I had this problem with mine when I first got it. The most effective fix is to completely replace the Rudder cams by drilling out the rivets holding them, pulling the ball and spring out and cleaning them thoroughly and then replacing everything. if the cams are in good shape then you can keep them but if they are cracked at all or severely worn then I recommend getting some new ones. ... However if you don't want to go to all this trouble the quick fix is a simple flat head screw driver. Insert it between the ball and the cam and press the ball down so you can rotate the cam into the Rudders down position. this has always worked for me when my cams over rotated or were just plain stuck. but usually if it happens once it will happen again so it is best to do some preventive maintenance and just bite the bullet and do it.. if you have the right tools then taking apart both cam systems and cleaning them should only take about an hour.