90 hp mercury 4 stroke intermittently quits pushing the pontoon boat.

[Rick312]

I have a 22' long pontoon boat with. 90 hp mercury 4 stroke. It seems to run great but intermittently it stop powering the boat. Rpm raises a little, it sounds like the prop is coming out of the water. I already installed a new prop and bushing. It only does it above 4K rpm and when we have a few people on the boat. It's like it's spinning out. Do I have something stripped out?

 

[racerone]

Motor is mounted too high.-------------Trim the motor down as a test.----------If so a set of those fins might keep air from getting to the prop.

 

[Rick312]

Although I see your point, I have had this boat for 4 years and it has never done this before. I will try it today though.

 

[racerone]

Boats are funny machines I guess.