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.