hey all,\nI have a 1975 gs450l. I have replaced the starter solenoid, stator, signal generator, battery, TR. Igniter box, coils, boots and wires, and spark plugs. when I turn the key the headlight and brake lights don't come on and the bike won't start. anyone have any ideas? the starter turns the motor over and you can hear the motor trying to start but I am not getting a spark. I have also cleaned the carburateurs and the fuel pitcock. I replaced the fuel line, vent tube, and vacuum lines.