Well, why don't you start by telling what kind of boat and what motor you have?
FWIW, I just set my trim by listening to the motor and watching the bow. There's a sweet spot you'll get a feel for, but depending on what motor you have there are peobably more options.
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2008 Sea-Pro SV1900CC with 150 Optimax
The trim gauge does not tell you where to set the trim -- all it does is tell you the engine is all the way up, all the way down, or somewhere in between without turning your head to look. The seat of your pants, the tach, and speedometer tell you when trim is properly set. Depending on water conditions, load, speed, etc., trim is never a constant so what good does the gauge do other than tell you "where" the trim is currently set.
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what good does the gauge do other than tell you "where" the trim is currently set.
yep, that's what i want to know. my trim don't work though, only my trailer. other than that, for my own reason on my drive, every thing st says is where it's at. the tach is your friend when trimming proper for sure....
last resort. i've read some folks puttin a stick or the likes on the drive. that way ya can look back and see the angle of the stick..... pretty low tech idea, but swear i've read it more than once before....... i like a gage.....
I agree with all above with one exception . . . It is nice to have a trim gauge if you run an I/O in shallow water, beaching, even launching. I use it simply to take a peak at when I am idling through a shallow marina etc. I want the angle of my drive to be such that the bullet and skeg will take more of any low speed impact than the prop . . . OB you can see the power head usually to determine the angle of the prop for startup and shallows.
Edit: A solution is to count while you press the button and then see what change a count to 3 is for example. It's easy to know when you are all the way up, or all the way down. So count from there to a spot for say loading on the trailer etc. Important if your skeg can hit the ground while on the trailer . . .
At cruise, I get the trim in the ballbark, and then use the gps to find the optimal speed for the given RPM. Small corrections up or down till the gps reads the highest. I memorize approximate speeds for certain RPM settings, like 2800 rpms usually gives me 21.5 mph. If its reading low, then I need to adjust.
When launching and in shallow water, I trim the drive all the way UP and then lower it just enough that the prop bites and the sound splashing water disappears. I believe that's the highest the drive could be, and still be effective. I could be off on my techniques, but it works for me.
Well, I went ahead and searched your posts to see what boat and motor you have...
Unless I'm wrong, you can get a Smartcraft gauge from Mercury that will show among other things the position of the motor. I've been looking at them myself and that was one of the main features I wanted as well. The Optimax 150 is a supported engine.
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2008 Sea-Pro SV1900CC with 150 Optimax
When launching and in shallow water, I trim the drive all the way UP and then lower it just enough that the prop bites and the sound splashing water disappears. I believe that's the highest the drive could be, and still be effective. I could be off on my techniques, but it works for me.
My .02
I was cautioned against running my I/O that high because of the angles of the ujoints in the drive shafts. I don't know if that was bunk or not, but I never ran mine any higher than the 1/2 click trim would take it.
You also have to make sure the water pickup stays in the water deep enough as to not run the motor hot when you trim up that high.
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2008 Sea-Pro SV1900CC with 150 Optimax
This is commonly misunderstood ^^^^^^ Mercruiser allows operation up to 1200 RPM at any tilt position, full power between the very bottom and the high "trim" limit. That doesn't mean it's good, but if necessary and the water intakes are underwater, then Merc says do it. My skeg on my Bravo is slightly below my hull at full "trim" height. If I am in extremely shallow water I will idle around above that point, because I know that my hull will slide along the bottom without the skeg or prop hitting anything. If there is no reason to run that high, then don't. If there is a reason like shallow etc., then Merc and I say OK . . . Yes, I may wear my u-joints out 3 hours before someone else who changes there's at 776.3, but I am OK with that risk . . .
I am a little confused, I like to use "the seat of my pants, tach, GPS" to find best trim, but why on earth would you not want to easly find that spot without hunting??? I have smartcraft, and mine automatically pops up if I toggle the trim, it displays to 0.1 degrees, I stomp on it out of the hole, and on the way to plane I trim to what I know is ideal and forget about it... very convenient. I know it changes with your load and balance, but typicaly I run similar weights, I'm sure we all do.... just my .02.
No trim guage on new boat.how do I know/
Linear Mode
