Speedo and Tach issues have me stumped

Kawasaki Z1A.

I just git finished with a gauge and cluster rebuild. I took the whole mess apart, never touched the internals at all. Replaced all the bulbs, cleaned the glass, replaced the lower covers, repainted the upper covers, replaced the cover with the idiot lights, replaced the bracket that holds the things together, and all the rubber dampers etc. Put the stuff back on the bike and went for a test ride. The tach and speedo needles bobbed around and for sure were not reading accurately. I checked for looseness and both were not completely snug at the gauges, or at the lower attachment points. Snugged them also. Another ride showed some improvement but still had some wavering needles, and inaccurate readings. I am at my wits end and it is hot out in that shed. In the am I intend to detach both at both points, remove the cables and check for any fraying. Am I missing something?

If the gauges are incorrectly tightened to the support bracket they will be stressed internally and give poor readings. Make sure they aren't over tightened or tweaked in some way. Make sure all of the spacers and rubber washers and the rubber material on the bracket itself are there and in good shape.

The entire bracket and all the dampers and foam are brand new. The only difference is that the original dampers have a metal collar (see part #3) that limits the degree to which you can tighten the nuts holding the gauges to the bracket, and the new ones do not have this. I did speak to Chris at Z1 Enterprises who advised me to get them "just snug". I think I did so, but I guess in addition to inspecting the cables I will be pulling the whole mess off again. Chris also told me that if you just buy the dampers they are just like the originals and have the collars or posts inside the dampers.

Yep, item 3 allows you to tighten the nuts enough to prevent the meters from vibrating loose while still allowing the meters to float on the rubber cushions.
Someday, when I've spent all the money I can on this bike of mine, I'm going to go with electric reproduction meters.
Yah, right...

Make sure your cables are correctly routed and properly lubed as cables not right can make needles bob as well.

All fixed, thanks guys. I did pull both cables and inspected them. They were as good as new, so they were cleaned, greased with moly graphite bearing grease and reinstalled.

I took the gauges apart again and gave the bushings some thought. Again, they are not the factory type with metal inserts. After examining every conceivable way to mount the gauges with what I had at hand, I decided to secure the bushings prior to installing the gauges in the bracket because they kept squirming about. I used a dab of super glue to get them oriented right (small end toward the gauge). This made getting the gauges on the bracket more difficult, but it can be done. I then noticed that one of the relieved areas (the ones needed to clear the rubber bulb holders) was way off spec. The older bikes have an extra bulb in the tach for a stop light indicator. The bracket was contacting this about 1/3 or so. This did not allow proper seating. Instead of grinding the bracket, I used a scalpel to cut the foam as needed, and to slice a portion of the bulb holder away allowing the gauge to seat on the foam. I used some clear rtv silicone to touch up the bulb holder where I cut into it. I then installed the flat washers, opted not to use the lock washers, and after a dab of blue Locktite, ran down the nut until it made contact and added about 1/3 to 1/2 a turn. Many wiggle tests showed this to be very solid. I then ran down a second nut on Locktite to hold the stuff together better than just a split washer.

I then went out to my Japanese POW torture box of a garage (metal octagon with not AC and 104 flippin degrees in the shade) and put the stuff back on. A test ride showed all is steady and right with the world. The speedo is rock solid, the tach had a hint of a bobble but I may be over sensitive to such right now. It is so minor I will leave it be.

Nicely done Jhenry Glad you got it working and thank-you for the informative post on how you fixed the problem!

My own workspace isn't much better than your boiler room but it keeps me and the bikes out of the elements