Jetting Help

[brad_400ex]

I put in a jet kit with my modds in my sign. i put a 170 main and put in the new needle and put the clip in the 3 position and turned the fuel mixture screw out 3.5 turns., I also have a K&N and no airbox. when i let off the gas it backfires quite a bit and it doesn't like to idle and the spark plug is white like i am running lean, do u now what adjustments i should make. my elevation is 1230.
Thanks for any help

[brad_400ex]

anyone?

[Kilabanshee]

I think i ran a 165 jet in my 400ex with my yoshimura pipe but iam not quite sure.