You should be able to produce a spark manually. With the cap off, connect a spark plug to the coil using a plug wire. Lay it on a metal surface. With the points open, turn on the ignition and short across the points with a screw driver, momentarily. That should produce a spark.
When I am trying to bring an old motor back to life, I power the coil separately with a trickle charger. That way the ignition gets full voltage while the starter is cranking and after it starts.
