Fuel leaking out of vent

[96TL]

My friend has a 2005 2520. Whenever he's fueling up, a small stream of fuel dribbles out of the vent and runs down his hull directly into the water! We pulled the vent apart today and it appeared to be clean. He said it just started doing that last season. Any idea where to what to do? Thanks guys.

Here's a pic of the vent.

 

[chrisn]

Sometimes if the fuel is coming in contact with the cap chain fitting it can spill through. Other then that it is also an overflow that will purge if the fuel backwashes the piping. This CAN occur sometimes if it is a high flow pump. When i fill up i listen for the fuel coming up the pipe...then i am full. I almost always have a little dribble.