The tachometer works according to the magnetic principle, receiving the pulse signal generated when the primary current in the ignition coil is interrupted and converting this signal into a displayable RPM value.
The tachometer's numbers are only about 1 to 8, with the pointer to the number multiplied by 1000 is the engine speed, the tachometer can visually display the engine's rotational speed in various working conditions, the owner can always know the engine's running condition, grasp the timing of the gear shift to match the gears and the gas pedal position, so as to keep it in the best working condition, to reduce fuel consumption, and to prolong the life of the engine.