What is this headlight adjustment?

[Bigalone]

I have a 1993 ST1000, and the headlight has a strange adjustment screw mechanism on the back. Check out the photo. Turning the vertical screw rotates the circular wheel on the headlight back. I can't figure out what it does.

Any ideas?

 

[David Fyffe]

Does it raise and lower the aim point of the headlight?

 

[Bigalone]

It does not seem to do anything!

Does it raise and lower the aim point of the headlight?

It does not seem to do anything!

 

[PmodelinUS]

I have a 93 also. I have not opened up the faring yet but given the location It probably attaches to the headlight adjustment knob on the left side of the dash. Mine was really aimed poorly. It took several turns to get it to start moving the headlight.

 

[STRider]

The knob on the dash adjusts the vertical alignment of the headlight. Something you'd do to compensate for load.

That screw adjusts horizontal (left-right) alignment. Something you shouldn't ever need to adjust... Unless you're poor @Lucida

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[jfheath]

In the UK, incorrect horizontal alignment of the headlights can be an MOT failure - as oncoming traffic can be dazzled on dipped beam.

 

[ST1100Y]

In the UK, incorrect horizontal alignment of the headlights can be an MOT failure - as oncoming traffic can be dazzled on dipped beam.

And they're fully correct to pull them off the road on the spot!
Hate all the glare produced by ignorant drivers (and riders!) with wrongly adjusted and/or wrongly equipped headlights...