TOPIC:

On my kz900 it is installed kz1000 carbs .I can not find any number on them ?

The plugged port on number 3 carb near the cable reel is a vacuum port for a vacuum operated fuel tap.
It must be capped as shown if not in use.
If left open it would cause that cylinder to run very lean.
The ones on carbs 2 and 4 are bowl vents and must be left open to atmosphere.
As long as the carbs are suitably jetted it doesn't really matter what model they came from and being VM26 they are the correct size for all 900 machines except the earlier Z1.
The fuel tee is OEM and depending on model some have a single fuel hose between carbs 2 and 3 and some have two between 1 + 2 and 3 + 4 as yours..

Those are Mikuni VM26's, as supplied on the 1977 & '78 1000A model.  The rubber coated zinc fuel tee's, two of them, are the stock configuration.  From the photo, I can't tell what carb port is sealed, but there are THREE nipples on those carbs; two are float bowl vents, joined with the adjacent carb, and the last is a vacuum port, on the #3 carb.  

Thank you guys then im able to order some parts when rebuild them. They leak a little not sure where but it was gunky fuel at the bowls.They was rebuildt by a kawasaki dealer in 2019.
I suspect the fuel tees are leaking so will have to separate them and put in new orings

Those fuel tee's don't use O-rings.  You can order after market Tee's that do, though.  I prefer that type.

I have O-ring kits for those carbs, if you can't find a full set otherwise....

From the first pic you posted, I pulled it down to my laptop and enlarged it.  I can see a partial ID stamped below the choke level.  However it is not clear enough to read it. Things I will say about the carbs you have they do have 2 fuel inlets, a vacuum port on #3 which is plugged as Zed indicated and they do not appear to have an air screw.
I have attached a pic of the location of ID stamps on the carbs.  Note the pic I have attached is of a different set of carbs than yours but the location should be the same.

Thanks gd4now  i zoomed in with my phone and found the marking. yes they dont have a air screw ,but they have the mixture fuel screw in front underside of bowls 

Nessism wrote:

Those fuel tee's don't use O-rings.  You can order after market Tee's that do, though.  I prefer that type.

I have O-ring kits for those carbs, if you can't find a full set otherwise....

Thanks for info Nessism i think i read in another tread that you have nitril rubber orings i will contact you later when i find out what i need