Can you ID this knob?

[Cohiba54]

It's between the low beam and the right high beam as you sit on the bike. Discovered it while replacing low beam light.

[lkraus]

It's the headlight angle adjuster.

[Cohiba54]

 Kind of thought that’s what it was Lkraus. Can anyone confirm that?

[lkraus]

Editing as you replied - pics from the Repair DVD.

[Cohiba54]

Thank you Lkraus. I presume it’s the vertical adjustment and clockwise is up. Is that correct?

[wbw6cos]

You may be able to see the headlight assembly move as you turn it.  On my 19" RT, there is a 2 or 3" paddle (lever) that is connected to that type of knob which moves it to adjust for 2 up, etc.  I cannot recall which direction, though.  Sorry.  I do remember that you can see it adust the reflector as you rotate it,  Good luck.

[Green RT]

Is there some reason why:

It is knurled to turn it by hand

It has a hex nut for a wrench or socket

It has an Allen head for an Allen head wrench

Do the three turn different things? Maybe the hex nut/allen nut is separate from the knurled knob, but why both a hex and allen fitting.

[Selden]

29 minutes ago, Green RT said:

Is there some reason why:

It is knurled to turn it by hand

It has a hex nut for a wrench or socket

It has an Allen head for an Allen head wrench

Do the three turn different things? Maybe the hex nut/allen nut is separate from the knurled knob, but why both a hex and allen fitting.

 

Why not? Arguably over-designed, as BMW is wont to do, but if the knob is too difficult to turn by hand, you have the option to use either a socket or a hex wrench, whichever is available. Note that the lateral adjustment knob on the right is similarly redundant, as it also accepts a phillips-head screwdriver.

 

To find out which way is "up" :

1. Place the bike on center stand, in a location where the headlight is pointed to a smooth vertical surface, such as a garage door or wall.
2. With some white paint, mark the starting position (or photograph it).
3. With the headlight on, turn the adjusting knob 1 full turn; you should see a noticeable difference in where it's pointing.
4. Return the knob to its original position, and fine tune from there, if you that the aim needs adjustment.
5. For future reference, on a piece of tape draw an arrow to indicate which way is up or down, and tape it somewhere near the knob.

UP

When syncing the throttle bodies on my RT, I could never remember which way to turn the adjuster on the right one to move the balance left or right, so I put such a piece of tape on the back of the fuel tank.