Late model carbs with side-mounted pumps use the elastomer valve, rather than the earlier model check ball style. The long stem of the valve is for installation so you can pull it through the hole with a pair of pliers. Oil up the stem before trying to install the check valve. The stem should be cut off after installation or it might interfere with the float.

The 2100 main jets are in the bottom of the bowl; right next to them you can see the top (stem bottom) of the power valve which is threaded through the exterior bottom of the carb. .

Discharge weights are necessary in some cases to keep the check ball seated, as seen in this image. Not all 2100 carbs use the discharge check weight. Check the diameter of the venturi retaining screw. If the orifice is smaller than the OD of the check weight, your carb does not use the check weight.

One of the changes in the 2100 is the vacuum break mounted on the cover. It connects through an internal passage to manifold vacuum and pushes the choke open - as shown - when the engine starts.

Many people ask if this can be removed when the choke is converted to electric. The answer is no. This vacuum break serves a different purpose and works in coordination with the choke thermostat.

Vacuum break AKA:

Choke pulloff

Choke pulldown

When overhauling a 2100 or 4100 carb, it’s a good idea to leave the cover off and check the actual wet fuel level, after you get the carburetor mounted on the engine.

A “jet wrench” is not necessary if you are careful to get a screwdriver that fits the slot in the jet. If possible, check the head of the jet for the size stamped before removing the jet in case it gets damaged on removal and needs to be replaced.

Here’s the way the solenoid throttle positioner works. When the solenoid is energized, the throttle is lifted off the normal idle-speed screw, as shown by the gap (arrow).