I would check the ground. If you are getting 12v to the points and the coil, but no spark out the hi voltage end of the coil, it's either the coil, the wires, or it's not going to ground. Also, make sure you are using a brand new plug, not a cleaned up old one.
Cool bike btw. My wifes 1st was a Honda Trail 90. Mine was a Trail 70.
