White and frame ground is stupid - who turns off an engine by a controlled short?
Just do this, if you haven't already:
Get rid of the yellow button kill switch - buy a $2.00 switch as seen in pic, dremil a space for it in the throttle handle, and make it a kill switch that connects/splices to each side of the BLUE wire. The yellow switch used w/ the white wire is notorious for creating a short which will eventually fry the magneto. = $30.00 + shipping to replace.
Now you have a real kill switch that you can control easily when riding. I like to let my bike idle for a moment before shutting it off. And this makes it very easy to do so.
I got my switch at Autozone for $2.00.