Hi all, I am trying to put my '82 Xz550 back together after a fuel overflow problem. The carbs have been professionally renovated using Keyster kits. Two issues, one minor the other more baffling. There is a long narrow guage pipe coming from the top front of the airbox, where does it go to?? Secondly, the fuel overflow was from the front lower plastic joint which links both float bowls and should have an overflow pipe coming from the same front joint. That joint looks to be damaged so only the link pipe is attached. I don't think this is recent damage so for the last couple of years the 'bike has been running fine without it. The offending joint does not look to be replaceable and is not listed as a part. So, should I ignore the absence of the overflow pipe and carry on or look for a replacement set of carbs (the overflow a few months ago issued onto a hot engine so was quite worrying!).
I think the small diameter vacuum hose you referenced goes to the front carb. There should be a corresponding fitting on the top right-hand side.
That plastic fitting is oft broken by removing the carbs incorrectly through the frame rails. It will run fine but in the event of a carb overflow, will deposit fuel onto the engine. Ordinarily, there would be a small drain hose attached (to the now missing plastic fitting) that would direct the fuel under the bike onto the ground.
If you search this site there are (were?) several members who posted repairs to that carb feature.
Thanks for the information, I'll see what I can find.
The more pressing problem is finding and repairing the cause of the overflow. The only way to find out which (or both) carb is leaking would be to disconnect the overflow connector from one of the carbs and turn the fuel petcock to Pri and observe what happens. V fuel leaks of all sorts are not uncommon and can all be fixed, one way or another.