DON:

I HAVE A '96, 200 HP MARINER OUTBOARD ON MY CHAMPION BASS BOAT. THE MOTOR GOES INTO GEAR EASILY BUT AS SOON AS YOU GIVE IT GAS, THE ENGINE MAKES A LOUD THUNK SOUND LIKE SOME GEARS ARE NOT MESHING CORRECTLY. THE LAST FEW TIME I USED THE BOAT, IT WOULD MAKE THE SOUND ONCE AND THEN RUN FINE. YESTERDAY, THE SOUND WOULD CONTINUE IF YOU RAN AT ANYTHING OVER IDLE AND WOULD GET LOUDER AN HARDER SOUNDING IF YOU TRIED TO GIVE IT ANY GAS. ANY IDEA WHAT THIS COULD BE?

YOUR HELP AND ADVICE WOULD BE GREATLY APPRECIATED.