Venting a gas tank

[SpaghettiOs]

I have split tanks on my build and set up a vent tube from the top of the second tank while the main tank has a vented cap... filled up the bike with no leaks 3 days ago, went to take it out today and as soon as I moved it the gas from both tanks dumped out from the vent tube on the second tank! needless to say there was a huge mess in the street now and I cant see what the problem is...

 

[angus67]

since you have a custom setup, how 'bout some picks?

 

[XSLeo]

A vent line between the two tanks shouldn't dump fuel, they are at the top of the tanks. usually above the fuel level.
Most have a crossover at the bottom of the tanks that link them together so fuel can transfer from one side to the other.
Perhaps you hooked your vent to this lower hose??
Leo