SeaPro 199 bow porpoising

[Planecrazy]

Last year we bought a 199 with the hard tee top and love the boat but I feel like we are losing a ton of performance from the Suzuki 175 because we have to run the trim tabs once the boat is over 30mph. The motor is mounted on the transom in the second hole, which looks to be the correct mount height. I run the boat with the motor trimmed all the way down. Soon as I get about 30 I have to start deploying the trim tabs to keep the bow from porpoising. At wot I am pushing right at 6000rpm with the Suzuki Watergrip 15x21R propeller. I am not sure exactly which direction to go. A 4 blade will give me stern lift but rob the motors performance. Transom wedges would allow for more negative trim. I would like to hear what other have done.

[gnrphil]

Is the out board mounted in the second hole from the top or the bottom?.
Have you tried trimming the motor up some when on plane to see what happens ?

[Juan]

What phil asked...

I'd first check motor height... The motor mounted too low will cause a boat to porpoise so be sure your anti cavitation plate is skimming along on top of the water when the boat is on plane. If it's under the surface, raise the motor a notch.
Second, I'd move some weight around. Too much weight toward the stern could cause the problem. You might move some gear or even batteries toward the bow.
Lastly, You can experiment with props. A four blade or a deeper pitch could help.
Is it possible the previous owner mounted the hard top too far to stern?

[Planecrazy]

The motor is mounted on the second hole from the top. I have played with the trim. Trimming it up while porpoising makes it much worse as you would probably guess. I bought the boat new so the previous owner would have been the factory and they mounted the t-top. This is a new model for them. They have said the it may just be the nature of the hull.

[Juan]

Sorry, my bad. I misread your post as a 1999 Sea Pro so assumed there was a previous owner. From the pics, and mounting location it looks like you know what you're doing and are on the right track. I'd move some weight toward the bow and then experiment with props if that didn't help.
Btw: Welcome to the forum.

[985crabs]

My boat used to porpoise terribly.

I put a hydrofoil on the lower unit. Problem solved.