I have a 99 champion with a mercury 225 and a manual jack plate this boat is new to me and when I am running on plane the motor will only trim about half way up ,and at idle it will trim all the way up I am looking for possible reasons and how to fix , thanks

I believe that the trim doesn't go all the way up once you are at 2500 rpm or higher. You might check with a mechanic.



I found this on BBC
You have two hydraulic systems in the trim. The trim circuit and the tilt circuit. The trim circuit will allow the trimming of the engine while underway. Once the limit of the trim is reached the tilt circuit takes over and trims the engine all the way up.
If you watch the trim while operating you will see two trim rams pushing the engine, these are for the trim. The large hydraulic cylinder in the center is the tilt ram.
What is happening is the design pressures of the system will prevent you from tilting the engine beyond the trim limit, while underway. This is a safety issue, so it would appear your engine power trim and tilt is working correctly.

k thanks , that sounds right but it don't seem like it is trimming up high enough I wonder if the jack plate is set to low it will only run in the high 50,s the way it is , and wont even throw a rooster tail , I know that don't mean a lot but feel like it should if I wanted to

What pitch prop, rpm @ WOT The prop shaft should be about 3.5 inches below center pad. That a good starting point. Also a 27 or 26 pitch tempest Plus will make that boat fly. You can buy a tempest but it will be the thin blade and doesn't like to be bumped. The tempest plus is a thicker blade and can be tweaked by Steve's prop shop and you might squeeze 80 out of it. Getting the prop B&B will really tune it up.
I have a 27 tempest from MC On my 202