How do i tune the carburetor? z750-82

My carbuerotor needs to be reconditioned. The motorcycle has not been used for a couple of years, and I think that only 2 cylinders are running

Soo. Take everything apart is no problem, and clean it up and everything.

What I would like som help/informatino about is how to adjust the carburetor after I put it together again.

As I see it, I have 3 things that I have to adjust.
1. Fuel
2. Sync between cylinders
3. Idle speed.

If there is enything else, please let me know!

So. my questions:
1: I know that the service manual says how to set this needle. how many turns from "all-in". But I dont have the service book. (I found one on the internet, but it wasn't for my bike )
How many turns from all in should I set the needle?

2: I bought 4 vacuum meters. And I saw on a video on youtube that you remove a screw in the aluminium pipe between the cylinder head and the carburetor. but. i cant find that screw.
Where do I measure the vacuum on my bike?

3:This is just a screw mounted facing the cylinder head right?

Thanks!

Looked at the attached picture... if the needle that the arrow is pointing

to it is the one you are talking about... OEM (STOCK)setting is two (2) complete turns from seat.

Hope that helps.