how did it turn off ?

[tommyardin]

Weird!

I had mine cut out once, but that was due to a faulty kill switch.

It's possible that you had turned the key enough to complete the ECU circuit, but without it "locking" in place and maybe the vibration jiggled it back until it switched off, but that's just a guess.

Try operating the key a few times and see if it feels sticky or moves too easily.

If all else fails, you might have to replace it.

I am assuming that the ignition/key switch is on the top steering yoke as it is with the FZS.
Do you by any chance have a largish key fob on the keys and could be possible for the fob to be slapping about especially at high speeds or under hard acceleration to slowly turn the key? don't know if it is possible but just a thought, anyway fobs that thrash about whilst riding mark the paint or finish on the top yoke.  :rolleyes