I have been fixing up an old sea sprite tri hull with a 55hp Chrysler on it. I am very new to working on outboards. I had to rebuild the carb and get a new starter in it and finally got it up and running. Every was working good so I brought it out to the lake. When I got there I put the boat in the water put it in reverse and nothing happened. I then put it in forward and nothing happened again. I know the cable isn’t stuck because I am able to shift it. It seems the be something on the outboard is stuck. What could this be and how could I fix it.