There are only two hose connections on the airbox. One is 1/2" inside diameter and located on the top forward face of the airbox. It goes to the breather on the valve cover. The other is 1/4" diameter, and may have a 90 deg bend to fit onto the airbox fitting which is located on the bottom center of the airbox or on the lower rear face.
If the hose is 1/4", it is not a float bowl ventt tube. Those are 3/16" Fuel is 5/16" Only vacuum hoses are 1/4" line. It may be the hose for the carb#1 to carb #4 vacuum balance. Frequently, carb #2 does not have an external vacuum nipple. #2 balances internally with #1. Vacuum from #1 is "jumped" via external nipple on #1 to carb #4. #3 draws internally from #4. The nipple on #3 operates the vacuum petcock.
(there are/can be other vacuum tube arrangements on different GS models)
Earl
If the hose is 1/4", it is not a float bowl ventt tube. Those are 3/16" Fuel is 5/16" Only vacuum hoses are 1/4" line. It may be the hose for the carb#1 to carb #4 vacuum balance. Frequently, carb #2 does not have an external vacuum nipple. #2 balances internally with #1. Vacuum from #1 is "jumped" via external nipple on #1 to carb #4. #3 draws internally from #4. The nipple on #3 operates the vacuum petcock.
(there are/can be other vacuum tube arrangements on different GS models)
Earl
bradleymaynar said:@#$^%#@!!!!! :x Well, it is NOT the tube from the airbox. That one is like a half inch in diameter, while the other one is probably around 1/4". I got the airbox off and there is only one tube hooked up there. I'm not sure what this other one is for at all!! I can't find any other hook ups on either the airbox or the filter box. It seems to have oil around the top of it. I know it's not from the tank because all those lines came off with the tank. (Which, coincidentally, I found that an in line fuel filter had been put on the "prime" line!) I don't think it's from the carbs because I don't see any hook ups there! It seems this isn't so simple!
Brad tt