Wants to be lean?

[Supernovabjt]

Just picked up an 03 ec300, and I'm having a tough time getting it to run right.
The guy I got it from had it jetted 170 main, 40 pilot, and an unmarked needle with a #6 slide.
It would run well at low rpm/throttle but would fall flat on its face if you went past about 1/3 throttle.
I read up on here and ordered a N3EG needle, and put in a 175 main and #7 slide as that seems to be a successful combo. Not the case for me.
The only way I can get it to run halfway decent is to put in a 160 main with the needle on the highest clip. Spark plug is a dry light-medium gray.
It also has a hanging idle issue, that will eventually come down, to a very low idle with the idle screw turned almost all the way in. The idle mixture screw does almost nothing.
I know very little about the history of the bike, seems to have quite a few hours on it based on the wear on the frame. A new top end was put on before I got it.
Fuel is pump 91 with amsoil saber at 100:1. Sea level, 75 degrees.
Anybody have any ideas what is going on?