Modern Vespa

My fuel tap was not shutting off. I installed a new packing rubber. It did not fix it.
Do I need to just buy a new fuel tap?

By the packing rubber, do you mean the piece that goes inside the valve itself? If so, you might check to make sure it's installed the right way. If it isn't, it might be allowing fuel to flow when it's supposed to be off, and not allowing fuel to flow in another position (such as reserve). Maybe post some pics so we can have a closer look?

Yes the one in side, part #13836 - Fuel comes stright out the fuel line port will not shut off. Moved it 180 still the same?
Sorry no picture

If the vent tube has come out or if the fuel level is over the vent tube level, the fuel will not shut off.
PS. if you end up replacint the tap. you wiil need to enlarge the hole in the bottom f the tank to fit the tap.

Tank is empty, puting in a small amount of gas at a time just to check it - vent tube is in. I will look to see if it may have a hole down low on it.

Dammit! I thought we were talking about Old Style

I think I could use a old style about now.
Took it out and yes it had like a stress crack, 1/2 way around.
My have been hit many times with the gas pump nozzle?
Thanks, Benson