My 1986 2.5 liter OMC Cobra (Rinker boat) has decided to stop letting me raise & lower the prop. When I push the switch, it clicks back there, but nothing else. The problem began out of the blue--it wouldn?t go down; however I ran the boat for a bit in the raised position; then it agreed to go down. However, when I tried to put it up again, it went up a little, then stopped. That?s all she wrote. Any clue what the problem is likely to be? Thanks...