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I have this instant bogdown when I hit the accelerator. It seems like it is flooding. I have to pump the peddle a little then roll on it slowly or the motor wants to stall. It is worse when it is cold, but still does it slightly after warm. It is only on takeoff. if I am moving it is fine, I can stomp on it. Could I have the accelerator pump set wrong? Something is not right...
Likely you have an air leak. Have you tried spraying starter fluid around the top of engine while it's idling and listening for an idle change? It will rev when the motor sucks the fluid into the air leak.
Prone areas are where heads meet intake manifold and any vacuum lines / plugs for rubber goes bad.
An instant bogdown or hesitation points towards the accelerator pump inside the carburetor not providing a "shot" of extra fuel when needed. When the accelerator is pressed, the butterflies open up and the fuel velocity drops to almost nothing for a second, so there needs to be a squirt of extra fuel to compensate or there will be a bog or stumble. With the engine off, blip the throttle while looking directly down carb throat. Look for two squirts of fuel immediately when throttle starts to move.
Make sure the pump rod is set at the right slots fore and aft, and replace the pump. They are standard replacement parts in rebuild kits, the little red umbrella lookin' deal.
If you go to places like Mikes Carburetor website (there are others too) you can download the 2100 manual and rebuild instructions and setup and tuning tips, and order a rebuild kit. The 2100 is one of the best carburetors ever designed with annular discharge nozzles, they are very simple and reliable. Unfortunately modern fuels don't play well with carburetors, so they need rebuilding every few years.
Pay mind of setting the float height correctly and then check that the resulting fuel height in the bowl is within spec as well, everything with carburetor tuning downstream, high speed operation, jetting, smooth idle etc is predicated on this being correct.
Make sure the pump rod is set at the right slots fore and aft, and replace the accelerator pump.
They are standard replacement parts in rebuild kits, the little red umbrella lookin' deal.
The "little red umbrella lookin' deal" is the accelerator pump check valve (9576 in pic). The accelerator pump is shown as 9B559 in the pic.
The 2100 carb kit includes the accelerator pump and its check valve. SAME kit for all 1962/74 2100 series 2V carbs in Passenger Cars, F Series Trucks; 1966/74 Bronco's & 1969/74 Econolines.
D4AZ-9A586-A (replaced C2AZ-9A586-B) .. 2100 series Auto-Lite/Motorcraft 2V Carburetor Kit (Motorcraft CT-499-D) / Available from Ford & auto parts stores.