mid 80's 9.8 'rude not accelerating

have had this motor on the water about 5 times with 0 problems it pushes my boat great, well yesterday after riding  for atleast an hour around i was pulling out of a very sketchy oyster flat and struck a bar going about 5 miles an hour. no big deal i though the motor wasnt locked in the down position and just popped right up and i drifted and got out with no problems... well half way to the ramp while going about 18 mph it stops moving forward and revs til it sounds like its gonna blow up, luckily i shut it down before any damage was done. fired her back up and limped in at about 12 mph with no problems. Well today i went fishing and to see how she ran, she wouldnt accelerate past 10mph even while the rpm seemed to  continue to rise, when i slowed down the revs she would push forward like nothing happend, what could cause this? my buddy thought it was a loose gear shift linkage that wasnt fully engaging forward, or its was vibrating the lever out of gear at certain rpms, but who knows... any suggestions, motor still runs great but id like to get her back to pushing me around at 25 mph.... sorry for the long post

 

makes sense to me, im gonna tighten the linkage and take her for a quick spin tomorrow morning, if that wasnt it im pretty sure your right about the hub... where do i take it to get fixed, can a marine mechanic fix it for me? how much can i expect to pay thanks alot

 

thanks, got the prop off and it was defiently spun, rubber shavings everywhere, im very relieved that its nothing inside the motor that got hurt. I called that shop twice today but got hung up on once and left a message with no return call the second time... oh well ill just bring it there in person on monday. I did find some brand new props on ebay for $59 plus shipping so i could always to that if necessary. Hopefully ill be back on the water by monday cause the reds have been chewing south of matanzas inlet