Make sure the points are opening and closing. Make sure power is getting to the coils, check the resistor (it should be out of the loop while cranking to boost voltage, then be in circuit in Run to reduce coil heating. Just take the wiring diagram and trace through it, checking each junction for the ignition power on the bike. The Stop switch (right handlebar switches) is in RUN, right? In the Clymer manual, ignition troubleshooting starts on page 12. In the Honda manual, 16-4 (page 282 in my pdf copy). If you don't have these, you really need them. They are available for download on the 'net.