Derating an engine or motor is either the intentional or unintentional reduction of total power that an engine can produce in ideal conditions. Intentional derating can be achieved through mechanical or electronic means. Putting in smaller carburetor jets to limit fuel flow is one such method of mechanical derating. Derating can be accomplished electronically by mapping a lower tune into the electronic control unit. Unintentional derating is usually caused by wear and tear on an engine which results in a reduction of power.