81kz650csr speedometer and tachometer not working

I am a long time viewer and occasional poster on this site as i have been fixing up my 81 kz650csr. Long story short about my current problem. When I bought the bike both the speedometer and tachometer worked well. The bike developed a bad engine tick and sat inside for about 12 months, I finally fixed the problem (faulty cam chain tensioner, lucky me!). Now neither gauge works. They are both connected and the cables seem fine. I bought a Clymer guide but it doesn't have the info i need. From I research I have found that the problem is usually tied to the cables but i doubt this is my problem since they stopped working together. the indicator lights work in the gauges, could there be some kind of fuse or wiring issue causing my non-function or are both gauges strictly mechanical with no electrical component?

any input will be greatly appreciated

-Bewildered

On the KZ650, the stock speedometer and tachometer are each driven by their own, separate cable, and each meter operates independently form the other. There is nothing at all electronic about them, and they do not connect to a fuse. They do have instrument lights in them, and the lights are on a fuse with other stuff, but that cannot affect the operation of the meters, only the night time meter visibility.

I suggest you check the cable for each gauge. The cables simply unscrew at the bottom of the gauges and at the cylinder head for the tachometer and at the speedometer sending unit at the left side of the front axle for the speedometer. You can slip the inner cable for each out of the sheath, clean it, and lubricate it lightly with motor oil. That may solve the problem. Ed

If you disconnected the gauge set to work on the engine rattle perhaps the cables aren't seated correctly at one or both ends. As 650ed says, they are totally mechanical (apart from the illumination lights) but it is weird they've stopped working at the same time.

I'd disconnect the cables at the clock end, start the bike and see if the tacho cable turns.
If not I'd further investigate the cable itself and the drive.
Then lift the front wheel off the ground and spin it as if you were running forwards to see if its cable spins.
If both cables spin ok I'd check they seat fully in the clocks.

You can check the clocks themselves using a battery drill/screwdriver and an old broken allen key or similar that's the right size to go in the clock.

Good luck, keep us posted.

I thought they were both mechanical, that is what baffled me. I found the issue for the tachometer. the cable had snapped about half way up, an easy fix and from what i've read, a common problem. As for the speedometer, perhaps I did something when I removed the front wheel to replace the fork seals. I have checked with my other 81kz650 and i appear to have installed everything correctly, i'll do some further investigating.

Glad you're making progress.

I had a similar problem with the speedo on my '81 Honda xl250 when I took the front wheel off to have a new tire fitted.
There's a tab (tang maybe) on the wheel that fits into the drive on the fork. It was very slightly bent so that while everything looked ok the wheel and speedo drive didn't engage properly. Took me ages to suss out what was wrong. Might be worth a look to check yours on the kz.