03 04 kx plug fouling

anyone else out there who is also having problems with their 2003-2004, all they do is foul plugs. i have had mine rejetted 5 times,mixing good oil (silkolen pro sx) at 32:1 also tried 40:1, tried runing iridium plugs hot, cold u name it. all it does is just chews through plugs and it is getin worse and worse. it starts off as if it is running with the choke on then it will sneeze and crap on and then die, as soon as u put a new plug in it will go fine again. once it was doing it i tried pulling the choke on the see wat diff it would make and it made none so i put it down (off) and it cleared itself, yet other times it doesnt always do this. any ideas? all bike mechs have looked at it and they dont have a clue cos it goes when they put a plug in it so they send it home but it keeps happening. why?

162 main, 52 pilot. 1st clip pos on stock eedle. plug chops have been done and looks to be jetted correctly

yes the 250 comes with a Keihin PWK38S with power jet