Re: Ignition Switch
Before you disassemble the starter (not saying I did), disconnect and clean all the connections from battery to solenoid to starter. Especially the solenoid. I mean, make 'em shine. I use a dremel with a stainless steel wire brush. Reconnect, I mean tight! and try again.
The powerpack is completely separate from the cranking circuit.
The main fuse is in an inline holder on the red wire leading from the solenoid to the main wiring harness plug. If the push-to-choke works, you know the fuse is good but check it anyway, sometimes corrosion in a fuse-holder does funny things.
If you have a multimeter, set it to DCV, touch the red probe to the battery (+) and the black to battery (-), should be neighborhood of 12.7 volts, that is your battery open-circuit voltage. Then move the red probe to the solenoid large terminal (cable leads to battery), and the black to the engine block. If you don't get within .1 volts of battery open-circuit voltage, there's a problem in the battery cables, could be where the batt (-) is attached to engine block.
Next move the red probe to the small solenoid terminal with the yellow/red wire attached (black probe still on engine block) and have someone turn the key over to "start". If you don't get within ? volt or so of battery open circuit voltage, there's a wiring problem between the keyswitch and solenoid.
Test the keyswitch: red probe on terminal "B" and black on terminal "M" (black wire, not the terminal "M" with the black/yellow wire) - if you don't get within ?volt of the battery voltage, either the red or black wires are faulty or connections are bad. Careful what you touch in there with the battery still connected.
Assuming good voltage at the keyswitch: disconnect the battery. Set your multimeter to "continuity". With one probe on terminal "B", the other on "S" and the key turned to "start", a tone should sound, otherwise the keyswitch is faulty. Test the neutral safety switch: touch one probe to each of the two terminals on the switch, with the shifter in neutral a tone should sound, otherwise the switch is faulty, or has shifted to where the shift lever isn't holding it closed.
If you have good voltage at the small solenoid terminal and the solenoid doesn't make an audible "click when the key is turned to start, the solenoid is faulty. (Assuming you cleaned and tightened both of the small solenoid terminals and the black ground wire connection to engine block.)
The kill switch has nothing to do with the starting circuit, but to test it, touch one prob of the continuity meter to each of the two terminals; with the lanyard attached (run position) should be open circuit (no tone, infinity resistance); lanyard detached (kill position) should have continuity (tone sounds, minimal ohms).
If you don't have a multimeter, wallymart sells an autoranging digital for about $25, not the best but good enough. Will come in handy around the house.
p.s., when measuring resistance (ohms) or continuity, if you touch the metal part of both probes, it'll display the resistance of your body, which makes the reading irrelevant to what you are trying to measure. If you get nervous, your resistance will drop, so always tell the truth when holding an ohmmeter.
almost forgot, if you get less than 12.6 volts across the battery terminals, charge the battery, or use a different, known-good fully charged battery for your tests.
