Power issue

[chazaroo]

Had the boat out yesterday and couldn't get it over 24 knots and that was at 4000rpm. Anybody got a clue what's going on.

 

[Turtlesboat]

did you check the bottom and drives for growth? that'll slow a boat down in a big way.

 

[Theresamarie11]

Is this all of a sudden (yesterday it was fine and today it's not) or has the boat been sitting for some time and now it's performance is bad?
What speed would you normally get at 4000 RPM? And what are you measuring speed with? If it's the speedometer, check that the pitot hole is open and not clogged in the front of the drive. Check the simplest things first.

 

[chazaroo]

Boat has been sitting for a about three months. Speed was measured with GPS. Top speed usually high thirties.