Bog at WOT

I have an 05 LTZ 400. Its my wife's bike and back up bike for buddies so it does not get ridden every time. The last few times I took it out it has had some carb issues. Started with bad idle, I could adjust the idle and get it to idle but rpm seemed a little high. All in all it worked through out the day but didn't want to run great unless you were on it. Took it home, pulled the bowl and cleaned the jets. Fast forward a month later. Took it out riding again and seemed to idle a bit better but would really bog and sputter when you rolled on the throttle (anything above half throttle). SO I took it home and it sat another month or so.

Over the weekend I changed the oil & filter, replaced and oiled air filter with a new uni, new spark plug, drained old fuel and replaced (petcock seems to be flowing freely) and I tore the carb out. I took it all the way apart (air/fuel mixture screw also), cleaned every orifice and all jets everything had a visible clear passage. I ran carb cleaner through the passages of the carb and blew it out with air (120 psi max my little guy will do). Put it all back together and the idle is fixed, it starts and idles great. I can whop on the throttle in neutral and it seems to build up the RPM's just fine. But when I ride it, same issue, if I stab the throttle it just bogs out and wants to die. I assume it is either a float issue (bowl is running dry) or plugged main. I am thinking maybe I need to get a carb rebuild kit and go from there as it is over 10 years old now.

Just looking for some opinions or suggestions. I am wondering if maybe the timing is off, bad valve, or CDI/coil is going bad? Some suggestions of things I am not thinking might be helpful. Thank you in advance for your help.

This place is like listening to crickets??? Is there anybody out there??? Any suggestions or input would be helpful. Thank you in advance.

have you removed the box lid ? whats the jetting ?