Many times the cause of K bike
speedometer flakiness is poor connections inside of the
instrument cluster. This is especially true for 88 and
earlier model years. Here's how to correct the problem:
1) Remove the instrument cluster
from the bike. Exact mounting varies by model but all of
them have four 5mm Allen bolts in recessed holes in the back
of the instrument cluster. (Info on how to remove the
instrument cluster from various different models can be
found here.)The wiring harness connector is
secured to the back of the instrument cluster either by a
Phillips screw or 3mm Allen bolt.
2) Place the instrument cluster
face down on a towel on a table. Remove the nine (seven on
85 and earlier K100s) Phillips screws from the perimeter of
the back of the instrument cluster to remove the instrument
cluster's back plate.
3) Once the back plate is removed
you will see a three terminal connector on the top middle of
the back of the speedometer. It has three long pins on it.
That's usually the culprit. Pull it straight up. A small
screwdriver can be useful to pry it out.
The picture below shows the
inside back of a later cluster that had small screws to hold
the connector in but this is the general location of the
three pin connector.
4) Clean corrosion of of those
pins with some steel wool, fine sand paper, whatever. Then,
before reinserting it into the back of the speedometer,
twist each of the pins slightly. That will help to ensure
that they maintain good contact when they are reinserted.
5) Put everything back together
and go for a test ride to see if that fixed the problem.
© 2013 Drake Smith - Please do
not use or reproduce this elsewhere. Feel free to link
to it though.