[K100]

I've got an 87 bmw k bike i'm building. I don't want to use original gauges, nor have any to use, instead i want a single tacho mounted on my triple tree, a la a classic cafe.

The stock tachometer system gets it's read from a signal coming from the alternator, and juice from (of course) a 12v electrical circuit.

What can i use to replace the stock tach?

Is it OK to use the tach from a smaller engine, ie, 2 cylinders? If not, can anyone recommend a similar four cylinder bike with an alternator-fed tach?

Thanks!

 

[shift1313]

Im not really sure about that. I just looked at this wiring diagram and it looks to me that it has a line to one of the coils.

http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/k100 wiring diagram.jpg

Do you have a wiring diagram that says otherwise? You can see the Blue line goes into the gauges and turns to green for 12v+, Brown is earth ground and black is signal

 

[Jackstand Johnny]

I think it'd benefit you the most to ask something like that on a forum specific for your bike. maybe someones already swapped tachs on a bike just like yours. I dont wanna steer you from here, thats just what I'd do.