Bob, you bring up a good point. When is the rudder centered? It should be when the control handle is at mid-throw
. This is not always at the 12:00 position so you don't want to set the rudder to the handle visually. When operating your boat, your hand turns the rudder handle the way you want to go -- where it is visually pointing is of no consequence.
With your boat upright on sawhorses, rudder down and locked, swing the rudder full left. Note the deflection angle on the rudder. Then swing your handle full right and again note the deflection angle of the rudder.
Re-center the rudder. If there is any slack, remove the slack on the side that deflected least (the rudder must be centered for this procedure since the lines automatically slack when turning the rudder). That will pull the rudder over slightly and get rid of the slop.
Now go back and cycle the handle again and check for deflection in both directions. If the line was slack, you'll get more deflection now and it should be closer to equal on both sides. If you're lucky you'll be very close to equal deflection and will be done. Otherwise...
Returning to the rudder, now loosen the more acute side and take up that slack on the opposite side. Repeat this process if necessary until you're satisfied with the results.
On your Oasis the handles should be synchronized with each other without any need for alignment.
Now you should find your boat to be much more responsive, with tighter turns and less wandering. With the Oasis and Outfitter, you can further enhance your turns by pointing the rear fins straight down and the front fins up against the hull. This moves the pivot point back and reduces the turn radius.