20kg of drag....dammmmm.....have you ever tried that much drag, it will pull most men off the boat and tired out even the biggest guy....
As previously said get braid, and the key to catching bigger kings is turning there heads, dont let them run to the bottom, pull the run back hard to turn there heads or free spool your line to make the king feel he is either running away the wrong way or free spool till you can get your boat into a better position and away from the reef