Hi guys,

I was looking into why my fuel sensor idiot lights don't work properly (only the right light comes on, and even when there's more than 12l of fuel in the tank).

And I've just discovered that my motometer circuit doesn't match my manual...

The manual says I should have 4 wires from the tank to the instrument cluster, but the cluster doesn't support 4 wires (pin 8 is missing, and the fuel sensor board is only a 3 pin in, 1 pin out). I have a thermister-based sender in the tank, and pin 8 is present on the plug that connects to the back of the cluster.

Should I be concerned? I guess if the cluster is not original to the bike, I can't trust the kilometres on the odometer either? 

Can anyone tell me what year the cluster does apply to, based on the photo?



Thanks,
Kev

Many of our Ks have had instrument swaps over the years. The change came in mid 1985 with the early bikes having 2 lights and later 1 light. All the other things will work in the instruments, bar the fuel light. I have a post 85 set of gauges from a K75 on my 83 K100. Just zero your tripmeter and use it to work out fuel usage.

The thermister sensors are known to be inaccurate and sporadic.  I have one in my 85 and it has the same problem.  I don't know what can be done besides living with it, as I don't believe you can even get a new thermister sensor.

Sounds like you've got a later instrument cluster on an early setup. Inge can probably give you the changeover dates from thermistor to variable resistor; the good news is that if you can find a cheap early instrument cluster with a busted speedometer, the tacho (rev counter) is easy to change over. The type of cluster you should have has an amber 7l warning and a red 3l warning light in the tacho (left) side. The giveaway is that the two lights in the tacho both have a petrol pump symbol next to them. You don't show it, but I bet yours only has the pump symbol next to the rightside light.

I've probably just seriously confused Inge because IIRC, to him the tacho is the speedo!

Yes, you can trust the distance reading. If UK bikes have a mileometer, do European bikes have a kilometer?

I just checked my 85 cluster (which I am certain is correct for the bike, it has older style pins, and missing the two 'gortex' like breather panels) and it does not have the 8th pin from the top on either of the two plugs.

All the motometer gauges for the K100/K75 will give accurate readings for mph and distance. Well as accurate as they ever were.

Thanks for the replies...

Two clarifications: By "I can't trust the odometer", I meant that I can't trust that the distance shown corresponds to the distance travelled by the bike, as I have no idea when the cluster was changed.
The bike could have 300k on it...

And yes, my cluster has the goretex breather holes and only 1 pump symbol next to the right-hand warning light (with no markings on the lamps themselves).

Side note: since I didn't have the karamba software, I've been manually tweaking the speedo varistor to get the displayed speed to match the GPS speed (it initially under-read by about 20%). It should be pretty close now.

Dai wrote:I've probably just seriously confused Inge because IIRC, to him the tacho is the speedo!

Yes, you can trust the distance reading. If UK bikes have a mileometer, do European bikes have a kilometer?

Me too! At first pass I thought you meant the rev counter! Or you are saying that to Inge the rev counter is called the "speedo"?

I use the generic term "odometer" so as not to involve the unit.. but yup, my odometer measure kilometres. Well, I hope it does, since the speedo measures in km/h!

It seems that in many European countries, what we (the UK) refer to as the 'speedometer' is known as the 'tachometer' and there is a different name completely for the rev counter.

As other allready have said.....in the picture in the first post is of a PCB
for the float level sensor which was used on later models than yours.

About speedo/tacho.........AFAIK it's only in das Vaterland the speedometer
is called a tachometer.......and the tachometer is called a drehzahlmesser.