TOPIC:

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That bolt spacing looks to be about 45 mm? Looks a lot like the one on my ZN1300. I've been looking for a replacement tap screen without any success - maybe replacing the entire tap is a better option?
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44mm. For a complete petcock, possible fitment is the KZ1000P police petcock. Its spacing might be 44mm, but I have not confirmed that.
The 1000P petcock is still available at the dealer, and some of the on-line places list it for around $65 or so.

Just an update to see if anyone has any comments/suggestions . . .

I re-assembled my old petcock, with the "top-hat" diaphragm, using parts from the rebuild kit, including the new o-ring that goes around the handle, the "4-hole" gasket that goes under the handle, and the tank-to-petcock interface o-ring. Couldn't use the new style diaphragm that came with the rebuild kit. Reassembled the "sandwich" with some gasoline proof gasket maker between the layers (since my original issue was a leak from the sandwich portion of the petcock). Put it on the bike and it seems to be functioning perfectly (gas stops flowing when vacuum is not applied). However, the next day I noticed I had a slight leak on the petcock-to-tank interface with the new o-ring. Didn't know for sure if that was really the correct o-ring, since the one in the kit was round, but the one that came off the bike was oblong. So I swapped back to the old one and that seemed to do the trick . . . for about a week. Now I have a seep again from that interface. So I guess my next step would be to order a new o-ring for that interface? Or did I get the correct one with the rebuild kit and I'm just peeing in the wind? The part numbers match up so I'm guessing I already have the correct o-ring, even though it's circular instead of oblong. And it's a 40 year old bike, maybe it's just the nature of the beast! TIA

Ron

What does the mating surface on the tank look like? I'm thinking maybe it just needs some light sanding.
If the new o-ring fits into the groove & it's the same thickness as the old one, then it should be good to use.
Alternatively, you might try a thicker o-ring from a metric o-ring kit. When I changed out the o-ring on mine, there were a couple of sizes that would work. Fitting a round o-ring into an oblong groove can be done. It's a bit fiddly, but it can be done.

WhatI did was to cancel out the gas floating system and put the 34mm petcock in that hole. Then I soldered the remaining useless hole. #aintnobodygottimefothat . I wont pay 85 dollars for that "police petcock" when I already had in my hands the 25$ solution