Bike carb issues bandit 400?

i'm rebuildind a 91 gsf400 for my girlfriend and i'm in a bit in a fog, the bike will start breifly and run for about 5 seconds, then it will die, i have kept it running via the spray in carb cleaner method, but it has to be sprayed in the entire time as soon as i stop spraying it goes 1,2,3 dead, any ideas|||1st, make sure your fuel tank is properly vented because a non-vented fuel tank will stop fuel flow. Next, remove the shuttoff valve on the bottom of the gas tank, take it apart and clean it out. Sounds like it's possibly clogged (there is a screen inside of it), or the needle valve in the carb is stuck closed and not letting fuel to enter the float bowl. That's all I have to suggest, but it should be one of those scenarios.