Outdrive slipping out at high rpms please please help me

i have a 25' 1989 2556 bay

i have a 25' 1989 2556 bayliner i bought used took it out today first time ran pretty good all day dont know if right but i cruised at top 3000 rpms kinda hard or stift shiftn all day on the way in rpms jumped up high and sound like omc outdrive was slipping down throttled drive pick back up and kept spinnig i eased it in to the marina foreward and reverse seemed to in gauge fine with a little stiftness does this model have that clutch Dog thing what can i check or do it felt like and sound like a clutch in a car slipping thanks in advance for any help

I think You might have two mai

I think You might have two main problems:
Your shift cable engine - drive seems to be due for changing (hard/stiff shifting)
Your propeller sounds like it is slipping in the hub. Re-hub or change prop.