I was driving in the other day on my boat and suddenly it revved really high and i had to crawl into dock - as accelerating would raise the revs but no movement. I assumed i had spun a hub. the next day i removed the propeller (a little bit of crap did fall out) and checked it and it appeared to be fine so i tightened it back on, tried the boat and everything seemed to be fine.
any ideas
any ideas