History: The ZX9 has been getting harder to start, particularly as the fuel level drops. Occasionally, even after a fill-up, it needs a push start - and that's mostly on hot days. I put it down to vapourlock or possibly fouled plugs, which are about due for a replacement. Now: As of last night, pressing the starter button does bugger-all except sometimes make a fast clicking noise from somewhere toward the rear of the bike (a relay?) Bike starts easily if roll-started. Any ideas what to start looking at with this problem? Push starting massive old litrebikes is excellent exercise but it's beginning to impact upon personal dignity.