79 KZ1000 ST E1 speedo and tach are loose

Can someone tell me how to tighten the speedo/tach or if there is a bushing that gets dried out.

if it has seperate tach and speedo like the earlier bikes pull your headlight bucket to get access to the 2 nuts under top triple tree that hold the mounting bracket.
if the gauges themselves are shaking but bracket is tight pull the phillips screw off the bottem of each gauge bucket and check the nuts on mounting studs.
theres also foam pads between gauges and mounts

Most Kawasaki instruments are rubber mounted, perhaps your's have dried out/cracked. Remove the cover for the speedometer and tach(it's usually a couple of screws for each) and lower the covers. The cables might have to be removed for better access, so now you can re-lube the cables.

www.z1enterprises.com should be able to get you new rubber mounts. I use a silicone spray to keep mine from cracking(apply it with a cotton swab before installation in your case).

I clean my speedometer cable with some paint thinner & rag,maybe every year of so.

A light grease is about all you'll need, but check for signs of the twisted wire cable coming apart as the wire strands can make the instruments erratic in operation.

Quick fix is to take apart, the 2 studs from the gauges were the 8mm nuts are. Pull the collars out and cut them down a 1/3rd or so and re-bolt.
To do it right you need the new foam pieces on the gauge bracket and new rubber grommets over the 2 studs.

My tack is looser than the speedo and my rubbers are fine. How loose are you talking? They have to be somewhat loose to negate vibration from damaging them.

that might be what I'm feeling/talking about.