The K75RT, K100RT, K100LT,
K100RS, K1, K1100RS and K1100LT all have the same headlight
assembly. It is unique to K bikes and not used on any other
vehicles. It mainly consists of a reflector and lens:
All K bikes use a standard
H4 (a.k.a. 9003) dual
beam headlight bulb easily obtained online or at an auto
parts store. (I use LED H4 headlight bulbs in my Ks these
Looking from behind, this is how
it is wired:
Changing The Bulb:
When dealing with H4 headlight bulbs be very
careful not to touch the bulb glass with your fingers. If
you do then the natural oil on your fingers sticks to the
glass. When the bulb gets hot (and they do get very hot)
this oil will heat up and can cause the bulb's glass to
break. If you do accidentally touch the glass then clean the
bulb off with something like rubbing alcohol before
This first things to do are to 1)
pull back the rubber boot and 2) wiggle the connector to
remove it from the back of the H4 bulb.
BULB RETAINERS - There are
two mechanisms used to hold the bulb in place. Early K bikes
have a "locking ring" and later K bikes use something that I
call a "squeezable spring."
- The locking ring needs to be rotated counter-clockwise in
order to remove the bulb. Once rotated about 40 degrees the
ring will come free and allow the bulb to be removed.
Installation is the reverse of
If you lose the locking ring or
are missing it for some reason the BMW part number to
replace it is 63121459470.
- Push in and squeeze as shown below. The spring can then
rotate over to the left to release the bulb.
Adjusting Beam Direction:
LEFT/RIGHT - Turn the knob
clockwise to adjust the beam towards the left or
counter-clockwise to adjust the beam towards the right.
UP/DOWN - There are two
mechanisms for adjusting beam height: a white lever for
macro adjustments and a black hex knob for fine tuning.
The white macro lever has three
positions: up, middle and down. This is handy for quick
headlight adjustments when you have changing loads. e.g.
Riding solo with no luggage vs. riding 2-up with full
luggage. Up is the highest pointing beam and down is
Turning the black knob clockwise
lowers the beam and turning it counter-clockwise raises it.
© 2021 Drake Smith - Please do
not use or reproduce this elsewhere. Feel free to link
to it though.