25 hp prop turns but won't push boat past slow

[kd2]

I used my brothers 14' alum. flat bottom boat with a 25 hp Suzuki today. Everything was going fine until the afternoon. Engine started with no problem, went into gear, and went to full throttle with no problems for about 10 minutes (on our way back to dock). Then the boat suddenly slowed down. Engine still ran fine, but boat would only go a little faster than it does with the trolling motor. "When out of the water, I could not turn the prop by hand when it was in reverse, but could turn it when it was in forward. It would also make a "click" sound when turned. Any ideas?

 

[racerone]

Just try another prop !-------May have a " spun hub "--------------The clicking you hear turning in one direction in forward is normal.