OK, you had me worried there, I have had kings almost spool 300 yards, there is a lot of drag on that line and I think it helps them make a big run in the beginning of the fight then does just the opposite and kicks their butt the whole way back to the boat.
2 setups that I recommend -- start with one and then try the other if no success.
#1 - Moonshine Carbon 14 spoon (Best from 200' - 400' of copper)
#2 - White double crush glow spin dr with a no-see-um fly (Best from 400' - 600' of copper)
CC