ok i had this bike running very poorly on 1 cylinder the other day.....it seem though as if i wasnt getting fuel to the other cylinder because that particular cylinder wasnt getting hot at all like the other...i did notice a fuel leak when i filled up my tank. so i decided to take the carbs off and make sure they werent dirty and when i took them off gas started to run out of this fitting between the carbs that is pictured below.
I would think that i am just missing the hose that supplies the other carb with fuel but there is nothing pictured in my manual where these fittings are located
please give me some advise...btw 1 jet was clogged that i cleaned out but i really would like to know if i should put a hose between these two fittings before i put them back on the bike
not sure if I can give you any definitive advice on this, as I am almost as stumped as you. given that those fittings don't seem to be in evidence on the carburetor breakdown from your manual, I can only figure that they are one of two things:
1. fuel crossover fittings (possible, but not likely - my old suzuki, which had 4 carbs, had a solid metal crossover tube)
2. carburetor vent fittings - this is the more likely possibility. on a new bike, there would be a rubber hose attached to each of these fittings and routed down out the bottom of the bike.
The carburetors have these vent tubes to allow excess fuel vapors to vent out and also to allow the interior of the carb to maintain normal atmospheric pressure and avoid vapor lock.
not having a tube there isn't a major problem, it just means that any excess fuel that might overflow out the carbs (from a faulty petcock/float valve) will vent onto the top of the engine case instead of out the bottom of the bike onto the ground.
I'm gonna guess those are overflow tube outlets or vent tube outlets. It looks like in the second pic, those metal tubes running over the pens your holding are fuel crossovers......?
A leaking float valve could be allowing one or both carbs to overflow and pizz fuel out of those vents.
BTW.... not to be a jerk or nothing .... but those carbs don't look all that clean.
You should have a set of lines coming off of them that routs the over flow of fuel down under the bike.
As far as this being the cause for no fuel to that cylinder it's highly unlikely.
It sounds as though the carbs will need a good cleaning.
If you checked your plugs and the one not firing is dry then the jets must be clogged in that carb.
You might want to inspect the slide diaphragms at the same time for cracks and tears as this will cause problems with fuel flow as well as carb synchronization.
Once the carbs are cleaned and reinstalled remember to balance them with a synchronizer.
If you don't have one they are really easy to build just do a search on this forum for directions on building one.
They are vents, but do not require a tube. I believe they are just for vapour.
The float bowl overflows are on the bottom of the float bowls and should have a hose routing them to the ground, away from the engine and rear tire.
While you have the carbs apart it's a good idea to inspect the float bowl overflow tube. It is common for them to have a crack and leak fuel at any level.
I am tearing down my CM400E And Need a Manual cant seem to find one but right now I am stuck at getting the carbs off I have the tank, seat, side panels, and most other parts off cant get the carbs off the air cleaner box doesnt seem to have a way out with the carbs in place. I have a little experence with mechanics and Know that taking the carbs off a gold wing can be done by just twisting, and a little brute force. is this the way you have to take these out? I keep looking and thinking but could use some help
tia
ride free and always remember Drive like Hell you'll get there!
.... but those carbs don't look all that clean. 
