We have a 1997 Malibu Sunsetter, new to us last season. At planing speed, the rudder is unresponsive through many degrees of steering wheel input, maybe 45 degrees estimated. At displacement speeds this is not true.
The rudder appears straight and undamaged, no signs of contact with anything, same is true of the tracking fins, all three look straight and undamaged.
The propeller is a new Acme 515, installed by me, alignment checked good, no vibrations.
The steering cable is new, installed by me.
There is no play in the steering system, I had my ski partner hold the rudder firmly in place while I tried to turn the wheel, solid, with zero play.
There is no play in the rudder port.
I'm stumped, need some ideas.