Tach bouncing above 5k rpm

[SNott]

Strange, it didn't use to do this. Now when the rpm's are over about 5k the tach just bounces around between 5-6k and doesn't read properly. below 5k seems fine. does it in all gears.

Any ideas?

Thanks....

[DanTheMan]

Your tach cable is getting ready to part company with the driver down at the engine. Probably needs lubing as well. If you catch it soon enough you can save it. You'll find the the slotted driver on the cable unscrews and starts that bouncy business. Clean it well, mix up some high temp jb weld, put it into the driver hole, screw it back together. wait for it to dry, lube the cable, re-install and you should be good. Also, make sure your cable connections top and bottom are tight, I lost a cable on the road when my bottom one unscrewed.

[tkent02]

You have an electronic tach with no cable?
Not sure why but my '83 750 did it too.

[SNott]

Electric tach.... maybe some corrosion = bad signal, guess I can try tracing the wire and cleanign up any junctions

[tkent02]

I remember a thread somewhere on another bike forum about repairing this tach problem, I never did the repair, don't remember which forum it was. It is a common problem and a fix is out there somewhere. Good luck.