Fuel Tap Assy

I'm currently going thru my gas tank and want to renew the fuel shut off valve parts. Does anyone know what the vacuum requirements are to open the diaphragm? I'd like to check it while it's on the bench.

1979 KZ1000 MKII

It is usually just intake vacuum from off the carb holder, or carb itself. Doesnt take very much pressure, just a slight suck on an attached hose and it will open the diaphram easy.

There are no specifications for amount of vacuum from Kawasaki.

Good luck.

THR I don't know the specific number to open it, but your motor should be pulling upward of 20"hg at idle so just try that. It shouldn't take very much vacuum to open it at all. What causes them to fail is leaks in the diaphragm, or leaky seals that prevent it from shutting off. Just hook up your vacuum pump and get a little vacuum on it, and see if it will hold the vacuum. If not then rebuild it or replace it. Our ethanol "enhanced" fuel is awfully hard on all the rubber parts in a vacuum petcock these days.

Maybe someone with specific knowledge will see your post to give you an exact number. My testing method has always worked for me.