carburetter problem

i have a 1981 kz750 and am having some problems. when i got the bike it would idle at about 4 thousand rpms. we opened te carbs up and found that all the floats etc where clean but we did find the black cylinders at the top of 3 and 4 where hanging up a bit. we cleand them and the seemed to be movoing freeley. if these where hanging up again would this cause the bike to idle high and sometimes die?...also the bike has aftermarket intake (4 little cone filters) and also custom 4 into 1 exhaust. could those be causeing any problems with the idle? thanks.

could be carbs,idle adj,vacuam leak,ignition adv hanging up
oh wait,cv carbs! paging dr von otto! :laugh:

would buying new bigger jets help?...since i am running pods and the custom 4-1 exhaust?