Challenge: Carb Question

[sbrendtro]

I have two CB750s, a 1975 K and a 1978 F.  I've had both taken apart bolt by bolt (except the engines), and successfully reassembled the K, and almost completely the F.  Here's the challenge... I can't figure out where this carb tube goes:

Part #14 in the following image, coming up off the top side of carb number 2.  I do know that part 3 is the fuel tube, and part 7 is something along the lines of an intake side vacuum equalizing tube.  What on earth is 14 doing?  Its connected through the carbs via 15, 16 and 17.

http://images.cmsnl.com/img/partslists/carb-assy-linkage-cb750f-750-super-sport-78-us_bighu0058e0220_6360.gif

Again, this is a 1978 CB750F, US model.  Any ideas?

Thanks!
Steve

[Re-run]

Hard to tell from the pic but it is a smaller diameter hose right? If so, I think it is just a vent hose.

[shadow06]

that is the float bowls vent tube and line and will connect to a line going to the air box ,emisson controls .or vent to atmosphere if you wish  to .

[shadow06]

that is the float bowls vent tube and line and will connect to a line going to the air box ,emisson controls .or vent to atmosphere if you wish  to .

[shadow06]

that is the float bowls vent tube and line and will connect to a line going to the air box ,emisson controls .or vent to atmosphere if you wish  to .

[shadow06]

that is the float bowls vent tube and line and will connect to a line going to the air box ,emisson controls .or vent to atmosphere if you wish  to .

[Re-run]

Are you sure?

[shadow06]

wonder why it post the answere three times