I have a 60 4 stroke merc ,at wot it seems like it is slipping .

Sounds dumb but that's what it feels like, @ 3/4 it is OK but as soon as I go wot it starts to act up and slip? It stopped my motor today shut it down all together  even kicked the safety switch at the controls .

Anyone know what it could be?

Thanks in advance.

Kevin

You didn't say if this is a new problem, and if the boat has operated well in the past. Assuming it is a new problem, two things come to mind. Cavitation of the prop at speed will feel like slipping as the prop couples to the water and then sucks air. Check the prop as see that is is not dinged on the leading edges, and the bottom of the boat is clean along the keel.

The other thing it could be is a spun prop. The props have a rubber coupling (inside) between the shaft portion and the prop hub. If the rubber is getting marginal it will slip at high power levels, and get progressively worse. You will have to have a prop shop look at it, or just replace it.  :-[

Yes it is a new problem, the motor only has maybe 15 hrs on it.  :'(

The boat and motor were new this spring . There is no dings or anything on the prop.

Work's great at slower speeds, thanks for your help Sneaker.

I will be calling the dealer where we got the boat in the am.

Kevin

Draw a line across the center of the hub, run it, and then check to see if the line is still straight. If it has moved from being straight the hub has spun and needs to be repaired. The issue you describe tends to make me think that is what happened.

Thanks for that Fishfordollars I will try that.

Kevin