Fuel Control

All models are equipped with feedback carburetors which contain an electronically operated stepper motor. The stepper motor controls metering pins which vary the size of idle and main air bleed orifices in carburetor body.

The stepper motor moves the pins in and out of the orifices in steps, in response to signals received from MCU. The motor has a range of 100 steps, but normally operates in the middle of its range.

When the metering pins are stepped into the orifices, the air/fuel mixture becomes richer. When the pins are stepped out of the orifices, the mixture becomes leaner.