Fuel Tube to #2 Cylinder Help?

Hi Guys,
Just got a 1981 XJ650 Maxim and I'm going through the usual routine restoration and maintenance. The bike was barely running, and when I did get it going it died after riding for a block or so. Also, the exhaust coming from the right exhaust pipe made an intermittent sound in comparison to the steady sound resonating from the left side. I decided to clean the carbs, and when I removed them, realized that the fuel hose coming off the top petcock exit was disconnected from the #2 cylinder rubber carb holder. Once removed and inspected the carbs were relatively clean, and so was the in-line fuel filter. Any ideas if the hose disconnection was the cause of my bad idling and running to begin with? Also what is the purpose of having that tube to begin with? Thanks in advance for your time.
-Remy

 

The tube needs to be hooked-up to any one of the Intake Ports. Engine Vacuum to that tube opens the Vacuum Operated Petcock Valve.

If the Tube was not on ... the performance would be affected because AIR would be introduced to the Intake and cause the Mixture to be Lean.

With NO Vacuum to it ... the Petcock should have closed and the Engine starved for fuel.

 

That's a vacuum tube that opens your petcock, if it's disconnected at the boot, then that would be an air leak that could affect idling, but also it would mean that there'd be no vacuum to open the petcock.

 

Hook it back up. You'll be happy!