We've been banging on about the wisdom of finally replacing your boat's old and worn chain and wire, and offering a spoonful of sugar to help the process along. The response has been very encouraging, and as TravelLift operators across the country hear "ladies and gentlemen, start your engines!" it's time for a quick tip that will help get the new season off to a great start.
With the chain and wire disconnected, and the top of the pedestal exposed, manually move your rudder to as close to centered and straight as you can get it by eye. Most boats have enough space between the top of the rudder and the hull to wedge a small wood block between the two to hold the rudder in place. From there, go on deck and put that turkshead braid or loop of tape on the wheel's rim at 12 o'clock and tighten the wheel brake. Next, fold the chain in half to find the center link, and place that center link on the sprocket so that equal lengths of chain fall on either side of the sprocket.
As surely as the salmon return to Capistrano, at least one boat in every other marina will suddenly steer "the wrong way" after launch. This is because steering cables that should be crossed haven't been, or cables that shouldn't be crossed have been. Edson idlers are easy to ID as being made either for crossed wires or not, per the pics below.
Since I constantly need to simplify things as much as humanly possible, I've come up with an easy way to see whether cables should be crossed or not. If the cables go around the rudder post, the cables cross. If the cables don't wrap the rudder post, don't cross the wires. getting this right ensures that when you turn the wheel to the right, the boat agrees and heads that way. A bad thing to mess up.
When you go below to lead the cables to the radial/quadrant, make the connections with the cable clamps (orienting the clamps correctly!) as evenly as you can. This is more art than science, but try to get the cables close to "snug" with as close to the same tension on each side as possible. From there, using a box wrench that's specific to the size of your cable clamp nuts (doing it with an adjustable wrench or pliers is a pain in the butt), take 3 turns on the right cable and then 3 turns on the left and so on and so on until the cables are the right tension.
Having done all this, the reference mark on your wheel will point directly up when the wheel is centered, you will have full steering range in both directions, and your boat will turn in the direction you want it to.