. If not, you have a problem somewhere.

If it idles ok, open each idle screw 1/2 turn and watch (or listen to) the engine speed. If it goes up, reset the rpm to 650 and try again. At some point, the next 1/2 turn on the idle screws won't cause any increase on speed. Back them in 1/2 turn and you're done. If you get out past 3 turns and it's still picking up, you've got a vacuum leak somewhere.

(Keep in mind this is only adjusting the idle mixture. If the engine is running rich at higher rpm, you need to re-jet. And again, ALL of this depends on the carb working correctly in the first place.)

 

When I screw in the air / fuel mixture screws, the idle goes up and when I back them out, the idle goes down. Is this correct?

 

I would slap a vacuum gauge on it and go with the highest vacuum reading.

Bob

 

So I have the same problem, runs fat un-burnt fuel smell, looking down carb I see fuel leaking from the right front vetury. I have cleaned every port on carb, blew carb cleaner in every port, slot, hole. Replaced power valve, gasket sets, checked float levels, took top of carb off off and run car, still gas flows out ventury. Checked for vacuum leaks and all checks out Help me.

 

Idle adjustment screws do not effect idle, either