force 120 hp loss of power

[southenjim]

hello, im new to this site and i was wondering if anyone could help me out with a problem with my 1987 force 120hp outboard engine with is on my bayliner capri boat, first off the engine ran very well getting about 35knots after having a great time on the water with it, anyway last week we put it in the water and took it out and found that the engine was not running as it should, at full throttle i was only getting 3000 revs and the speed was well down, i have the engine manual, also when i put it in reverse i seem to get a grinding sound? with no motion at all? im hoping someone could point me in the right direction to where to start looking.