Petcock leaking - 1977 KZ650

Hello

I have been having an issue with my petcock leaking very slowly but enough to cause issues.

It’s not leaking from the selector knob but rather from the outlet pipe even when the selector is in “off” mode. 

My assumption is that the plastic piece inside the petcock is not quite holding the seal. Does anyone have any other suggestions of things to look for or ways to fix the issue ?

Thanks in advance 

Time for a new petcock.  Check the bolt center to center spacing, then I'd go hunting on ebay.

If it is the stock non-vacuum powered petcock there is not much to it, see attached pic.  I have read of others using something like toothpaste to lap in so to speak that tapered plastic item and the port it fits into. Do not know if that will help or not?

It may be dirty inside.  I would disassemble it, carefully clean it, and put it back on to see if it still leaks.  Ed

They are not hard to rebuild. Some attention to detail will get you smooth, leak-free, petcock. Here is a tutorial for rebuilding them. It is for Yamaha petcocks but the Kawasaki ones are similar.
How to rebuild vacuum operated petcocks

Thanks for the tips. 

it is indeed the non-vacuum version and the culprit is likely that little piece of conical plastic. I will try cleaning everything with my ultrasonic cleaner and hope for the best. Does anyone make that plastic piece, Z1 doesn’t seem to carry them. 

Thanks

Looks like a project for somebody with a 3D printer…….

Do you happen to know of such a person?  

Give Pete a call. He makes some interesting stuff for the ZRX and a few other bikes. He might be interested in giving this a try if he has the time and if he could sell a few. I have bought from him several times and it has always been a great experience, and he likes to talk to enthusiasts.

www.kwick.biz/contact/

I don't know anyone who makes them.  They come up for sale occasionally on ebay as OEM parts.  Alternatively you might be able to find them from the company that makes the cheap replicas.

I am looking into finding a 3d printer or shop that can make it.