Petcock from z1ent

78 kz650 with an earlier tank. I replaced the vacuum petcock with the kit from z1 a plate with a threaded hole(3/8 I think) and a rubber gasket.

Any hints on how to install it so it doesn't leak fuel everywhere? Its horrific. I had to drill out the oval stock spot to allow the round new one to mount into the tank as it sticks up a bit, but the plate seems tapered so you cant thread the petcock all the way in, and overall I'm giving it a C- even if it didn't leak, which is sure does. What am I missing?

Thanks in advance 

Where is it leaking from? Have you try some kind of sealant like Teflon? Taper thread is probably NPT (National Pipe Thread) which have taper to it on both the fitting and the thread side of it.

If it's leaking from somewhere else, can't you just return it to get a replacement?

I tried a fuel proof gasket maker. It seems to be leaking down the bolt threads but it's hard to tell with gas.

I'll trY some thread tape

years ago a petcock with eliptical o ring between it and the tank leaked when gasoline eventually dissolved the POs paint between o ring and the tank metal. sanded off the paint and all was well.

It's hard to find gas "proof " gasket maker. Gas resistant is more the norm.

If trying thread tape I've read that the white stuff is not good and that the yellow for natural gas fittings may be better. Think I picked up some at home depot but have not used it

It's funny you say that. So I read the label on the natural gas thread tape I had and it says it's good for gasoline. I used it on the bolts and the petcock and no sealant of any kind on the gasket. Previous attempt I used sealer on all of the above.... results sucked. I also sanded down  the mounting surface thinking the same as you described. If it still leaks I'll try a small amount of a second sealer I got that says it's good for gas. But just a smear on the tank side of the gasket. After that I give up and carry a Jerry can in a back pack. 

Thanks for the reply

so the thread tape seems to have worked on the threaded petcock and the mounting bolts, but the rubber gasket leaks still. Plan B is to try the second type of sealant I picked up.... argh

Im talking to myself at this point. lol. So I bought a sheet of Klingersil C-4401 gasket material. I notice that Z1 is no longer including the crappy rubber gasket that they sent me, but one made of this stuff. It appears to be the new magic material. its about 25 bucks or so for a 20" x 20" sheet of 1/16" thick gasket. 

 

Hope it works for you. Let us know