So my buddy and I were working on his GS last week and we're at the point we could install the carbs and airbox. But upon looking at the gaping hole that everything goes into, there was one hose that I just could not remember where it went to. We have the crank case breather hose accounted for, along with both fuel lines, the gas tank vent hose, the airbox breather hose, and the carb breather / vacuum hose.

The one I can't identify is pretty small in comparison to the others..... looks like maybe a battery vent hose, but I think that one is also accounted for.... maybe I'm wrong? Any idea from the masses?

Is this the one you're asking about?  And, are you asking where it routes to, or where it attaches to?  If the former,  this pic might help ya. If not, check info on the bottom of the page in this link : http://gs-500.info/index.php?title=Petcock_and_petrol_hose_routing

Thank you Sir.... but that's not the one. It does vent out the bottom (I didn't follow exactly where, but I can see it from above the swingarm), but the airbox drain hose is accounted for. The one I'm asking about is very small in diameter - maybe only 1/8" ID?

The smallest one will be the battery vent, next smallest gas tank overflow, and then the airbox drain with the cap.

 

"The one I can't identify is pretty small in comparison to the others..... looks like maybe a battery vent hose, but I think that one is also accounted for.... maybe I'm wrong? Any idea from the masses?"

Probably silly to ask,  but wouldn't the battery hose be pretty easy to fully rule out,  since ya got the seat off?  Is your hose in question clear?  Every battery drain hose I've seen so far that has came with the battery has always been clear.  Only other one that may come to mind would be the tank overflow.  Any luck with that hose description/diagram in the link?    And happy Thanksgiving to ya!  (i'm assuming you're from the US) haha.  My foreign friends always give me the strangest virtual looks when i jokingly wish them a Happy Thanksgiving.  Good luck bud

Sorry Sir, I could've sworn I replied to this....

Every other hose was accounted for, and the current battery is sealed - so even though the hose was black, it was the only option.

And thanks! Yep, Thanksgiving has come and gone.... which is a relief at times....ha.

sounds familia Big Rich http://gstwins.com/gsboard/index.php?topic=70286.msg844924#msg844924

Funnily enough only yesterday while doing some battery research I have figured out that the extra hose must be for the original battery drain hose on the right hand side and when someone put in a left hand side vented battery they left the old hose in place.