[pinheadplanet]

You need to leave your thumb on it for a few seconds until it will turn, before that there's just nothing.

I checked the wiring in the back of the button and all seems ok, so what next?

Cheers

 

[graeme.medley]

Does the solenoid 'click' as soon as you press the starter button?
Or does that happen after a few seconds too?

 

[pinheadplanet]

No 'click' just nothing.

 

[Doug Hyde]

Dirty contacts on the switch? Doesn't cost anything to check or rectify. Might be a pain to check IDK, I've never taken a ZR's switchgear apart.

 

[pinheadplanet]

I already took the switch apart, didn't seem to be any issues.

 

[graeme.medley]

Check for 12volts at the starter solenoid (behind the rhs side panel)
one of the heavy duty terminals should be 12v at all times, the other only live when starter button pressed.
The lighter duty contact should receive 12Volts when starter button is pressed.

Remember that there are interlocks on the starter circuit.
It should start in neutral with the clutch out and stand down, but pull the clutch in to double check that switch.

You could, if you have the bike on the centre stand, hot-wire the starter solenoid.
That will by-pass all the interlocks, if it still does nothing then either your solenoid or the starter has failed.