IVJ tenere ignition fail

[mushroom supersnake]

I have a 1989 IVJ tenere 600, & riding along at a hasty pace yesterday the engine just died on me. On checking, there appeared to be an occasional / weak / no spark at the plug. I have tried replacing the coil with another ( suspect) xt coil, but neither of them seem to want to produce a spark now.
i have checked for a pulse at the orange wire to the coil when kicking over, and the reading fluctuates from 0.25 at static to zero. when the ign switch is off this does'nt happen. when the stop switch is off it fluctuates when kicked over. is this correct ?

The stop switch is connected to a black ( earth ) & a blue and white wire that goes to the starter relay <?> which then goes to the cdi unit. Am i correct in saying that the switch needs to earth out the blue and white wire ( to the black ) in order for the engine to run ?

I have checked the two coils using a multimeter, and one of them reads 4.69 ohms the other reads 4.75 are these in tolerance / functional ?

I have looked everywhere for a wiring diagram in english for the IVJ and been unsuccessful

I understand that the IVJ doesn't need a battery to start, so no requirement for a test of 12v at the coil ( ? )
<there was no 12v on the orange wire>
Can anyone suggest any other specific checks I can run with a multimeter before i start swapping out the cdi etc.:confused1: