mystery hoses?

[81xsproject]

My bike had no air box on it when I got it. Now I am in the final stages of putting things back together from my winter long resoration project. There are two hose fittings right next to one another that come out of the top of the case. One is a big 1/2" and the other looks like 1/4". Where do these go to?
thaXS guys,
JC

PS What does SWMBO stand for? It's killing me.

[Dragonrider]

The big one is where the crankcase vent attaches . . . not sure on the other one.

SWMBO=She Who Must Be Obeyed.

It's a term from "Rumphold of the Baily" or something like that . . . a British comedy . . caught on and spread for rather obvious reasons . . .

[John]

The smaller nipples, or ports, are for the vent hoses on the 78-79 model carbs to attach to. If these ports are open then the airbox is from a 78-79, if they are blocked off, then it is from an 80-81. Your carbs should only have two hoses leading from them if the carbs are indeed the originals. If they have been swapped for a set of 78-79 carbs, then the carbs will have four hoses. The set of hoses that attach higher on the carb bodies are the vent hoses. If you have that set up, then the hoses must not be plugged. They vent the float bowls.

[Ken Talbot]

The large hose is a crankcase vent that used to go into the airbox. Tuck it away somewhere up under the tank, maybe with a small filter on the end of it to keep out bugs. The smaller hose is a middle drive vent that can just go rearward and point to the ground by the swingarm.

[John]

The small middle drive vent hose actually attaches to a small flat metal bracket that is mounted to the forward mounting point for the airbox, up under the tank.

[81xsproject]

ThanXS boys. one more problem down, infinate unforseen problems to go!
JC

[jazzrat2000]

won't start?

I was reading this, and I think it might be related to a problem I have... I am a newbie to mechanics... today I replaced the valve cover gasket, and was feeling proud of myself until I got it all back together and tried to start it... no go! as far as I know there is only one thing I changed... I put the fuel lines back on the tank, turned the gas on both sides, attached the gas warning light... but I found one of the two tubes that lead to the air filter from the carb area unhooked (the other was connected) and plugged it in like the other side was... could this have made it so gas cannot get to the engine somehow? the bike turns over great, I tried the choke(no help), but I don't want to run the battery down any more until I figure this out...

[John]

The hoses that are attached to the top, front of the air box... are they the hoses that are mounted directly above the carb bowls, or do they attach a little higher on the carbs? The lower set are the fuel lines, and the upper set are the vent hoses which should be attached to the airbox. Did you attach the correct hfule lines to the correct ports on the petcocks?
Here is a link to a diagram of the fuel line plumbling
http://www.xs11.com/forum/showthread...l+line+routing
Just scroll down a few posts, and you'll see it.

[jazzrat2000]

I am going back out to check it out, but I think that the only ones I unhooked were the two on each side that go to the petcocks (and I think I got those back on correctly).. . the ones I am asking about go straight back from the carbs towards the air filter, and aren't long enough to reach the petcocks... when I got the tank up I saw that one of the two was unplugged, so I plugged it back in like I thought the other one was.