need help finding out where this tube goes

I have no clue where this tube goes searched all over and cant see where it ties into any help would be greatly appreciated.

 

Always helps to state which bike and which yeaR, but that vaccum line goes to the petcock in order to flow fuel from tank into carbs....unless the petcock has been modified, but in any case the line must not be open to atmosphere.

 

Thanks! Its off an 1985 vfr500 interceptor. ill mkae sure to do that next time if post. That is what i originally thought as well but the petcock must be off another bike because there isnt a place for it.