Fuel petcock/fuel overflow

Hi guys,

Anyone know how tight the petcock should be secured on a 1975 Z1-B? I have discovered that if you over-tighten the petcock, you will crush or distort the ring seal. On the other hand, if you do not securely tighten the petcock to the tank, it will leak.

The petcock does not bolt to the tank, the petcock has a threaded sleeve that threads directly onto a threaded bung on the under side of the fuel tank. Any ideas?

Thank you all in advance

It has a reverse thread on one side. With a new seal or O ring, you get it where you want it then tighten it.
Steve

I would install a new o-ring & put teflon tape on the threads, then tighten it snug by feel.
assuming the t. tape won't interfere w the o-ring.