Carburetor - Carter YFA 1-Bbl: Description

Carter YFA and YFA Feedback carburetors are made up of 3 main assemblies: air horn, main body and throttle body. YFA carburetors have an adjustment limiting vacuum diaphragm type automatic choke with an electric assist choke cap. The electric choke adds a high mileage economy application to the carburetor. The main body contains a temperature compensated accelerator pump which has a thermostatic disc designed to open and close within a specified range.

The YFA Feedback carburetor differs from the YFA in its addition of a feedback solenoid attached to the air horn assembly. This solenoid is used to meter air into both the idle and main circuits for improved engine performance. A Microprocessor Control Unit (MCU) senses various engine needs and supplies feedback fuel as required by forcing air into fuel bowl, and in turn, more fuel into carburetor air stream.