Interesting fault, simply lift the seat to fix !!! i reckon as i was carrying a pillion on the day of the alleged fault in question, that his lardiness had caused a wire to earth / become dissconnected / trapped and lifting the seat and checking all the block connectors seems to have fixed the problem (for now i suspect)
So when i get some room and have put the NC30 back in the house and the motor back in the TZR chassis i will strip the 916 and check and clean all earths, and contact clean all block connectors etc etc to avoid a repeat performance next time some lard arse pillion is being propelled though the air faster than their body should !!!