KZ 900 Petcock

I have a 1976 KZ 900 that has a petcock on it with 2 fuel outlets. The bike has Mikuni 29 mm carbs on it, which only have one fuel input. The petcock is leaking fuel. I have made sure that everything it tight on the petcock. Can anyone tell me where I can either get a rebuild kit for it or a petcock with only one fuel output ? Thanks in advance.

www.z1enterprises.com/ItemDetails.aspx?i...1100A&item=KL18-2712

www.z1enterprises.com/ItemDetails.aspx?i...UTLET&item=SU009-302