1978 KZ650C Petcock Leak

I've run into a bit of a pickle. I've got a leak coming from the petcock. I pulled it apart and found the culprit. So I think, "I'll just get a rebuild kit and slap that thing together." I've searched far and wide and I cannot find the specific kit that will fit this petcock, which makes me think this is not an original petcock. Does anyone else have this same style of petcock with that diaphragm that has that pin hole? If I can't get a new one, is there anything that I can use to patch it with that the fuel won't just eat through? Are there any other petcocks that I can get that are a direct bolt on? Thanks in advance! Apparently my pictures are too big to attach but I'll link the pictures in dropbox.
www.dropbox.com/s/jdbrmxqb1ja2y0n/20160308_205002_HDR.jpg?dl=0
www.dropbox.com/s/uleatt9d354i9m2/20160308_205031.jpg?dl=0
www.dropbox.com/s/h5f6j0jskmy85z7/20160308_205059.jpg?dl=0

Your bike has the so-called hat diaphragm. I'm not sure if there's anything available to replace it.
There's a pretty good topic about it over at the KZ650.Info site, but I couldn't find it.

The bolt-hole spacing of your stock petcock should be 44mm. Z1Enterprises.com may have an aftermarket Suzuki vacuum petcock that will fit. KZR search = Dr. Suzuki by gargantuchet (sp?). I think most of the pics are gone, though.

You could install a manual fuel valve. search eebbaayy for yamaha raptor fuel valve 44mm or something like that.
super cheap are available, but I would get the made in Japan Yamaha part. ~$30. they come in a couple of versions, depending upon the year range.

stuff to check on a replacement: bolt hole spacing. fuel port OD. main pickup tube length. extension below tank --- some are tucked up close to the tank, while others hang down some. and might contact the carb top. ??? or just go by the bolt spacing & don't worry about that other stuff.

Well that's not the news I wanted to hear! So the best route is to toss this one and buy new? I guess I'll bite the bullet and do that. Maybe it's an unpopular opinion but I actually really like vacuum petcocks. I'll search around for one and let you know what I find. Thanks again!

I like them too as long as they work.
Steve

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You could install a manual fuel valve. search eebbaayy for yamaha raptor fuel valve [strike]44mm [/strike]or something like that.
super cheap are available, but I would get the made in Japan Yamaha part. ~$30. they come in a couple of versions, depending upon the year range. ...

Correction. I think the yamaha raptor fuel valve has a 34mm bole hole spacing. not sure if yamaha has one in 44mm.

I use this Suzuki vacuum petcock on my 650c2.
The fuel feed is towards the back, so a longer fuel line is needed to route the fuel.

www.z1enterprises.com/product/KL18-4359

For a 78 650C all you need is a 77 manual petcock direct bolt in, outlet same location looks just like stock
Have had this on my 78SR since 1983 when i tired of fixing the piece of junk vacuum stock one,was turned on to this by an old
Kaw racer/mechanic, Since then I have changed over 7 bikes(several 78650C's) with no problems. When I see a 76-77 manual petcock on ebay I buy it for future use :ohmy: Have yet to see a vacuum petcock worth a damn and it's just getting worse with the fuel blends being sold nowadays