Carburetor Is Flooding

These are the most likely causes.
The needle and seat is not closing. Most likely there is dirt causing it to stick open, but the needle could also be defective.
The float level is incorrect.
Gas is getting inside the float making it heavier than normal.
Carburetor unloading isn't correct. Depress the throttle all the way. The choke plate should be opening.

To eliminate the above causes, the carburetor should be rebuilt.

The Engine Hesitates When Accelerating.

Most likely the accelerator pump is defective.
Rebuild the carburetor.

Engine Surges

Fuel restriction. Check the lines for bends and kinks. Replace any badly worn hose.
Dirt, or water in the fuel. Clean out the gas tank and change the fuel filters.
Main jets may the the wrong size. This would be due to someone changing them recently.
Vacuum leak. Check the carburetor throttle to make sure it isn't loose in the throttle body. Might be a leak at the intake manifold, or perhaps where the carburetor mounts to the manifold.
Fuel level is too high, or too low. Check the float level.

Choke Problems

When the choke isn't opening like it should:
For the thermostatic type of choke with the metal coil -  heat up some water and place the choke in the water. It should look like it's unwinding. If it doesn't, then replace the choke.
Electric choke - Simply hook up the two leads to the choke to a 12 volt source. The choke should open fairly quickly.
Some models have the choke mounted in the manifold. The heat from the manifold heats up the coil making the choke open. Assuming you have already tested the choke in hot water and it works fine, but doesn't work when on the car, then chances are the manifold isn't heating up the choke. This is probably due to the manifold being clogged around the choke area.

Tips on Removing and Replacing Your Carburetor

One of the most helpful thing you can do while removing your carburetor is to get your digital camera out and take pictures of every step you take, then put the pictures on your computer for later viewing. Take pictures from every angle including several close ups. I do this on every carburetor I take apart on the bench. Any time I have a question, I refer backto the pictures.
Lacking a digital camera, make a drawing as accurate as possible that will show where things go.
Mark your vacuum lines with masking tape, labeling each one.
Stuff a rag, or towel down the carburetor throat to prevent you from dropping anything down the carburetor. You don't want to be forced to remove the manifold, or heads looking for that small screw.
When removing bolts and screws, start them back into the base unit so you have the correct size bolt later.
Do yourself a favor and use flared nut wrenches to remove the fuel line.
After the carburetor is removed, stuff the manifold opening with something to keep foreign material out of the manifold.
Remove the base gasket from the manifold. Keep in order to match it up with the new gasket. There can be very suttel differences in some carburetor gaskets.
Clean the old gasket off of the manifold. Be careful what you use so that you don't damage the manifold metal while scraping. A dremmel tool works good here.
If your vehicle has been sitting for a year or more, drain the gas tank. The gas is probably stagnant and will ruin an otherwise good carburetor rebuild. Better yet would be to remove the gas tank and have it boiled out.
Change any fuel filters before running the new carburetor.
When bolting the carburetor back to the manifold, don't over tighten, or you may warp the carburetor base. Don't tighten more than 10 lbs. That isn't very much.
In summary mark, map, label and be patient. You will have a smooth carburetor job.

Does your carburetor need to be rebuilt?

One simple test you can perform on most carburetors is to adjust your idle mixture. The engine should respond to your adjusting the idle mixture screw. If not, then the carburetor probably needs to be cleaned.

Another indication could be when your carburetor is flooding. You might see the fuel flooding into the carburetor, or perhaps you are getting a strong gasoline smell while running.

Surging can be another indication. This results from plugged carburetor circuits. Fuel comes and goes, which causes a surging action.

Does your fuel smell like varnish? When a carburetor has been sitting full of gasoline for a year or more without being run, then you will most likely need to have the carburetor cleaned along with draining your gasoline and changing the fuel filters.

When you try to accelerate does your engine hesitate? This is an indication that your power circuit is defective.

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Rochester, WA 98579

360 347-1077