Loose hose on my motorcycle, help!
 

I came home from work Friday and noticed a very strange hose dangling loosely from my bike, down on the left side by the kickstand. I just bought the bike about a month ago, and I'm certain that this must have come off very recently.

The problem is, I have no fucking clue what this hose goes to. It's dangling loose with an open end, and the end doesn't look sheared off at all. About half way down the hose is a little T joint with hose clips, but I'm not sure why. The bike starts and idles just fine, and everything looks okay. With the bike running, no fluid at all seems to come out.

Coolant level is right where it should be, front and rear brake seem to work just fine, clutch engages/disengages, it'll shift up and down.

I tried to take the seat off to get a better look at the other end of the hose, but I couldn't seem to break loose the back bolt.

The hose in question:
http://img393.imageshack.us/img393/6474/image042vx5.jpg

The end looks cleanly disconnected, not broken, sheared or cut...
http://img116.imageshack.us/img116/8828/image043du1.jpg

The mysterious "T"
http://img116.imageshack.us/img116/9830/image045jk4.jpg

In the center of the picture, that black plastic sheath that a hose comes out of, that's this hose.. I can't see where that sheath goes.
http://img142.imageshack.us/img142/3896/image046pq6.jpg

Coolant looks fine:
http://img142.imageshack.us/img142/3647/image048eq4.jpg

What could this be for? And why would it pop off?

The bike is a 97 Magna if it makes a difference..

Its a vaccum line. All three connections on that tee fitting should go to a vaccum line, which will have one vaccum source and two accessories that it goes to. It can be emissions equipment, etc. Probably just vibrated loose or popped off when something kicked up. Either way, you need to get it reconnected. You can tell if it goes to the vaccum source by putting you finger over it while running and seeing if there is suction. If there is, you should probably cap it off until you get it connected properly.

I looked all over up and down on the engine, even from under the bike and I couldn't see any place where it should connect. I also didn't feel any suction when it was running..

Looking at a manual from a 94, I'd guess its off the evap control valve. There's a line that goes to the evap canister from the fuel tank. Another line from the evap canister goes to a vaccum line that is tee'd into to evap control valves.

Your best bet is downloading the 94 manual from here if you don't want to go buy a repair manual: Honda / Acura Manuals - Hondahookup.com

Its almost impossible to explain without seeing the diagram. Its really not a big deal to take care of though. The worst it will do is affect fuel economy.

Oooh ooh, this manual is awesome. Thanks for the link, I needed one even if its a few years old. Which page are you looking at? So many pages I'm scrolling through to find "mysterious vacuum hose" :)

Can't remember off hand. The one I looked at was a basic layout, with the engine and carb on the left, and the gas tank in the upper right. Evap canister lower right. Wasn't too far into the manual.

Yea I'm pretty sure its the vapor return hose.. because I've ridden it every day since with no problem. If I sniff the end really hard it smells vaguely of gasoline, but there isn't any liquid gas.

I still have no freakin idea where it hooks up. I was thinking maybe I needed to pull the covers off what I think is the carbuerators, and they only had one bolt, but after pulling the bolt the cover still won't come off. I can't find the T in any diagrams. I was thinking it was the T looking hose on 1-21, but that diagram doesn't seem to correlate with the bike at all..

I have an '84 Honda with some funky hoses too... at a glance it looked like it was just a carb or air box drain hose.. but the T makes it look like otherwise. On my carbs, there are some mysterious vent hoses which hook up to tees. These were very poorly drawn in all images that I could find in my service manual. I basically concluded that they were vents... I forgot exactly what for... but I decided they had a purpose when I was putting everything together... I guess the lesson is- check for connections at the carb(s).