Tacho over-revving ZZR250

[Filmer]

My tacho is telling me that my bike is revving about twice as much as what it actually revving.
I first noticed it after riding in heavy rain (don't know if that contributed to it or just a coincidence)
Any ideas of what could be causing the problem??

[disenfranchised]

My wife's ZZR does something similar....on a very intermittent basis, it'll breifly read twice as much, or nothing at all.

Might be related to being wet.
She's had it looked at, but being intermittent they couldn't find an obvious cause.
I think they cleaned the connections and it stayed right for a while...has just started up again.

So I'll be very interested in an answer too.