Trim level when boating

[Bobby Bass]

I have a 2023 150 HP Yamaha Sho-Max on my 2024 Bennington 21L. I have my trim level set at 50% while docked. I don’t raise the trim so the prop is safely in the water around the dock. My dealer had it set to 50% while boating too. I Wonder if I should lower the trim level, dropping it down lower, when I’m boating. I Don’t want to bottom out the prop but want to make sure it’s running at the correct trim level. The manual wasn’t helpful. My question is, what trim level do you use when running your boat?

 

[Jack M]

I adjust my trim while underway depending on conditions ,depth and speed . At WOT I am usually between 19 and 26.
At the dock mine is all the way up .

 

[Vikingstaff]

Totally similar to Jack. Docked on sea legs, I trim as far up as my turbo swing allows to keep prop out of the water. When docking I trim up to 14 on my gauge, maximum I can raise it and run the motor (due to how shallow the first 200’ outward from our dock towards deeper water). When slow cruising usually trim to 5 on my gauge. When adding speed, tubing etc it will vary as conditions, turns, weight distribution on the boat, etc dictate, but almost always in the 3-7 range on my gauge.

Now what my digital mercury gauge trim numbers equate to in regards to % of trim, I have no idea. Not a clue. However, in playing with trim, you should notice SIZABLE variations in rpms and speed at the same throttle input levels, especially when going rather fast or at WOT. Play around and find your sweet spots.

 

[Michiman]

I adjust my trim while underway depending on conditions ,depth and speed . At WOT I am usually between 19 and 26.
At the dock mine is all the way up .

I have a 2023 150 HP Yamaha Sho-Max on my 2024 Bennington 21L. I have my trim level set at 50% while docked. I don’t raise the trim so the prop is safely in the water around the dock. My dealer had it set to 50% while boating too. I Wonder if I should lower the trim level, dropping it down lower, when I’m boating. I Don’t want to bottom out the prop but want to make sure it’s running at the correct trim level. The manual wasn’t helpful. My question is, what trim level do you use when running your boat?

Trim gauges differ from brand to brand and boat to boat, with every boat I’ve owned being different. My current boat is totally trimmed up at 22 and I operate around 0, which is not all the way down.

As such, you need to experiment with your particular setup. 50% or half way up sounds way too high to me, but again, every boat is different. Personally, I’d start by observing where your engine is in relation to your gauge from all the way up to all the way down.

Most boats are going to perform best when the engine is almost fully down, depending on weight distribution (do you have a crowd in front??). As you raise and lower your trim, watch your RPMs (looking for the highest, to a point) to find your sweet spot. Too much trim and your bow is going to be down and too little and you will ventilate. Of course, the proper trim will also be dependent on what you’re doing (cruising or water sports).

All that said, the main thing to remember is that trim gauges vary. Your 50% might be equivalent to my 0 so that our engines are in the same position (but I doubt it).

 

[Potomacbassin’]

Trim depends on what you're trying to do.

Max out top speed? Trim the bow up almost to the point of porpoising.
Best fuel economy at cruise? Trim watching your fuel gauge to optimize MPG or GPH.
Going into turns to prevent ventilation? Trim bow down until you feel the prop "bite" better.
Going into a head sea with 4 foot waves? Trim bow up until you can skip across the wave crests.
Going into a following sea with 4 foot waves? Trim neutral to balance stuffing a wave vs. slapping the hull and giving your passengers a chiropractic bill.
Get in and out of sketchy shallow areas or areas with obstructions? Trim up almost to where you lose prime on your water pump watching tell tale.
Getting out of being stuck on a mud bottom? Trim all the way up even potentially past the point of losing pump prime to get back into deeper water and hoping no high temp alarm.
Running with your bimini up? Trim bow all the way down so the angle of attack of the bimini canvass is zero so it doesn't act like a sail.

If you're not actively trimming throughout the day you're possible leaving some performance on the table. Then again some could care less and/or go at speeds that negate over-thinking trim.

 

[Bobby Bass]

Thanks for the comments. My dashboard trim gauge is a needle gauge that just shows a range from left to right, so the needle pointing in the middle is 50%. The Yamaha manual notes to only adjust the trim when fully stopped, not when underway. So I adjust before putting the motor in gear. I have been adjusting to see if it makes a difference with performance and will continue to do so.

 

[Jack M]

Here are 2 numbers for Yamaha 888 352 1568 or 866 894 1626 .

I would check with them , that doesn't sound right . Unless they are referring to set up .

Thanks for the comments. My dashboard trim gauge is a needle gauge that just shows a range from left to right, so the needle pointing in the middle is 50%. The Yamaha manual notes to only adjust the trim when fully stopped, not when underway. So I adjust before putting the motor in gear. I have been adjusting to see if it makes a difference with performance and will continue to do so.

 

[Vikingstaff]

The Yamaha manual notes to only adjust the trim when fully stopped, not when underway. So I adjust before putting the motor in gear. I have been adjusting to see if it makes a difference with performance and will continue to do so.

I have never heard of “only adjust trim when fully stopped, not when underway”. That’s just, well, different. I guess it’s in your manual though. Edit: posted same time as Jack above. I’d call the number Jack provided in inquire directly with Yamaha.

Adjusting trim when underway is so standard, and with usage and water conditions, almost necessary at times to keep it operationally smooth for ride, performance, efficiency.

 

[Jack M]

I have a 40 minute no wake ride down a shallow river to get to 1 of the 2 lakes in my area , I have no choice but to trim ( 40 -55 on my Simrad ) during the trip . I drop it down when we hit the lake .

 

[BigKahuna]

Good example of the trim level on my Simrad. It's at 28% so a little over 1/4 trimmed up. 31.9 mph at 4420 rpm's on a Mercury 150. I trim down before/while making any turns!

 

[Toddk9]

I am with BigKahuna on this, little over 25% but i got a Yamaha and a needle gauge. If bigger waves, i will raise it little more to get the bow up higher. I leave it there most of the day except when coming into my lift, then it goes up to get into my hoist.

 

[LaurencetheAdventurer]

I have never heard of “only adjust trim when fully stopped, not when underway”. That’s just, well, different. I guess it’s in your manual though. Edit: posted same time as Jack above. I’d call the number Jack provided in inquire directly with Yamaha.

Adjusting trim when underway is so standard, and with usage and water conditions, almost necessary at times to keep it operationally smooth for ride, performance, efficiency.

My Benny has Auto Trim via the Simrad - it is constantly adjusting itself - love that it is one less thing I have to worry about, especially when towing.

 

[Vikingstaff]

My Benny has Auto Trim via the Simrad - it is constantly adjusting itself - love that it is one less thing I have to worry about, especially when towing.

I believe you and another member have talked about it before. I’d love to have that feature. Sounds very nice!!!

 

[Jack M]

I had the auto trim on my 2020 , I did not care for it . There is no way it can know the hazards of the river and I was able to get better speed on my own . Im sure many people like it , I could not justify it on my 2022 for my area and use .

 

[Vikingstaff]

I had the auto trim on my 2020 , I did not care for it . There is no way it can know the hazards of the river and I was able to get better speed on my own . Im sure many people like it , I could not justify it on my 2022 for my area and use .

A HUGE factor in trimming on our lake is many shallow areas that reach out very far into our lake. So, based on what you mentioned above, perhaps I’d be in a similar boat - Maybe not a practical feature for us based on lake conditions.

 

[LaurencetheAdventurer]

I believe you and another member have talked about it before. I’d love to have that feature. Sounds very nice!!!

Now if it could just figure out how to raise itself when those pesky sandbars sneak up out of no-where!!! LOL.