Boat porpoises at wot

I have an excel 2172 with a Yamaha 150lb. Boat porpoises above 4100 rpms, if I put 100lbs of weight in the bow, it runs fine. I am looking for a permanent solution. Raise or lower engine? Change prop? Any help is appreciated.

what the prop set at. You need to try and set it at 3.5 below pad.

The dealer set it at the bottom of the pad, I'll try lowering it. Manual jackplate.

Porpoising on a bass hull usually is caused by the prop losing its grip at the current trim angle.

You didn’t say what prop you’re running so that would help.

If it’s a decent wheel than usually lowering a bit will cure the bounces.

After that it starts getting a little more detailed.