Join Date: Apr 2010
Location: The Little Apple
That is the bowl vent tube. You can run a length of fuel-grade tubing from there to your canister. Your canister should have a port labeled "bowl vent" or "carb vent" or something like that.
Yours is spewing fuel out of it because...well, it's not supposed to be spewing fuel. How much fuel are we talking about? During operation, i.e. when you are running, that port should be closed; it opens a bit after you've shut down. If you look closely, you'll notice a mechanical linkage in that photo that closes a valve during drive time. Once shut down, it mainly carries vapors which are stored in the canister. If fuel is coming out of it, you've got something going on in your carb - either your floats are too high, or you've got some sort of back pressure/high fore pressure issue, i.e. you don't have a fuel return line from your filter (you should have two coming off your filter, one that goes to the carb, one that goes to the fuel return line back to your tank), or you are kicking out a ton of pressure from your pump. Probably more likely is that the mechanical linkage (I believe there may be a non-mech version out there, too) is not working right. That's about all I've got.
I suggest you either a) run a line from there to your canister or b) cap it until you figure out why raw fuel is coming out.