Outboard too high??

[Herkguy]

I have heard a lot of stories about people having to raise their outboard to get the most out of it. I think I may be the opposite?

I have a 2020 Harris Solstice 230 with a Mercury Verado 250 on it. Top speed I have gotten is 42mph. I feel like it should go faster. The weird thing, is that to get that speed, I need to trim the engine all the way down. If I trim it up at all the boat slows down. The motor is in the second highest position, I am thinking about lowering it two holes. Thoughts?

[Marc K]

How high is the cavitation plate compared to the bottom of the motor transom pod?
What is your RPM running wide open at 42 MPH?
What change in RPM do you see when you trim up and the boat slows down?
Do you see some bow rise when trimming up?

Marc

[MattGent]

Record and plot your rpm and speed for every 500rpm. With your gear and prop you can calculate slip. If it is rising at higher speeds, need to lower engine or pick a prop with more blade area.

[Herkguy]

Thanks for the responses! I am around 6000 rpm at WOT and 42mph, trimmed fully down. I haven't looked at what happens to the RPM when I trim up so I will have to look.

I showed it to a couple techs at my dealership yesterday and they both immediately said it was too high...

My prop slip with the verado gear ratio of 1.85 is at 42mph is 15, which seems really high???

[willy13]

What prop do you have?

[Herkguy]

It's a Mercury Enteria, 14.7x16P

[willy13]

That's a fantastic prop, so you might need to play with outboard height. 15% slip is on the high side, not crazy high, but high for the enertia prop. I am getting 6% slip with a 15 pitch enertia on a tritoon with a 200 HP v6 four-stroke. Top speed is 42 at 5800 rpms.

[Herkguy]

Just got off the phone with dealer and they are lowering it to the second lowest hole (from the second highest) first thing tomorrow morning! I'll let y'all know. Excited to see the difference!

[Herkguy]

Lowered two notches. Boat trims like its supposed to now, needing a few seconds of "Up" after we get going. Top speed went up 1mph but that was with a full tank (63gal) of gas so I bet we can do better.

Thanks for all your responses.