Rotten transom? & check valves or stoppers for deck drain

[phatdaddy]

sounds like you need to raise the motor & stand on the foot and bounce to see if you have any flex. if not, then maybe you can get by with patching the drain, if you do, search transom rebuilds. i also have an 83 and the only bilge pump i have forward is in the deck box and it goes overboard in the stern, easy to get to. maybe yours was added by a po. where is the thru hull located.