HELP gpx 250 fuel issue

Hey guys, could be the amount of beers I have had tonight, but I thought fuel came out of the tank to the carbs?

Im working on a chugging problem my girlfriends gpx 250 has developed. Noticed no fuel was getting to the inline fuel filter bellow the fuel tap. I took the tap part off the tank, I can blow into the pipe with a bit of force and get air through, but i cant suck air from the tank side to the tap side.
Am I doing something wrong here?
Am I not seeing something?
Am I too drunk?
What purpose does the diaphragm serve inside the tap?

I thought when the tap was on, fuel flowed freely from the tank?

Hi,

Not sure if the GPX is the same as my GPZ but my bike works on a vacuum system which has a breather near the fuel filler. If that breather gets blocked fuel wont flow.

Worth a look I guess but some of the GPX owners probably have a better idea.

Cheers,
Wayne

Probably jsut a bad batch of fuel. Empty out the tank and put some fresh petrol in, but not from the same servo for now.

If that breather gets blocked fuel wont flow.
Cheers,
Wayne

I second that. Seen it happen a few times. If your breather is blocked it creates a vacuum inside the tank, stopping the fuel from flowing. Easiest way to chick it is to just have the fuel cap open, if fuel flows and then stops after you close the cap (won't stop istantly) it's a breather issue. It's the same princible to putting your finger over the top of a straw and pulling it out of your drink (get your Mrs to try it coz blokes don't use straws) the liquid will stay in the straw.

yeah they are vacuum, so as wayne and stace have said, might have a blockage