I did away with the vacuum one and replaced it with a Pingel fuel valve.Cap off the T connector where the vacuum line went and that's it.I didn't mess with the VOES switch.
Mines a 99 but I don't know when they started using vacuum operated petcocks.And I've always turned the gas off whenever the bike wasn't running.Just a habit since day one.

 

The '96 still had the VOES.

 

I have a 95 and it has the vacuum fuel petcock.