There has been discussion in these forums about the steering and available adjustments. It should not be stiff. The tight lines will make it stiff though. There is an adjustment knob under the steering handle (I suppose you saw that?) turned one way or the other from (Loose when centered) will add tension to the lines. You should start with the knob at the loosest setting and tension from there.
There is a possibility the lines were crossed when the tube was assembled to the drum Check routing.http://www.hobiecat.com/community/viewtopic.php?f=26&t=13071