Jetting help again please

[t-balls400ex]

I have a 1999 400ex with e-series pipe and two 2 inch holes in airbox currently running a 170 main jet. I know this is too big when it gets hot it will start to flutter on top end.I want to change main but dont know to what also needle clip position.I ride in mo. right now it is 90 degrees and humid if that makes a difference. Please help

[yellow_ho_01]

i run a e-series slip on,.. welds ground out on head pipe,.. no choke,.. no airbox lid,... 2 pre-wares( one on the filter and one custom made to cover the whole box) a White Bros foam filter,.. about 10 discs on the exhaust...with a 165 main jet,... i think im at like 2 1/2 or 3 1/2 turns out on the mixture screw.... and my ex runs great!!!! dont know if it might help seeing what everyone else runs,.. here its been in the 90's with lots of humidity....