Carb Hook Up

[550ERAT]

Ok, hopefully I can explain this......83 GS550E with the Mikuni 2 barrel carbs. Carbs have been fully disassembled and cleaned. They are back on the bike and I am about to do a sync. (carbs were put on last season-bike ran (rough), but ran)....Anyway. I was looking at them today and noticd there are two extra nipples for a hose connection, but none are there. When sitting on the bike, the right carb has the fuel line connected to it just above the fuel connecting rod. The right carb also has a vacuum line attached to it and goes to the petcock. Both carbs have this extra nipple (approx 5/16 like fuel line size) They are closer to the front of the carbs (engine side). My manual shows them with a fuel line going to them but that can't be right. So what am I missing? Are they like pcv hoses? vents? Should they be connected to something? The bike is running rich ( I think) and want to make sure everything is where it needs to be before I try synching. Thanks. If more info is needed, let me know.

[BassCliff]

Hi Mr. 550ERAT,

I think they are vent hoses. On my bike they just lay over the airbox and hang down on the back side away from turbulent air thusly:




I think this should be true for your bike too. Let's see if one of the other "double-barrel" 550 guys shows up to verify.

Thank you for your indulgence,

BassCliff

[550ERAT]

I'm hopin thats all they are. They are not needed to sync the carbs, right?

[skreemer]

there should be two vents that face each other on the "inside" between the carbs...

then the fuel and vacuum lines..

the ports to do the vacuum test is a slot head screw on the outside... and there's only one per "carb pod"...

on my 550 I don't have the vent lines attached and the bike runs just fine... but I do find that under very heavy breaking (emergency stops and screwing around) that a little bit of gas will come out the vent holes and splash the top of my crankcase. Not enough to cause a problem and it evaporates almost immediately. (though I have a "T" line made up to cover the vents)

[550ERAT]

Thanks. only one car has a vac line tothe tank as far as I can see. Is that right?

[skreemer]

yup... 1 vac 1 fuel and 2 vents.