Starters are electric motors used to mechanically rotate the internal combustion engine to initiate the combustion process. Typically mounted to the engine block or bellhousing, they engage with the flywheel ring gear via a pinion gear. Current starters utilize a solenoid to extend the pinion and simultaneously engage the motor circuit. Modern units often incorporate pre-engaged designs for reduced ring gear wear and improved starting reliability. Output is specified in horsepower and voltage, with amperage draw a critical performance parameter.