tested your code:
Code:
on *:text:*:#: {
  var %unset = 10, %limit = 4

  ; add to a TABLE "flood" the ITEM "<$cid><$chan><$nick><randomnumber> with DATA <dummy-char>
  hadd $+(-mu,%unset) flood $+($cid,$chr(10),$chan,$chr(10),$nick,$chr(10),$rand(1,999)) x

  if ($hfind( flood, $+($cid,$chr(10),$chan,$chr(10),$nick,$chr(10),*) ,0,w) >= %limit) {
    echo $chan $nick wrote $v1 lines on $chan in %unset seconds. limit is $v2
  }
}

to see how it works, and it worked well, how ever shouldn't the flooding use be deleted after he/she have been kicked? cos i noticed 1 small problem, it kicked the same user after 2 lines when he returned to the channel and started to type..

if ($me != tired) { return } | else { echo -a Get a pot of coffee now $+($me,.) }