Tuned engine idles poor

[zxrplendermen]

Hello,

This winter i've ported the head on my zxr. after rebuilding the engine i cleaned the carbs in a ultrason bath.
after all the small things i decided to give it a try, and YESS, it runs.

when the engine was warm i synchronised the carbs. the result was a better running overall.
it spins up verry quickly, and it is much faster then before [i've made a test drive].

oke, now to the point: it wont idle! now it runs @ about 2.5K
if i turn the idle screw down, the rpm's drop to 1K for a second and than dies.

anyone?

Greets Jan