I know it's mainly trial and error. I don't think there's any danger in moving the jack plate up and down the full range while running fast. But for trim, how do you know when you're trimming up too much? I'm sure it becomes obvious at some point, but how do you know when you've trimmed as far as safely possible? I have a Ranger Z20 with a Yamaha 225. I can only get it to about 50mph by GPS. My boat guy (who is well-respected and trusted her on TFF) cleaned the engine, changed filters, separator, good compression, etc and said he got it up around 64mph. Thoughts?

Watch your gps. Just slowly keep adding a little trim until you start loosing speed.

Thanks for the quick response. This is my first fiberglass bass boat. In rougher water, do you guys tend to not trim up as much? Seems like maintaining control could become an issue but I haven't experimented with that yet.

Yep, mostly keep it trimmed down in rough water. Take your time and you will get a feel for what works best in your rig. Seat time will teach you. Sometimes when it's rough but not to big I trim it high and skip across the tops of the waves for a smoother ride.

Watching the water pressure. Problem with trimming it up in rough water (3-4fters) is that every 5th or 6th wave is wider and will drop the bow into the wave and then your wet all over.

actually it is NOT a good idea to be running your plate up or down at W.O.T. unless you use SMALL BUMPS
UP!!! going up to fast could blow the prop out and you won't like those results.

set your prop shaft height at around 3" below pad.. while sitting on a flat surface. then at w.o.t.
use the small bumps to see how it effects the running of the boat. once you find the optimal setting. mark
the gauge, that way you'll know where to run it at.
as far as trim... use it all!!

I would listen to Steve. Trim limiter went out on my Laser once and I was doing a dance on the transom when the prop lost bite. Not fun for a few seconds. If I had been headed in to the wind I would have flipped.

Thanks for the info guys. I think I just wasn't trimming it up enough. I have a Bob's Jack Plate on my 2007 Ranger Z20. I trimmed it up further than before and got over 60mph today. Kinda scary actually.

I'm confused on not moving the Jack Plate while driving. I have had other people recommend starting out of the hole shot with the JP up high and then move it down right away as I come onto the pad. And trim up.

you can do that. you just don't wanna be moving it very much at w.o.t. especially going UP

Thanks again guys. I was back on Eagle Mountain this afternoon and it was pretty smooth water. I got it up to about 64mph trimming up. It's definitely something that takes time and experience to build your comfort level when going that fast. Didn't catch any fish though.