Suddenly no spark

[bikerphil]

I would try running full voltage from the battery (+) directly to the coils (red/wht), then see if it fires/check for spark.

[James England]

I had similar problems and found it was one of the block connectors in the headlamp (square type headlamp). There's not much room in there and putting the headlamp back in dislodged it slightly. Everything on the bike worked except the ignition... intermittently. I replaced the block connector entirely.

Also, I'd have a look at the two block connectors which connect the right hand side handlebar switches to the wiring harness. One of them connects the starter button and kill switch. Mine was in a poor condition and was intermittently disconnecting, killing the engine and/or making the starter button not work. Again, I replaced the block connector completely