Carb Question..........

[Pennies Earned]

So my carbs are in perfect sync and the bike runs great. I happened to see a used carb for sale as I was browsing other stuff and noticed something. There are three hoses on the inside of the carbs, all three of which are connected to the inside nipples of the other carb. Well the photo of the used carb shows the uppermost inner line not connected to the other carb but ran down the carb, not plugged into anything, and held by a metal ring of sorts. Hope this makes sense. Do I need to unplug the top one and run seperate hoses? bike is a xs650b

 

[5twins]

Yes, unplug that top hose and run separate hoses. Those are vents for the float chamber and should vent to atmosphere, not be interconnected carb to carb.

 

[Pennies Earned]

Thanks 5twins. I haven't run them long connected together but would there have been any consequences of running them like that?

 

[5twins]

I'm not sure but it's possible a vacuum may have developed in the bowls causing fuel flow to slow or stop. Kinda like what happens if your gas cap vent gets plugged.