99 fe400 electrical or fuel?

I originally posted this in the general forum, but I think this is a better place to look for help with this. I also tried to explain a little better what is happening. Does any of this sound familiar or typical?
I'm wondering if I should also post this in the fuel forum, as I'm not sure if it’s electrical or fuel?
Hoping someone can assist with this. I have a 99 fe400 with super low hrs. It ran fine 6 mos. ago, but now I have a problem with high speed running. It starts fine- choke on 2 kicks, choke off - 1 or 2 kicks and it starts right up on idle. Throttle response is great thru 1st , 2nd, 3rd gear, at the top of 4th is seems to hold back a little and when I shift 5th it starts to sputter and jerk quite a bit at low to mid throttle, its pretty erratic, if I give it full wick throttle it dies like there is no fuel or spark(stalls), when I let off it kicks back in. 6th gear is also erratic , even more so than 5th it also seems to stall with full throttle as it tries briefly to go, blubbering and lurching. With the throttle completely off in 6th it stalls as well, give it a little and it comes back. I’ve had the carb off/apart and cleaned and blew out everything I could find & changed out the fuel, I thought for sure I would find a clog in the main as I’ve had this before with my other bikes. Also changed the plug, pulled off the stator cover too see it looks like new, tried adjusting the carb air screw (which didn’t seem to help just made it harder to start). Is it possible an electrical component is failing? Am I missing something in the carb a passage or something? I bought, this bike used with only about 75mi on it and it ran great, I haven't ridden it much because the stock suspension didn’t suit me, I just had it all done by enduro expert in NJ, put some short bar risers on it with a softer seat, I thought I was ready to ride but now I need to iron this thing out.
I would really appreciate any help/ ideas you guys have.
Thanks - Bill

Thanks for the response,
I will check that, if I can get the spec. The only thing is, the float looked perfect no cracks , leaks or even discoloration, the carb was clean as a whistle, like new. This problem i'm having began before I took the thing apart, and continues exactly as it was before I cleaned the carb, if its the float height it would have to had changed on its own, between rides, it did sit for a little while but was started pretty regularly. Can the float height go out of adj this way? If someone can give me the spec , I will check it, to be sure its good.
Thanks again - - Bill