Has anyone tried to clean out a Cable steering system.  I have hard steering on my boat and need clean the crud out of the system.

If you can figure out a way to do it, you'll be a millionaire....if you're talking about crud inside the cables, it can't be done...there's no way to lube the cable along it's length. Additionally, if it's rusted that much, it's weak. Even if you could get it looser, it's been compromised to the point of not being safe, especially if you run at high speed.

Pull the end out of the motor, mix 50% brake fluid and 50% transmission fluid, hold the motor in up as high as you can with the rod fully extended, slowly let this mixture run into the cable. It's easier if you have two people, after you get some in it work the steering a few time, leaving the rod extended and pour a little more in, do this several times. This will usually loosen them, but as mentioned, depending on how bad the cables rusted inside as to whether you're creating a bigger problem or not. A badly rusted stran can break and jam the cable completely, while driving the boat, not a good experience. Usually better to pay the $130 or so for a new one, double that is dual cable steering.

Oh, by the way, most of the time you have to take the motor off the boat to get the cable out so be sure you use plenty of Marine RTV around the bolts on both sides of the transome.

If you're cables are jamming due to crud (rust) inside, it's time to change the cables.  First, I've rarely heard of anyone succesfully lubing a cable to get it working, at least not for a long and second, why take a chance of your steering seizing or breaking under power due to an internally rusted cable.  Just replace them.  If it's a teleflex system, the cables can be found relatively cheap on the internet (around 90-120 each).  

Thanks, You guys are right.  It will be better in the long run to replace them for 100 bucks.