Airbox hose question

[Anonymous]

I have a 1979 GS550 L, and took the tank off to de-rust it. I got the issue of the hoses from the tank to the carbs figured out (thanks to the 10+ posts and helpful pics), but on the bottom (front) of the airbox, I have a rather thick hose that snakes its way up and comes out right around where the carbs go into the airbox. The hose looks as if you could fit a slightly smaller diameter hose into it (for example, the carb vent hoses would fit into it) but I'm not sure what is supposed to go in it, if anything. Thanks.

[Jethro]

Not sure if yours is the same as my 81 and 83, but there is a drain at the very bottom of the airbox in case the sending unit gasket leaks on the tank, or the floats overflow and gas pours out of the carb throats as well as the float bowl overflows.

[Anonymous]

Well, the hose is kind of on the top front of the lower airbox (make any sense?), so it doesn't seem like it would be a drain.

[Jethro]

It could be the place where your crankcase vent is supposed to attach. Are you familier with the crankcase vent? It runs from the very top of the valve cover to the airbox.

[Anonymous]

Not familiar with that. My Haynes manual doesn't mention that. Well, at least it's not in the chapter where I would expect to find it, and it's not in the index. Would that hose just slide into the one coming off the airbox?

[Anonymous]

Ok, my mistake. It does come off of the airbox on the bottom front. The plastic part that is part of the airbox (which the hose is connected to) comes off the airbox at an angle, from left to right (if seated on the bike), and is on the lefthand side of the bottom of the airbox. Is this the drain? If so, for some reason, on my recently purchased bike, the hose is snaked up through the frame, and pointed upwards. It comes out right below where the seat and petrol gas tank meet. I assume that it should be hanging down so that the fuel can drain in the event of an overflow.