Easiest way to test for voltage at start and run is to connect a voltmeter to the coil plus side and engine as ground.
Turn key to run position, should have 9 to 11 or so volts engine off, then thrn key to start, should have battery voltage at plus terminal.
If there isn't spark at start, but you have voltage at run, look to the wire from the solenoid to coil plus as either broken or disconnected.
Let us know what you find on the voltage. Could also be dirty points, dead coil, etc, the usual suspects.