Rockshox sektor sag

Hi, I've recently bought a specialized pitch comp 2011 model in great nick, it has the rockshox sektor forks fitted as standard. My question is that when I set the sag I have to wind the preload right down to get the 25-30%, I haven't bottomed it out at all and I'm unsure what spring is fitted. Would this indicate I need a softer spring? I'm around 84kg. with out kit.