So I have a 1990 Carver Montego Mercruiser 5.7 Alpha one. Took it out one day everything working fine. Coming into the dock the boat was sticking in gear a little but I thought maybe I had left the throttle engaged. Next day the boat works fine we stop to swim and when we go to head back in the boat won't engage gear. Just reving. Not slipping it just won't engage. After some fiddling it finally went into gear them when we arrived at the dock I had to coast in and have a dock hand help me because it wouldn't reengage. Any ideas? Is this maybe just an adjustment issue? Or something bigger?