2011 Te449 Fuel Overflow

Hey guys,

Got a big issue here, preventing me from riding.. happened twice already. In the attached video (
View: https://www.youtube.com/watch?v=hEBQhEsMjBg
) you can see fuel dripping out quite heavily from the overflow line, however, when I take the gas tank cap off it stops. My guess is it's something to do with some sort of vacuum effect. Could this be the case if the gas tank cap (silly plastic one) has warped due to heat?

Where should I start looking to fix this issue? Any hints are greatly appreciated!

Thanks in advance!

There's a thread bout this te449 gas tank breather vent under 4 stroke Italy common issue the one way valve is either clogged broken or missing. You'll find the thread bout 10 posts below yours. Good luck

Thanks @Teambowles!