KZ1000P petcock on XS650SK?

[Fusion]

Would a KZ1000P petcock fit an 1983 XS650?

https://ebay.to/2O17kwc

The mounting holes on the KZ unit are 44mm, while (I think) the XS650's are 46. If need be can I dremel it out?

This thread https://www.xjbikes.com/forums/threads/rebuilding-the-yamaha-vacuum-fuel-valve-w-pics.25058/
shows a picture of a near-identical unit (HCP626). Notable difference in positioning of fuel/vacuum ports. But that's just looks

The impetus is that KZ1000P's are plentiful, good luck finding a new vacuum petcock for an 80's XS650

 

[grizld1]

Right, XS650 vacuum petcocks have 46 mm. centers. Your main problem would be that the petcock mounting holes are open to fuel. You'd wind up with the petcock holes ovaled or screws offcenter in larger round holes, and I have no idea how you'd go about getting a seal without welding the old holes in the petcocks shut and drilling new ones, and then there's the question of whether you'd have enough flange surface left for a seal at the edge.

 

[Fusion]

OK, so those mounting holes participate in the seal... that is a game changer right there. I was thinking the mount holes in the tank itself were actually sealed already, but I guess not.