Jumpy Tach readings - Cable play

I'm wondering if there is a simple solution to an issue I'm having:

My Tach needle jumps up and down when above 3krpms or so. It doesn't sound or feel like the motor is jumping around, and it is riding great. I can wiggle the tach cable as it goes into the engine from left to right, but the connector is definitely screwed on tight. Could it be missing some washer, or some other part missing that allows it to have free play?

The higher the rpms, the more it jumps up and down.

Thanks!

The tach cable inside has square shaft eds that fit into corredponding holes. Even if they canbe wiggled/loose, they tend to not really effect the operation of the tach itself unless one end has come out significantly - which would usually be the cable falling off.

Pull the ends off and check/lube cable properly.

Most likely it is the internals in the tach are getting weak.
You can hook a dremel up to the tach and try different rpms to see if it is the tach or the connection.

Good luck.

The inner cable may have a sharp piece that is hanging up on the outer cable covering, to see if this is the problem, remove the tach cable from the engine and tach, and then pull the inner part from the outer.

While it's apart, clean and inspect the twisted inner steel cable for damage, and lubricate with a light grease & re-assemble. If broken strands are found, only a new tach cable will repair this problem.

My tach does the same thing. My cable is pretty new (couple thousand miles max) and it's been recently lubed.

Engine seems to be running pretty good. Is there anything other than the cable that could cause this? I mean the tachometer itself is 30+ years old.

same issue... i went cafe and i am seriously coinsidering just running a GPS and getting rid of the entire gauge setup, its more annoying than anything, or i have seen a bunch of guys go with the acewell setup, they are electric i believe?

either way i would LOVE to block off the tach hole in the front of my engine, it would stay alot cleaner that way

bearshawk wrote: same issue... i went cafe and i am seriously coinsidering just running a GPS and getting rid of the entire gauge setup, its more annoying than anything, or i have seen a bunch of guys go with the acewell setup, they are electric i believe?

either way i would LOVE to block off the tach hole in the front of my engine, it would stay alot cleaner that way

Offered by Z1E --
Click > www.z1enterprises.com/Tachometer-Drive-B...-Z1-KZ1000-2647.aspx

Good Fortune!

Thanks patton! i remember seeing this but couldnt remember where! once i get the GPS figured out this will be first thing i buy

Yeah would be nice to block off tach output on the head and forget about leaks all together. Even replacing the seals new doesnt last all that long before you start to get another drip on your exhaust.
The acewell stuff and most newer tachs use a probe wire that goes to the ignition coils to determine engine speed.

Hmm... to bad theyre so expensive. really shouldnt be.

Veypor makes a decent unit.

My tach and speedometer both do that too. Tach has gotten a couple new cables and cleaned and lubed several times. Even got another used tachometer to try to stop the issue, better but still there. I actually cracked open the tachometer itself today and the internals don't really have much going on. A little clock spring and a "magnet coupling". Maybe the bearing inside the tach on the drive side could start to bind when it heats up due to loss of lube after 30 years or just play? It the little spring just loses it's... springiness?
It makes me feel better that other people are having the same issue that might just be old meters. I am now more confident that I'm not overlooking something stupid