first time jetting. help?

I have a '00 kdx220 and I bought my bike used so i dont know what jets it has but the jetting seemed to be pretty close last summer.

i just got my bike back from getting it ported for more mid and i added boyesen dual stage reeds. and the problem is.. when i go past 1/2 throttle the bike would continue to rev but not pull anymore, but since i was still breaking in the new piston i thought it would fix it once the rings seated. now the bike is broken in and it still pulls real hard down low but it still flattens out after 1/2.

so what am i looking at in jetting changes? i have absolutly no expirience with jetting so i might need alot of help.

i also have a fmf kg-30 and silencer, i ran my bike at 20:1 for break in, and now im at 40:1 (both are with natural oil) and both ratios do it. last year i ran my bike at 50:1 with synthetic.

if u need any other info just ask. thanks alot.

thanks kev rm. that could be true, i havent cleaned it yet. when i was putting the bike together after the rebuild i was gonna try to clean it but i decided to wait till i got a service manual. now that i look at it, it looks like i'm goin to have to tear the bike down again to get at the KIPS valve.

but since it was ported for more mid and its flatening out at mid throttle thats why im thinking its jetting. am i way off on my guess? any other opinions.