Spun prop hub.......... take it to a prop shop or get a new prop.

-W

wrote in message
oups.com...
I have a 1970 20 HP Mercury. The engine is running fine, but the last
time we had it out something seemed to break between the engine and the
prop. The prop will turn when the engine is running slow, but when
trying to run faster the engine revs and the prop won't turn any
faster. (Like a clutch is slipping.)
Any suggestions? .............. Thanks, John...