tilt/trim drive questions

[Dave S]

Others will correct me if I am wrong but I would think cruising around at cruise speed most of the day at 3/4 up is too far. Interested to see what others think.

Wesley

The trim limit switch protects you from putting the outdrive too far up thereby putting unnecessary strain on the driveline and the u-joints in particular. Mercury has designed that out drive so if necessary you can run with the outdrive tilted as far up as the trim limit will allow. Keep in mind though that each boat hull will respond differently to trim. My 260DA requires almost full trim (to the limit) to plane smoothly in what I call the "sweet spot" where you get the best speed out of the boat at any given RPM. My 240SD on the other hand required very little trim to get to the sweet spot and in fact if you put the drive up to far it would cavitate (or suck air rather than water) and cause the engine to over-rev.

Everyone should find that "sweet spot" for their boat and whether that means the drive is trimmed just a tad or most of the way to the trim limit then thats where you should run it for your boat. Loads (or how many people are in the boat) may affect that a bit but generally speaking the amount of trim you need for cruising along remains the same regardless.

 

[GJarrett]

I'm also thinking there's a lot of posting about apples and oranges when I read "1/4 way up or down" and "3/4 up" etc. I know I've had my trim sensor replaced and I've adjusted it and I have a strong suspicion that what may read "1/4" on one gauge is nowhere near what it means on another boat.

That brings us back to what's already been stressed a few times in this thread. You need to learn how to find the "sweet spot" for your situation and dial the trim into there. I'd almost want to suggest covering up the dang trim gauge and ignore it so you can learn how to trim without that crutch.

Just my extry peso's opinion, but may be wrong.

 

[Dave S]

I'm also thinking there's a lot of posting about apples and oranges when I read "1/4 way up or down" and "3/4 up" etc. I know I've had my trim sensor replaced and I've adjusted it and I have a strong suspicion that what may read "1/4" on one gauge is nowhere near what it means on another boat.

That brings us back to what's already been stressed a few times in this thread. You need to learn how to find the "sweet spot" for your situation and dial the trim into there. I'd almost want to suggest covering up the dang trim gauge and ignore it so you can learn how to trim without that crutch.

Just my extry peso's opinion, but may be wrong.

Agreed.............it's more important to go by feel. My boat becomes noticably smoother when trimmed properly. Besides the trim gauge on my Smartcraft equipped 260DA is totally useless anyhow since it doesn't really show the trim position properly. At least the ones on my 210SD and 240SD worked properly. :smt101

Dave

 

[midway]

The way I found the spot I trim to was trim up a little and watch the speed, as long as I got a little faster each time I would go up more, there is a point that I don't go faster and may lose a little, I know where to stop on the gauge from that. Gerald is right, learn to trim for best results, see where it is and you can use that in the future.

 

[brian2001ss]

Brian

Trimming the drive serves one purpose and that is to get the boat out of the water thereby reducing the "wetted" (or friction) surface which gives you the best speed and burns the least amount of fuel to boot.

On my 240SD I could tell when it was trimmed perfectly just by watching the speedometer. You could actually see the boat pickup a bit of speed when trimmed properly or loose speed when not trimmed properly. In rough water conditions you may want to trim the drive down so the bow of the boat cuts thru the waves instead of slamming over them with a bow up attitude. When first starting out the drive needs to be trimmed down to give you the fastest time-to-plane.

There really isn't any more to it than that unless you have trim tabs........but thats another story.

Dave

Thanks Dave.

I just may make an early trip out on the lake this weekend just to see what the different trim settings make on a calm lake early in the morning. It seems to be geared toward what your boat likes, rather than this is what it should be. Also, good to hear I can trim it all the way up and not be harmful to the drive.

Great discussion guys!!

 

[hoosier daddy]

Every boat is different when it comes to trim position.
Trim at 1/4 on boat "A" does not mean trim at 1/4 on boat "B" will produce the same results.
You have to learn to "feel" the proper trim position (for your boat) through trial and error.
Unless the limits have be changed you cannot over trim (harm the lower unit) using the buttons (not trailer) on the throttle.
Your boat will tell you when you have went to far.
The prop will blow out (cavitate) or it will start to porpoise.
Listen to the motor, watch the tach and speedo it will all smooth out when it's right.
Less boat in the water equals less drag, more speed, better economy (unless at WOT), less spray.
I routinely run the trim to 3/4 (upper limit) on smooth water.
Almost always at 1/4 (even rough water) unless pulling skiers up or tubing.
Using trim tabs is a huge benefit also.
Its a dynamic thing you cannot Set It and Forget It.

 

[First Born]

ok now for a dumb question but I am learning something new on this thread as well. When you say trim level switch will not prevent you from going past an acceptable position are you talking about if you have two trim switches. My understanding of mine (I only have one) and I have never tried it in the water for obvious reasons is that i can hold the button down all the way to the trailer position while the boat is moving.

Like Brian looks like it is time for me to play around with mine and make sure I am stopping at the right point and should not be trimming up more.

 

[chuck1]

..... When you say trim level switch will not prevent you from going past an acceptable position are you talking about if you have two trim switches. My understanding of mine (I only have one) and I have never tried it in the water for obvious reasons is that i can hold the button down all the way to the trailer position while the boat is moving.

Newer boats have one switch. Push the toggle switch up and your trimming up. When it stops you push the toggle switch up harder you're now in the trailer position of the drive. I've never tried it with the engine running either.

 

[billandamy]

Newer boats have one switch. Push the toggle switch up and your trimming up. When it stops you push the toggle switch up harder you're now in the trailer position of the drive. I've never tried it with the engine running either.

I did that once, right when we got the boat. I put it in reverse after dropping it into the water with engine all of the way up. Luckily it was just in the first throttle position so no damage.

I read the manual shortly after again, and there is a big warning about putting it into gear at all in trailer position, and a big warning not to exceed a certain rpm at its highest trim levels.

 

[ruf1967]

ok now for a dumb question but I am learning something new on this thread as well. When you say trim level switch will not prevent you from going past an acceptable position are you talking about if you have two trim switches. My understanding of mine (I only have one) and I have never tried it in the water for obvious reasons is that i can hold the button down all the way to the trailer position while the boat is moving.

Like Brian looks like it is time for me to play around with mine and make sure I am stopping at the right point and should not be trimming up more.

Wes,

I have the same boat. Did you ever notice there is a noticable "click" when you fully depress the tilt/trim switch? That allows you to tilt past the trim limit. If you only press it partially, the outdrive will only trim up to the trim limit and stop, if the mechanism is working correctly. It's similiar to the way a digital camera works. When you press the shutter button partially, it allows the camera to focus, press it fully and you take a picture. I've never actually trimmed fully up while the boat was underway because it really goes a little to far and the prop starts to slip.

 

[Woody]

There is obvious confusion here with the terminology trim/tilt/trailering position.

 

[gruz1]

I did that once, right when we got the boat. I put it in reverse after dropping it into the water with engine all of the way up. Luckily it was just in the first throttle position so no damage.

I read the manual shortly after again, and there is a big warning about putting it into gear at all in trailer position, and a big warning not to exceed a certain rpm at its highest trim levels.

I've been trailor tilting lately when I launch because the spot I put in is between 2 and 3 ft of water, will this damage anything? I hit a rock about a month ago and have had to trim it higher then it would normally go to avoid the rocks.

 

[midway]

You are not supposed to do that, I have a place in the creek behind my house that when the water is near low tide I have to go to trailer position to clear something very hard under water, I do this at idle until I see whatever pass on my fish finder screen then back to normal trim, I sometimes have to idle away from the beach in trailer position, it is always just a few feet then trim down. Probably if I was in your position I would idle away from the ramp to clear the rocks also.

 

[Woody]

This from my Merc manual: Power trim allows the operator to adjust the sterndrive angle while underway, to provide the ideal boat angle for varying load and water conditions. Also, the trailering feature allows the operator to raise and lower the sterndrive unit for trailering, beaching, launching and low speed(below 1200 rpm engine speed), shallow water operation.

 

[chuck1]

As others have said and per the manual.

The trailer switch is to be used only when the engine
is OFF.

Tilting drive unit into trailering zone
while underway can damage the drive unit or engine.

IMHO - If you ever had a warranty issue with your drive unit/engine I would think merc would not allow it since they say it can damage the drive unit or engine. Only to be used when the engine is off.

 

[Woody]

Does your manual actually say only when the engine is off? I think the term "underway" is the key here. Mine says what I posted earlier. I agree with not doing it, I am just comparing manuals.

 

[gruz1]

I guess I'll have to take my chances with trailer mode because I'm sick of having to rebuild props. Full trim is about 28" draft and when I use trailer mode I just bring it up to about a 20 to 24" draft. Unfortunately I have to keep it there for about a quarter mile.

 

[chuck1]

Does your manual actually say only when the engine is off? I think the term "underway" is the key here. Mine says what I posted earlier. I agree with not doing it, I am just comparing manuals.

Yep that is a direct copy/paste from the PDF format of the 2006 240SD Manual.

I read or heard some where that even if you are not in gear the shaft is still turning and it would put a strain on what I call the universal joint. Made sense to me, so I've tried to make sure I never even started it in the trailer up position. I did it once when it was launched via a lift system from the trailer and the drive made a terrible noise for about 3 seconds before I could turn the engine back off.

 

[chuck1]

I guess I'll have to take my chances with trailer mode because I'm sick of having to rebuild props. Full trim is about 28" draft and when I use trailer mode I just bring it up to about a 20 to 24" draft. Unfortunately I have to keep it there for about a quarter mile.

I've been trailor tilting lately when I launch because the spot I put in is between 2 and 3 ft of water, will this damage anything? I hit a rock about a month ago and have had to trim it higher then it would normally go to avoid the rocks.

Maybe it is just me, but can't you find a different place to launch?

 

[billandamy]

I've been trailor tilting lately when I launch because the spot I put in is between 2 and 3 ft of water, will this damage anything? I hit a rock about a month ago and have had to trim it higher then it would normally go to avoid the rocks.

It says in the manual not to engage the gear in this position. I did it that one time not realizing it, but no damage. I had JUST popped it into gear, but didnt accelerate.

I launch in similar conditions, and nothing has ever happened. I leave the trim almost all of the way up, and just pop it into gear but dont accelerate. We are shallow sometimes in the 3' range as well.