2002 115hp Mercury 2+2 fluctuating rpms on top end

I'm getting very frustrated , I've thrown everything at this motor , carbs and jets cleaned set to factory specs,new fuel pump, new trigger, stator ,regulator , burned and bare wires replaced, and timed ...boat starts and idles, slightly rougher idle than I remember but will run up through rpms until you reach top then the rpms fluctuate between 4700-4100 ,high low, high low, then I bring the boat back to idle and try to run it back up in rpms again it will bog and not plane for a moment, if I bring the boat up to 4000 rpm and just cruise there, boat runs perfect, I've also replaced 2 out of 4 CDM modules , had spark and compression tested, good there... Any help wold be appriciated

Test run with another portable fuel tank and hose.------You do have a water separator in your fuel system ?

When I originally had it in the repair shop , they ran it off a separate tank in order to make sure it wasn’t my fuel lines , no difference

You might try pumping the primer bulb when the fluctuation occurs to determine if it a fuel related problem.