Thanks I'm pretty happy with how it turned out. Now just need to work on a mount setup. My buddy called me and explained how his works on his Husaberg.
It's just a simple vent that he tees into the regular vent coming off his gas cap.
I looked inside the Ninja tank and there is a metal straw than runs internally and exits the bottom of the tank as an overflow like Sanjoh said.
I can make up a barb setup and zip tie it to the straw in there.
I just bought a bunch of gasoline grade barbs and tubing from McMaster to add to the fancy ass AN racing stuff.
We're not out here to rough it. We're here to smooth it. Things are rough enough in town.