Buzzing from the headlight

[Finklejag]

I have under 100 miles and the headlight is buzzing. I press down on the top of the headlight and it stops. The buzz is there in 1st, 2nd, and 3rd gear. It goes away in 4th. I guess I can put some foam tape inside to try to stop the plastic on plastic contact. What’s the 8mm bolt under the headlight for, adjustments?

 

[SneakyDingo]

It is called an "adjustment bolt" on the parts diagram. What it looks like is it's there for aiming the headlights up and down. Bolt #5 interacts with the lower portion of #1 in the parts diagram, which is a slotted cutout. This would allow you to angle the entire unit up and down inside the headlight lens, while the headlight lens itself integrates tightly with the housing to prevent water ingress.

I know that people pull this apart slightly to do the USB install on the bike. Best of the Backroads does some disassembly of the headlight to get to the wiring for a USB install if you want to see how it all comes apart with a beer and a click, it's the first part of the video.