Downward gear engagement in which the input shaft and output shaft are locked together; the gearing in the drivetrain in which one turn of the crank shaft equals one turn of the wheel.
And ignition system that uses a distributor, electronically controlled or not.
A rod that connects the crankshaft to the piston enables the reciprocating motion of the piston to turn the crankshaft.
The starter drive gear that is attached to the starter motor armature and engages the gear teeth on the flywheel.