some set-in is built into the suspensions, if you are trying to eliminate the set-in, sag, or trying to get the suspension to return all the way to the top, you will have to put ALOT stiffer springs to accomplish this.
in doing so you will have a very very harsh ride.
suspension tuning is a trade off, there are two schools of thought in tuning for sled/rider compliance.
1: stiff springs and softer shock packages
2: soft springs and stiffer shock packages.
you will need to find a happy medium for YOUR riding style. ski