Great to have found this owners club - lots of useful info to be read

I have just bought a KZ1000 and the only annoying thing about it is a loud ticking noise which is apparently coming from the fuel tap

I've done the old trick of touching one end of a long screwdriver onto the engine, and the other too my ear and it's definately coming from the tap and resonating through the petrol tank.
Can anyone suggest what this ticking may be please?
Many thanks, Mike