9.9 Evinrude Prop Trouble

[RJ]

My late 60's/early 70's 9.9 Evinrude acts like the prop is slipping. Maybe like a clutch is slipping  while operating at higher speed.
It will cruise along fine then suddenly act like the motor came out of the water. Engine revs up but boat slows down.
Does this sound like a bad prop or trouble in the drive train?
Any ideas or experiences? Anybody got a new prop for it?
Thank
RJ

[Bobby Bass]

Sounds like the hub is slipping on the prop. I would pull it off and see if it can be rehub or just look at replacing the prop. Had a twinsport do the same thing and I just replaced the prop. Not 100% sure but that is what it sounds like.

[Lee Borgersen]

Sounds like Bobby's made the correct call. Leave the motor in forward gear and try to spin the prop with the thrust of your hands. This may tell if you need a new prop bushing if it's slipping.

[The General]

I'm guessing this isn't it, but is the motor cavitating?

[Lee Borgersen]

I'm guessing this isn't it, but is the motor cavitating?

If it's cavitating (Ebonics) then DDS is the man you want to see

[RJ]

Thanks for the replies. It started happening very rarely a couple years ago and I thought cavitation also. I experimented by shifting the passenger  to another seat and thought that was it. Then it slowly happened more often until last fall when all I could do was trolling speed.
I'd say you must be right about the slipping prop. I'll try to find another. It doesnt look like it has a replaceable insert.

Thanks again!

[whiteoakbuck]

Sounds like the hub is slipping on the prop. I would pull it off and see if it can be rehub or just look at replacing the prop. Had a twinsport do the same thing and I just replaced the prop. Not 100% sure but that is what it sounds like.

just had to fix mine the other day because it was slipping and that was the problem