(1) Compatible Models: Specially designed for 1905 AVS2 500CFM Carburetor (Part Number: 1905). In the middle of the air intake channel of the carburetor is a narrow throat. - Carburetor Structure: The components of a carburetor usually include a liquid fuel storage chamber, a choke, an idling (or slow-running) spout, a main spout, a venturi-shaped air-flow restriction, and an accelerator pump.