A cam plate too far forward can keep the cam from fully locking. A cam plate too far aft will allow the rudder to slip aft in the lower casting or allow the upper casting to be raised without pulling the cam open. To adjust the upper plate, lock the rudder down and hold the rudder firmly against the lower casting (forward most position). Loosen the upper plate then back it away from the cam a little. You want to seat the plate tight against the cam (in the fully locked position) while holding the rudder forward in the lower casting. Ease the plate forward while wiggling the upper arm up and down just a bit. The idea is to find the point of deepest insert that the upper plate can get into the cam. That may mean that the upper casting is not touching the lower casting. Don't force the plate too far forward as this will begin to force the cam open. When tightening the plate, be sure the plate doesn't move. I usually tighten with the wrench handle rotating forward towards the cam to move the plate forward if anything.

RUDDER ALIGNMENT -

Check rudder alignment in the direction of travel. Proper rudder alignment would be 1/8" to 1/4" toe-in on a 14 or 16. This is measured with the rudders down. Measure leading edge to leading edge and then trailing edge to trailing edge. The front (toe) should be closer together than the trailing edge. Measure at about the little hump on the leading edge and straight back from there for the trailing edge. It is always possible that the rudders are actually mounted on the reverse hulls. That causes extreme toe-in problems. Look at the upper casting / arms to be sure they angle in towards the boat's centerline when the rudders are in alignment with the hulls.