The XB12R headlights have been loose since I got the bike. It hasn’t been that noticeable during the day, but at night it looks like I have a headlight modulator.
I took the fairing off and had a look. I had thought maybe just the four screws that hold each projector headlight on had worked themselves loose, but not so; the reason the headlights were loose is because the adjuster screws themselves were loose, allowing the lights to move back and forth with engine vibration.
Two of the adjuster screws for each light are somewhat easy to get to, but there is a third (which I guess wasn’t intended to be an adjustment screw) that is impossible to get to without removing the entire support frame.
I printed out the Buell service manual, which explains how to set up a test bay for proper headlight aiming: draw a line 36″ above the floor on a wall, then park the motorcycle with its front axle 25 horizontal feet from that same line. The low beam should project a rectangular box of light with a sharp cutoff at that 36″ line, and the high beam should project a circular area of light centered on that same line.
Well, I had a lot of trouble both properly aiming the lights and getting them to not be loose. What I ended up doing was completely undoing the high beam’s adjuster screws and placing five or six washer shims between the light and the support frame. That enabled me to tighten the adjustment screws to the point where the high beam was both properly aimed and securely fastened.
Now the XB12R’s headlights are set up the way they should be, which will be good both for notifying people I’m passing them and for use at night.
The 1125R’s service manual says you can use the same test bay setup for it, so I’ll do it next. I’m not sure about the Ninja; I’ll need to look that up.