1976 KZ900LTD

I have had this bike for about a month. I have set timing cleaned carbs. Are these things cold blooded. Have to use choke to start when cold. After it warms up it starts good. Also when running if I put it on kick stand it will stall

It is a carbureted engine, not fuel injection. You must richen the mixture manually when the engine is cold. Your fuel injected bikes and cars do this automatically for you.
If the engine dies when you put it on the sidestand, that is normal, you are changing the fuel levels in the fuel bowls. If the engine dies when you put it on the centerstand, no, that is not normal.

Yes on what he said^^^^

Probably sloshing fuel when putting it on the centerstand and causing it too momentarily flood out.