carb problem kz750

Sorry for my first post to be a question.I am fixing a 1981 kz750 for my son he gets home in 2 weeks from iraq. The trouble I am having is if the bike sets say over night it will not start on its own.I can spray a little starting fluid and it will start and run fine.And will restart fine if it doesn't sit for a long time. I have cleaned the carbs out put new needle valves in cant replace seats there pressed in.I couldn't get the pilot jets out they are stuck but they seem to be clear.Does any body have an ideal I am stuck

It sounds like the choke enricher circuit in the carb(s) is not working. The "choke" on Mikuni carbs is actually a big jet that dumps extra fuel in when it's cold. If that's plugged, it won't start cold.

As for this:

The trouble I am having is if the bike sets say over night it will not start on its own

Do you turn the fuel tap petcock to OFF when you park it? If not, the carb bowls can overfill and then make the engine VERY hard o start since it's flooded (ask me how I learned that....)

I looked in the manual and it doent give a picture or mention the circuit its a cd I am finding it lacking info.This is is a 750 4 cylinder if you could explain this a little I would be very thankful.
My other son has a kz550 and has a hard time remembering to turn of petcock. I ride a vtx 1800 when he rode the first time he was sitting on it not running.I ask whats wrong he said your always bitching about turning the petcock off so i am trying to find it to turn the fuel on I laughed it doesnt have one.

Would this be a twin or four cylinder KZ750? Kind of makes a difference providing advice.

I put in the other one it a kz750 4 cylinder and h model.Its a 1981 thanks a bunch

Pilot circuit will need to be cleaned and that means removing the pilot jets and cleaning them as well. New pilot jets don't exist for this type carb assembly (CV34).