Fuel Control

All models are equipped with a feedback carburetor which contains an electro-mechanically operated mixture control (M/C) solenoid. The M/C solenoid regulates the air/fuel mixture according to commands from the MCU. One terminal of the M/C solenoid is connected to battery voltage (12 volts) and the other terminal is connected to the MCU.

The MCU functions as a switch that either provides a ground for current flow to energize the M/C solenoid or an open circuit to de-energize the M/C solenoid. The MCU switches the M/C solenoid on and off about 10 times per second.

When the M/C solenoid is energized, a needle is inserted into the jet resulting in a lean air/fuel mixture. When the solenoid is de-energized, the needle is withdrawn from the jet resulting in a rich air/fuel mixture.