A diaphragm carburetor is disclosed wherein a mechanism for varying the fuel flow rate through the carburetor for delivery to the engine can be controlled by electronic feedback based on engine performance. A permanent magnet/wire coil assembly is attached to the diaphragm controlling the opening to the metering chamber within the carburetor. The assembly responds to commands based on engine performance and can vary the size of the opening to the metering chamber. In this way, the fuel flow rate through the carburetor can be modified to obtain the optimal fuel/air ratio for peak performance of the engine.