Convert mechanical tachometer to electric?

Greetings,

I've swapped GPZ750 head/cams onto my KZ, and as a result lost the ability to drive my mechanical tach.

I understand that there is at least one related Kawasaki model, the KZ750 Spectre, that used an electric tach of the same form-factor.  The easiest option of course is to source one from a bike breaker, however my existing gauges are in nice shape and the Spectre gauges I've found so far are not in the greatest of shape.

So, I'm wondering if there is any possibility of swapping the "guts" of an electric tach into my mechanical unit?
Or, are there other electric options I should consider?  I prefer the classic "twin gauge" factory look over some of the later (i.e. GPZ) or aftermarket options that I'm aware of.

TIA for any wisdom imparted.
 

I don't have an answer for you, but I've been researching the same topic. So I'll be hoping someone chimes in with some info. 

I've never heard of anyone swapping the guts. First thing I'd do is measure the meter to see if they're the same size as the Spectre or KZ1000P police or whatever other models had the electronic tachometer.

I have some 1000P measurements that someone provided:  the meters are 92mm diameter measured across the face and the mounting studs are 73mm center-to-center. There are other measurements, but these two are probably the simplest and will probably tell you straight away whether or not the guts from another speedo will have a chance of working. 
My 650-CSR meters are larger (100mm face diameter and 84mm stud c-to-c). my meters are the same size as several other models, but none have an electronic tachometer.

ps: the 750 Spectre meters might be larger than mine. 

What about attaching the gear to the camshaft? Either mechanically or welding it on with silicon bronze? It’s pretty lightly loaded 

Stinkfinger,
Years ago I bought the guts of an electric tachometer to use on my KZ750. What I bought came from a Kawasaki and not the model I had, but I was going to try and adapt it to my bike. Let me look for it, I can't even guarantee I still have it.  Looking at the wiring diagram from the 750 I owned (1983 KZ750 F1 Shaft) which had an electric tach, shows the wiring is ground, power, and a third wire that splices into the black wire of one coil. If I have it, you are welcome to it. If you can somehow mount this electric unit in the mechanical tach and get the needle shaft to line up with your faceplate, and figure out the wiring part, why wouldn't it work?  Also you can find the wiring diagram for the F1 in this website to see how it hooks up. 

 I'll get back to you.
Kent

converted mine z650 by using internals from a suzuki gsx750f, based on an idea by 'injected'
hardest part was trying to remove z650 needle broke the spindle

another option
Tacho Electronic- Z-series (z-power.co.uk)

I have been using that same electronic tach from Z Power for 4 years now with no issues. Played with the idea of running the Spectre gauges but could not find a set in decent shape, so buying the electo tach was the easiest/cheapest option.



My KZ650 runs a 1982 KZ750 Spectre engine (no tach drive gear) I run it off a negative coil terminal on my Dyna green coils Dyna S ignition.