89 750 idles high or way to low

[repo10851a]

its a 750, stock exhaust 4-2, the carbs are jetted to what looks like stock.
The bike idles ok at start but once it gets warmed up it idles at 3k and if I fiddle with the idle adjust, it will get to low and bike will idle at 800rpm and eventually die and it hesitates when you give it gas until rpms are back up. Or if you adjust idle back up it goes back to 3k. There is no middle...
here is what i've done so far :
wiring to coils is good ,
plugs are ok,
plug wires are good,
valves are within specs,
checked ohm readings on coils
cleaned carbs very clean, diaphrams are good. I did notice clip on needle was at the very top position. making needle at lowest position.
used aux. tank to test, nothing changed.
removed air box to see the slides they lift and return equally

I've owned bikes with cv carbs, and I thought they ran like crap without airbox? Maybe it was only when they have a load e.i if I was to try and ride it like that (but I forgot to try it on this bike). This bike runs the same without airbox (in neutral at least)

I couldn't find an air leaks,
floats are adjusted , pilot screws are at 2 turns out, ive tried 3, 2.5, 4,
I've found 2 was the best, but still does same idle crap.

Any idea's
I have worked on lots of bikes in my time but this one has me lost.

[DumbLuck]

given your needles have adjustment grooves they're not stock. you prolly have a jet kit in there. now the question becomes who's, and stage one or stage 3. somewhere on here there is a thread with pics of each kit mfgr's needles for you to match. i went thru absolute fits with a dynojet kit as teh owner told me it was stage one when it was actually stage 3 with the air jet drilled out. a/f screws needed to be set to 4.5 turns out. about the only way to tell if the air jets are drilled is to take them out and measure them up against stock.