Boat won’t plain starts too then just spins like slipping clutch

[Cracker jacks]

I have a 1989 triumph 5.0 mercruiser with Alpha One out drive The boat starts to plain then you here it start spinning then you won’t go anywhere back of the gas to idle it moves fine any suggestions Thanks

 

[racerone]

Spun prop hub.----Easy to try another prop.

 

[mike_i]

That's what I was going to say. When the boat goes off plane do the rmp's go up?

Spun prop hub.----Easy to try another prop.

 

[Cracker jacks]

That's what I was going to say. When the boat goes off plane do the rmp's go up?

Yes they do

 

[Cracker jacks]

Spun prop hub.----Easy to try another prop.

Thanks for your help

 

[Cracker jacks]

Yes they do

Thanks for your help

 

[rjwilliams11741]

Sounds like cavitation. Are you trimmed properly?

 

[mike_i]

if the rpm's go up and the boat doesn't go faster the prop spun. Cheap repair, let us know what happens.

 

[Cracker jacks]

Sounds like cavitation. Are you trimmed properly?

Yea the same as always before

 

[CR CRUISER]

I had the same symptoms and hoped it was a spun prop. It wasn't the prop, it was the drive coupler slipping on the back of the motor. An ugly thing to replace but got it done. Of course it happened 40 miles from home. Had to come back at 8 MPH.
One tell tale of a spun coupler is smelling burning rubber in the engine compartment.

 

[Cracker jacks]

I had the same symptoms and hoped it was a spun prop. It wasn't the prop, it was the drive coupler slipping on the back of the motor. An ugly thing to replace but got it done. Of course it happened 40 miles from home. Had to come back at 8 MPH.
One tell tale of a spun coupler is smelling burning rubber in the engine compartment.

Thank You for your help

 

[nola mike]

if the rpm's go up and the boat doesn't go faster the prop spun. Cheap repair, let us know what happens.

Or stripped outdrive gears, broken driveshaft in the drive, or spun coupler. Which aren't cheap.

 

[Commander_47]

Try cheap first.....spun prop.

If you have smoke coming from the motor compartment, you may have spun the coupler. The boat will actually limp along for a long time with a spun coupler. But you need to get it fixed pronto. Once it goes....it is gone and you are stuck on the water with no way to fix it. Call for a tow.

I have done this on my mercruiser. I have to pull the motor to fix this on my boat.

Once you get this fixed, make it a habit to check the alignment of the coupler when the rubber seals are replaced on the stern drive.

 

[QBhoy]

Do you have a vented pvs prop on it...with no plugs in the holes ?