Can someone please explain why the fuel overflows into that black tube and into the water on my Mikuni? Is it normal for this to happen when idling around or is there something I can do to prevent it?

prolly need to adjust ur float.... it's real easy, just gotta remove da bowl, pull da float, and bend da tang where da needle attaches to it. Der's a measurement for it but I can't remember, should be able to just bend it a little and should fix it.

Thanks, I know the piece your talking about.

With pictures..