What is the role of a starter motor in an engine?

The role of a starter motor is to initiate the engine's operation by turning the crankshaft. When starting an engine, the starter motor engages with the flywheel connected to the crankshaft, providing the necessary torque to rotate the crankshaft and begin the engine's internal processes. This action is crucial because, without the initial rotation, the engine's fuel-air mixture would not be compressed properly in the cylinders, and ignition could not occur. The starter motor allows for the transition from a non-operational state to the operational state of the engine, making it a vital component in the starting system.

While enhancing fuel combustion, monitoring engine performance, and controlling emissions are important aspects of engine operation, they occur after the engine has been started and are not the function of the starter motor itself.