Here are some tips on centering and obtaining full deflection on your rudder (regardless of rudder size).
Rudder selection and adjustment should be considered part of any performance tuning. Switching to the large ("sailing") rudder is the best single equipment performance upgrade you can make, regardless of your boat or usage. It may occur to some that a smaller rudder has less surface area and therefore less friction.. This may be theoretically true in calm water with straight tracking, but realistically with the Hobie rudder, this is not the case. The large rudder gives better course control with less tending and eliminates constant correcting, especially in more active water. That's where your performance comes from. Add this to more dynamic handling and there is absolutely no comparison, especially with the Adventure (which barely turns without it).
In order to obtain full rudder authority and deflection, the directional control lines should be taut when the rudder is deployed and centered.. All you need is a Phillips head screwdriver to make the adjustments
First, deflect your tiller or rudder control full left and right, and [using a cardboard template or bevel square (shown)] check the deflection angles at the rudder in both directions.
Any slack in the line should be first removed on the side that has the least deflection. Fine tune the lines accordingly to obtain equal rudder deflection from the tiller. Do not make your adjustments based on pushing the rudder back and forth, as this is not how the rudder is operated and will give you a false center.