Finally got things squared away with the Commonwealth of Kentucky. My little 17 foot boat zips up and down the blood river. I do have a question for the performance gurus.

I am not interested in speed per se but I am interested in the way the boat handles. It does fine at 3500 rpm at 25 mph. But at wide open throttle I am getting only 39 mph and the nose wants to fall. And 3500 RPM it rides just as you would desire, but as you add additional power the nose gets lower and lower and the engine cavitates if you try to trim it up to keep the nose up.

Will a jack plate help. I have more than enough thrust to Get up on plane. No problem.

The boat is a 17 foot aluminum lakesport with a 90 hp Mercury. The boat only weighs 690 pounds. I know I need a steel prop.

Your aluminum prop is failing you. When you�re getting up and going the blades flatten out and get the results you see.

Is the motor mounted high on the transom, this could cause your problem? Light rigs are greatly effected by weight placement in the boat, a heavy bow could cause issues like you are explain. Prop makes a HUGE difference, SS prop cupped will help bite the water better reducing blow outs. I am leaning with Pat on this one, prop is probably your problem.

a jack plate will help you keep the bow up, especially when you get a good sst prop designed for bow lift.

i do 6" setbacks all the time on the smaller boats.

i actually just rigged a 14ft havoc with a total of 10" of setback. has a 4" rapid jack and 6" kicker plate behind it.

don't be afraid of running setback on small boats. they run really good when properly setup and the correct prop and tuning is done.