Tacho on 1981 z650 f2 doesn't work

I need to hook up a tacho from z650 f2 to a cam which is from z750. Can this be done, and what do I need to make it work and read the revs again?

Any suggestions?

if both cable tachos then easy, if elecronic then you need an ignition +ve and pulse wire -ve (usually thin black wire) off one of the coil's -ve.

cable to electronic= easy

electronic to cable = not easy, unless you replace the tacho for electronic inside the guage -also the redline and rpm sweep might be different.

Dont know this? From original first owner I got the story that it is because the "pinion gear" on the original camshaft has broken and because he couldn’t find the original cam for z650 he bought and installed it from z750. Apparently this however doesn’t have the gear (or it is different, didn't quite understand) so the cable can not be connected thus the rev counter doesn’t work.
The question is what should I do to make this original tacho work again? Finding an original z650 cam and replacing the one it has and works well, seams like a big task just for making the tacho work.
Any suggestions?

You'll either need to swap the camshaft or get an electronic tachometer.
Probably the best fit will be an elec tach from an 80s model that is similar in size/shape.

In the USA here are some models with round meters & electronic tachometer,:

82 KZ750 GPz, 750N Spectre (shaft drive) & 750F Ltd shaft.
KZ1000-J, 1000-K Ltd and KZ1000-P police (82-2005). possibly a few 80s KZ1000/1100 shaft drive models.
The redline is probably different on all of them & you'd need to verify the physical fitment of a non-stock meter.

Easiest would be a stock cam or one with the drive from a 750. I'm planning on getting a electronic tach for the parts to put in my old housing. As stated above, they have to have the same red line and size. It's complicated but I no longer have confidence in aftermarket ones.
Steve

It means if I want to keep original tacho need to go back to original cam with all bits and pieces including postage, could cost at least 150 Euro, looking roughly on what I could find on ebay. Pitty to get rid of original tacho cause it is in great shape, and the loss of original looking bike not to mention. Thanks for advice anyway.

I'll be doing the conversion soon and start a thread on it. Don't you have a Euro eBay over there? You could save a lot buying in your own market.
Steve

If possible, I would try to find out what Z750 camshaft was installed & ask if they swapped the intake cam.
Also, I would remove the valve cover to verify whether or not it has the provision for the mechanical tach drive.
And I would remove the tachometer pinion stuff to see if there's any damage there or something. doing this might be opening a can of worms, though. there is no telling what's been done. previous owners can be the worst.

I'd take off the cam cover to confirm what you have been told. Previous owners have been known to, um, "exaggerate." :whistle:

I foun out the cams are from Gpz750, so need to fin out which clock is the closes looking and based on magnetic system, or replace the cams with kz750e or h which are for mechanical geard system and keep the nice original tacho. Decisions, dec :whistle: isions!

What cylinder block & pistons are installed on the bike? It might not be a 650 any more.