FINALLY...

THE NINJA HORN FIX! Big thanks to Al Weir from NZ for sending me over this little golden nugget of info. If only I’d had it six months ago... “As the mod on the Ninja400riders.com site, I need to inform you that your noise is in actual fact the horn. 9k rpm appears to produce the right resonance for the horn to activate. If you chuck a rubber washer in between the horn and the mount bracket that should see you right.”