so if you swap coils you get a spark at the rear but not the front?

if so than check your wiring to the coil and in particular if any wires got caught coming out of the stator when puting the left side cover on.

Craig

the starter is as much to do with it not firing.....the starter is ok if the bike fires up straight away....i replaced my starter for a new four pole permenant magnetic type to stop the drag on the battery, works well, but still doesn't engage well at times...

also battery needs to be good.....coils are linked with some other devices (starter relay, tacho, tci) so check all connections, if the bike has sat for a while during an engine rebuild..pull all the connectors apart and put them back...these are 30 years old....loose connections are common....