the second small terminal is for ignition power to coil when starter is cranking.the solenoids are available in 12 volt if desired. this type of solenoid is only an eletric swith and will have no effect on how hard the drive teeth hit the flywheel.the force of drive gear hitting the flywheel is from the 6 volt starter being run on 12 volt roughly spinning twice as fast as normal when it contacts flywheel teeth.