The 2002 and earlier Marzocchi forks have a rebound damping cartridge in one fork leg and a compression cartridge in the other.  As has been pointed out by GuzziMoto, if you remove the spring from the compression side and cycle the fork leg up & down you will feel a point where the damping suddenly increases alot.  This is due to some oil bypass holes in the side of the cartridge being blocked by the damping rod piston part way through its stroke.  If you look at the attached pic you can see