Steering Issue

I am currently having a slight steering issue with my bass boat. When turning from straight to left it goes easily, but going from straight to right and back the steering is really hard. It can be used as is, its just kind of a pain in the butt and I would like to know if anyone has any suggestions for fix's It has a rotary style steering system. I have unhooked it from the engine, and the engine swings easily and freely. I have tried greasing the part of the cable that is connected to the engine and everything, it seemed to help a little but not a lot. I have found some different suggestions online such as pumping the cables full of regular car oil, but as im new to dealing with steering systems, I am still a little confused has to what I should do. I am just hoping that I dont have to buy a whole new steering system in order for it to work better.