So, like an idiot I didn't take pictures before taking my carb apart and I have a vacuum leak because I cannot for the life of me find out where this hose connects.  It's the black hose that comes off the left carb by the engine with a white connector.  It was connected when I took it apart but I cannot for the life of me figure out where it connects now.  I couldn't figure out how to get the images to show here so I just made an album in google photos. Sorry for that.

https://photos.app.goo.gl/RfPgDEGzSq4wxwVy9

I haven't had to deal with this so just guessing: Vacuum connection(s) besides the fuel selector valve is typically for emmissions controls, either the canister or valve(s).

There are diagrams in the Wiki that should help.

http://wiki.gstwins.com/index.php?n=Main.HoseRouting

Those pictures do not show the vacuum hose I am trying to find the home of.

what gs do you have? year?

https://www.pinterest.com/pin/27725353925737431/
Using the diagram for reference, identify the components for fuel/emissions control. 
First start with the unidentified line and follow it to its source.  If it is a tee, follow one line at a time and determine where each is going.  If one leads to another tee, try the other line.  Basically, follow the lines to get to an identifiable component to start from.

Starting from that component, follow one vacuum line and ensure it matches with the diagram to the next component, including the tees.  Mark each line physically and on the diagram.

Keep going until every line on the diagram is marked.