TOPIC:

I heard a while ago that the kz1000 A1 tend not to be stable at high speeds, is that true? What would be the safe speed for my KZ?

Assuming all bearings, wheels, swingarm, headrace, etc are good and correctly adjusted then if you've any stability issues it'll be due to tires/balance. 
Z1000'S  all had frames made from thicker walled steel tube and don't need steering dampers unlike early 900's and don't suffer from frame flex like they did.

Proviso, the surface your riding on is not full of pot holes! As pointed out by Dr G. 

If you ride your bike hard enough through corners or over pavement that has some ripples or bumps it will shake the bars or worse start going into some form of a wobble. It just depends on how hard you push it. I myself won't ride any motorcycle without a steering damper. I have had some scary high speed wobbles on and off the road race track!! And not just on Kawasaki motorcycles. A steering damper doesn't eliminate wobbles, it just makes them controllable.

 

 

MLMG wrote:

What would be the safe speed for my KZ?

Not moving at all.

Only ride as fast as your skills allow.  Your motorcycle probably knows how to go faster than you do.  I know mine does.  

Scotty

The saying is 
 Don't Ride Faster Than Your Angel Can Fly.
I'm with Dr. Gamma on Steering Dampners
But I have pushed my bike  way past normal limits racing  
 I learned with my 750 H2 what a Death Wooble is............. Not Fun   Had to accelerate  further to  break loose of it 
Tapered steering neck bearings  make a huge difference
All our frames can flex if  pushed to hard.  95 percent of riders don't push to that  threshold 
So , Be carefull and keep your bike  maintained  tight  and enjoy
DD

hugo wrote:

MLMG wrote:

What would be the safe speed for my KZ?

Not moving at all.

Thank you for your feedback.

All the bearings are new, including the roller steering bearings (All Balls).

The motorcycle feels good. Yesterday, while riding on the road at a slightly higher speed of 140 kilometers per hour, I recalled the words that Z1000s tend to not handle well in corners (tend to go straight) and can be unstable.

So, it's better to ask those who know.

To upgrade the cronering performance and high speed stability, i did upgade to a beefier swing arm/wheel combo in the late 90th.

Than:

 

and now five years ago:

 
 
 

MLMG wrote:

Thank you for your feedback.

All the bearings are new, including the roller steering bearings (All Balls).

The motorcycle feels good. Yesterday, while riding on the road at a slightly higher speed of 140 kilometers per hour, I recalled the words that Z1000s tend to not handle well in corners (tend to go straight) and can be unstable.

So, it's better to ask those who know.

There is a big handling difference between my Z1 and my KZ1000.  I don't ride either very fast anymore but have ridden the Z1 at up to 130 mph (on the speedo) without issues.  When cornering you need to look where you want to go, not straight ahead.  Keep your head looking into the turn and pull on your bars instead of trying to lean the bike.  The harder you pull the more it will lean over.  Lastly, don't brake in a corner.  That's a great way to start a wobble.

Each bike is different.
Especially, as the bikes get older.
And depending how much you weigh--Where that weight is placed and how high your forks are in the triple clamps..
That will affect handling as well.
You'll know very quickly the limits of your particular bike when you get to that edge.
There are just too many variables.

hardrockminer wrote:

MLMG wrote:

Thank you for your feedback.

All the bearings are new, including the roller steering bearings (All Balls).

The motorcycle feels good. Yesterday, while riding on the road at a slightly higher speed of 140 kilometers per hour, I recalled the words that Z1000s tend to not handle well in corners (tend to go straight) and can be unstable.

So, it's better to ask those who know.

There is a big handling difference between my Z1 and my KZ1000.  I don't ride either very fast anymore but have ridden the Z1 at up to 130 mph (on the speedo) without issues.  When cornering you need to look where you want to go, not straight ahead.  Keep your head looking into the turn and pull on your bars instead of trying to lean the bike.  The harder you pull the more it will lean over.  Lastly, don't brake in a corner.  That's a great way to start a wobble.

Thank you very much for the information, I don't think I will run more than 100 miles per hour, but later on I will add a steering damper as Dr Gamma suggests.