Petcocks Problems, KZ1000-K2 and KZ650

So I picked up a 1982 KZ1000-K2 LTD. When I went to drain the gas, the petcock leaked when set to PRI, so I figured I'd pick up a rebuild kit. How hard can it be?
Well, I put the rebuild kit in, mounted the petcock to the tank and now fuel flows from every position...ON, RES, PRI. I've had it apart five or six times, making sure I didn't do anything wrong, with the same result. Am I missing something here? The plunger on the petcock has an o'ring on the end of it where the plunger inserts in the petcock. Is there another o'ring somewhere that I'm missing (not the one around the handle)? I've had problems with KZ650 petcocks in the past as well, and they seem to be the same as this KZ1000. Even the Suzuki petcock that I bought (new) while back does the same thing; leaks on all settings. Any help is appreciated; I know petcocks have been discussed before, I'm just frustrated, and thought maybe there's something obvious I'm missing. Thanks for your help.

What rebuild kit is it?
Is the diaphragm installed onto the diaphragm plate correctly?
Spring installed between diaphragm assy & diaphragm cover? It's part #92081-1171 SPRING,TAP in the diagrams at Partzilla.
Only other thing I can think of is maybe the petcock body has corrosion at the plunger o-ring mating surface.
Or the kit is wrong or something >> maybe the wrong plunger o-ring?

OK, got the kit from Z1 (Mike's), all parts look exactly the same. Threaded the rubber diaphragm through plastic spacer, spring on top of round disc, butting up against inside of diaphragm cover. Plunger has oring on end, pressed into body of petcock. Screwed down cover. On opposite side, removed 2 screws from plate, removed plate, wave washer and handle. Removed round disc, replaced with new one, replaced oring around handle, wave washer, pressed handle into place. Replaced screws. Mounted to tank, added gas (over a bucket, fortunately). As it filled, gas began pouring out on ON, PRI and RES. Please tell me what I missed!

Couple pictures of what I have here.

Are the plunger & o-ring the correct size. Maybe it's just the perspective, but they look smaller than the orifice. ???
Maybe the o-ring isn't sealing properly, for whatever reason. ???

I recently had a problem with my '77 KZ-1000 petcock. It's different than yours, but the hard part was trying to figure out where fuel was leaking because it just runs all over. As it turned out, my problem was where the petcock threaded onto the fuel tank. Yours apparently is attached with 2 screws to the fuel tank. From the Kawasaki parts diagram it looks like there is supposed to be an o-ring between the petcock and the fuel tank. Is that o-ring in place and does it have a really clean surface to seal the petcock to the tank? I am not sure, but that o-ring may be rectangular in shape and not a circle, but I have never taken one of those apart. I also noticed in the parts diagram that there were two different types of diaphragms available for some reason. Don't know if any of this helps, but what the heck....
Rick H.

Yeah, the o'ring to the tank is fine. The fuel is pouring out the petcock tank outlet. I hate spending money on $100 petcocks, but a Pingel manual is looking better and better to me. This seems to be an old KZ weak point.