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The only problem with this is that if I don't crank my Chopper within a week of the last ride, the system looses vacuum....

Worked great except when the bike sat for a few days it would loose it's prime ....

It should loose prime instantly, shouldn't it.

This new fuel valve shuts off the flow of fuel to the carburetor automatically whenever the engine shuts off....

The engine should start with the gas that is already in the carb.
I guess I'm not understanding what's going on. The petcock should loose vacuum everytime the engine is shut off, there's no check valve installed. If it held vacuum for almost a week the petcock would be open all the time. I don't see any reason it would hold a vacuum for days, or not pull a vacuum as soon as you cranked the engine over.
There should already be fuel in the bowls for the squirters to spray into the motor, or does it evaporate that quick? Maybe that's what's happening, no fuel for the squirters.

That's exactly what's happening Elvis. With my bike, the evaporation took 6 days.

I'm not sure why we're not getting enough vacuum with the choppers. May be intake related. I wish Dave Ward or Neil would chime in here as they told me once but specifics evade me.

Els

When I was experimenting with the vacuum fuel shut off valve for the first time I was on vacation in Florida for 3 weeks including the week before bike week , bike week and the week after bike week . As long as I rode the bike everyday which I did for the first 2 weeks it didn't loose it's prime but when the third week came around there were a few times the bike sat out in the sun for a couple of days at a time with my cover on it which I think helped with the evaporation process of the gas in the bowl . After it sat for a couple of days like this it lost it's prime I assume because it wouldn't start until I sucked on the vacuum valve hose . Then it would fire right up .

Jack