The reg/rect will not cause loss of spark! it charges the battery.
It is quite usual for the stator/rr connector to melt, eventually the resistance takes the rr out.
Solder the 3 wires and heatshrink tube over the joins.
Look at the fuse on the starter solenoid.
Take a lead from the battery and after disconnecting the coils, earth them and flick the live wire onto the coil feed terminal, it should spark at the plug/ht end.
Is the sidestand switch or clutch switch, if fitted, working?

would the stator make the bike not spark? managed to find another cdi off my mate for a fiver! i tried it with out the reg plugged in...
so you thinks its worth worth pulling the stator off and having a look?

Did you find out what the problem was?