Re: ignition switch
Just because stuff doesn't work that is normally activated by the ignition switch doesn't mean the ignition switch is bad. Verify that it is actually bad and then replace it if necessary. It could be that the choke solenoid is bad or the wiring to it is open. The "M" terminals on the switch short the ignition the ground to kill the engine. Check the wiring first to make sure it's not the problem. As for the tach connection, it too can be wiring rather than the switch.
