The fuel tap on mine has been chemical puttied back together and did nothing except let the fuel through. Better than not letting it flow I suppose.
Anyway, I wanted a functioning fuel tap with a reserve setting. I couldn't find one with a big enough outlet, that faced the correct way and had the correct thread so I settled on the fuel outlet.
The outlet spigot on the tank is M18 x 1mm and the replacement tap, from a CBR600 year unknown, has a female M22 x 1mm theread.
So this got made:
The tap now fits the tank, I just need to refit the tank to see if it fits the bodywork.
Back soon.