Skeeter SX170 Porpoising

[billt23]

I just bought a new 2008 Skeeter SX170 with a Yamaha 90 and am having a bad time with bouncing (porpoising) during the break-in period with the motor trimmed all the way down. The engine is mounted about 2 inches higher than the transom. Is this normal? It's in the 3rd bolt hole. The others on the lot are mounted in the second hole. It kicks up a funny rooster-tail and has a good top-end 45mph but I've only been this fast for about 10 seconds because of the break-in rules. What gives here? We've changed props and it's better but not like it's supposed to be. What should I do next? Do I have any recourse with the dealer? I've had it 8 days.
Thanks.
Billt23


Modified by billt23 at 8:04 PM 8/17/2009

[alexmlane]

I am not all that familiar with that model but on any boat I have ever had porpoising happened when I had it overtrimmed so I have no idea unless maybe you are undertrimmed.

I never run my motor all the way down unless I am trying to plane out. I know you are in the break in period but you should still be able to plane out, trim up and left off the gas to reduce the drag of the boat some and still stay within what the manual says.

Even when I am going under 3500 rps I still trim up and couldnt imagine trying to steer with it all the way down. Trim it up a little bit and see how it does. Someone else might know another trick.

[airc1979]

Do you have the 4 stroke motor??? I guy up here at work bought a sx190 with a 4 stroke 150 on it. His boat dealer had to put some wedge in the motor to stop it from porposing. Maybe thats what you need?