As these guys have already elaborated, there is a return spring for the pedal linkage in the floor. and there is also a heavy short spring on the starter contact button, mounted on top of the starter itself. that button is pushed by the pedal and linkage. the pedal may return but the button may not spring back, leaving the starter contact energized. Disconnect the battery and have someone push the starter pedal and watch the starter closely and see whats not springing back. The pedal linkage also controls the drive gear that turns the flywheel. Hope all this helps.
