Been there, done that
I've replaced mine a couple times.The hint about about calling Edson is a good one, without the instructions it is much more difficult. They faxed them to me when I asked.Both my cables were 8', although I think 10' would be better. Morse and teleflex both make them, as somone said, and West and many other have them. They are somewhere in the $15 to $25 range.The cable comes with a threaded end sticking out the end. The swivel or what ever you call tha piece that goes on the end is not part of the cable. It might be wise to replace them while you are at it. They are also standard parts. I also found them on the shelf at West.One reason the shift cable breaks is that in reverse it bends it against the stering wheel shaft if you push it down too far. There is nothing to stop it from going that far, so eventually you're (or your passenger or most anyone) going to do it. Once it has a bend in it, it is weakened and will flex. Sooner or later, it's toast.Edson sells some sort of gadget that is supposed to stop it from going too far. I don't know what the cost is or how it works - I was too pissed that they'd design it to break, then tried to sell me a fix for their problem. It shouldn't be too hard to make a stop at the transmission end to keep it from over traveling, though. I no longer have the Yanmar transmission (I had to go to a Hurth) so yours will be different than mine is now.Besides getting the drawings from Edson, here is a description of how to do it that may help. 1. Remove the campass and all the items at the top of the pedastal. Take the cotter pins and clevis pins from the ends of the shifter and throttle cable, then remove casting that holds the shifter and throttle handles.2. Remove the wheel lock if you have one. You'll have to remove a cotter pin from the end f the threaded shaft so that it will unscrew all the way out of the break pads.3. Loosen the steering cables so that you can lift up the steering cable chain from the sproket. 4. Move the steering cable chain as far to the front of the boat as you can, you'll need the room to get the cables and their clamp up.5. There is a screw about 5" to 10" down on the back side (toward the rear of the boat) of the pedastal. Mine is a slotted screw, about 1/4" thread. Take it out.6. Now the cables are free inside the pedistal. Move them down, get both cables on the port side of the shaft, then pull them up high enough on that side that you can get the clamp off that holds them together. This is the piece that the screw you took out in 5. went into.7. The clamp is two halves that hold the cable housings captive. Remove the screws and you have two clamp halves, and the cables are free.8. Replace the cable, then put everything back in reverse order.The difficult parts are not dropping any screws or cable clamp parts in places where you can't find them, and getting the screw in 5. started again. Other than that, it's just going through the motions.There is something else you might think of while it's apart. On mine, the salt and corrosion build up on the surfaces where the shifter shaft and the throttle shaft go through the casting that goes on top of the pedastal. While it's apart would be a good time to remove them, clean out holes they go through, clean the shafts and grease it all. They work sooo much nicer when they've just been regreased.Good luck.