Trim indicator shows huge movement

[champdds]

I have a 2006 240SD, and previously posted a thread detailing that my SMARTCRAFT trim indicator would constantly indicate changes in position, making it difficult to monitor the depth, ie 2-3-2-3-2, etc as the position kept changing slightly, some thought it may be a fluid level problem, and I actually forgot about it until today, where NOW the SMARTCRAFT guage AND the analog guage are moving a lot, showing tremensous swings in position...So I checked the fluid, and the fluid level was just above MIN, when checked at the LOW position, so I added fluid as recommended..

This did not help at all, when we accelerate, the analog guage swings up to almost the max up position, and is bouncing all over the place (the digital readings move 2-4-6-8-6-4-3-2 etc) as we hit waves and I am worried something is loose somewhere and allowing the huge fluctuations now..My wife says she feels the prop/engine sounds different when it is doing it...

Thoughts ?

David:grin:

 

[240da]

Based on your very low fluid level I would guess you may have air in the system. As air is quite compressible it can cause a myriad of issues. I would lower the unit all the way and fill to the proper level and operate full up/down a few times to purge the air and see if the issue clears.

 

[champdds]

Based on your very low fluid level I would guess you may have air in the system. As air is quite compressible it can cause a myriad of issues. I would lower the unit all the way and fill to the proper level and operate full up/down a few times to purge the air and see if the issue clears.

I'll put it on the rack this weekend and do that...To clarify, the level was still within Min/Max, but I filled it to the Max level to be sure...

 

[Lazy Daze]

While you got it on the rack, run it up and down while someone watches the drive and the senders on the side of the drive. Try moving the senders by hand, as well. Could just be a bad sender, too.

Does the boat seem to operate correctly?

 

[champdds]

While you got it on the rack, run it up and down while someone watches the drive and the senders on the side of the drive. Try moving the senders by hand, as well. Could just be a bad sender, too.

Does the boat seem to operate correctly?

Sorry to be naive, I'll google what a 'sender' is...my wife (who has better ears) says she thinks it sounds different..

David:grin:

 

[Fishnut]

My analog reads in the middle of the range when in fact the smartcraft indicates about 5%

Not to highjack the thread, but my fuel guage on the smartcraft reads much more fuel in the tank while underway as opposed to at rest. Last night I was reading 3% fuel at the dock and I took off to fuel up and it went to 11%. I was wonder what accounts for this. I almost crapped my pants seeing 3%, i.e., 2.25 gallons v 8.25 gallons of fuel for a 3 gallon run to the pump.

I know, i know, I shouldn't be running that low on fuel. :lol:

 

[Lazy Daze]

Sorry to be naive, I'll google what a 'sender' is...my wife (who has better ears) says she thinks it sounds different..

David:grin:

No problem. You can probably find a bunch on threads on this forum about them, as well. Look for Trim Sender and Trim Limit.

They both look the same, with the exception of what they say on them. They are located on either side of the gimbal housing (what the drive sits in).

Fishnut: I would think it's just due to the angle of the boat - while underway is different when at rest. But to be honest, I don't know enough about that aspect of Smartcraft to know if it's able to compensate for that effect.

 

[Fishnut]

You're probably right but Searay market's it as this ultra accurate gauge system. Don't know, I may need to do some research.

 

[Moose]

Check the gimbal housing. If it's loose, like an inch of movement, this will affect your trim readings. Last time I had boat hauled for bottom painting, MarineMax said I had excessive movement. They tightened and now everything is OK. No trim tab movement!

 

[larryp]

Good morning fishnut,
Re: Smartcraft fuel gauge
Check the location of the sending unit on your fuel tank, forward, mid, aft. Also, check the location of the fuel pick-up. It sounds like the sending unit is located in the aft section of your tank. Check the shape of your tank, too. These will all have an effect on your readings.

 

[champdds]

Just a little update (almost 3 years later)....while my mechanic has never really solved the issue when I am getting other things checked, the problem has been very sporadic and really not repeatable, until I noticed something yesterday while out on the lake. It seems that when I usually lower the unit down, via the throttle control rocker switch, and go to when I hear the mechanism start to sound strained..I stop....well yesterday we are cruising along just fine, when the Smartcraft display starts showing the unit position going up and down, 1-2-3-4-5-4-3-2-1, back and forth...which makes it absolutely impossible to try and read and toggle between any other data on the dispplay, since it always overrides the display when the trim changes....so, I gave one short bump on the throttle rocker switch up, and 'viola'...no more crazy position changes on the display, and all is well....any thoughts???

David

 

[scoflaw]

With the trim all the way down, you did set your trim value to 0, right?

 

[champdds]

With the trim all the way down, you did set your trim value to 0, right?

I have actually never set the value, just what it came as factory setting I assume....It worked well the first few years we have had it and I have never changed anything....should I recalibrate it, is that what you are saying ? The analog indicator also moves up and down as well....when it is acting wacky..

David

 

[kaz911]

My analog reads in the middle of the range when in fact the smartcraft indicates about 5%

Not to highjack the thread, but my fuel guage on the smartcraft reads much more fuel in the tank while underway as opposed to at rest. Last night I was reading 3% fuel at the dock and I took off to fuel up and it went to 11%. I was wonder what accounts for this. I almost crapped my pants seeing 3%, i.e., 2.25 gallons v 8.25 gallons of fuel for a 3 gallon run to the pump.

I know, i know, I shouldn't be running that low on fuel. :lol:

that is normal behaviour. your fuel indicator is only precise when boat is level. And even then it is not quite. Have you calibrated your fuel tanks/smart craft instrument?

I had same issue on my 210 Select (2009) - but after a good calibration it was better. But I got used to checking the tank visually.

Check out this SmartCraft calibration video: http://www.mercurymarine.com/gauges-and-controls/video/gauges-and-controls/SC1000-Calibration/

What happens is that once you are on the way - boat is not level - so fuel is "pushed" to the back of the tank. And there are not "enough" fuel senders to measure that tank imbalance. And then the tank is not square. So if the tanks are not calibrated the fuel senders have just a "generic" linear measurement - and that does not work very well when the tank is not completely square.

First thing to figure out is the total capacity of your tank. Don't trust the brochure! Mine was supposed to be 146L in the brochure - but in real life it was about 166L. So when you filled tank and it was at 3% - used that or brochure indication as your first "calibration target" (whichever is highest) - then next time you are at 3% then calibrate from there.

The RIGHT way is of course to get the tanks completely empty and calibrate from there. But that requires you to pump out the tanks completely and be by a gas station to fill it.

I calibrated mine 3-4 times before I was happy with the result. And if someone resets your SmartCraft (installing new SmartCraft gauge etc) - then you need to do the calibration again.

 

[kaz911]

Just a little update (almost 3 years later)....while my mechanic has never really solved the issue when I am getting other things checked, the problem has been very sporadic and really not repeatable, until I noticed something yesterday while out on the lake. It seems that when I usually lower the unit down, via the throttle control rocker switch, and go to when I hear the mechanism start to sound strained..I stop....well yesterday we are cruising along just fine, when the Smartcraft display starts showing the unit position going up and down, 1-2-3-4-5-4-3-2-1, back and forth...which makes it absolutely impossible to try and read and toggle between any other data on the dispplay, since it always overrides the display when the trim changes....so, I gave one short bump on the throttle rocker switch up, and 'viola'...no more crazy position changes on the display, and all is well....any thoughts???

David

Trim senders can go bad - and a just a loose connection or one damaged one will give all sorts of readings. First test if they are loose. If not just replace them and the trim wire harness at your next service. I had one set replaced during warranty and one set after warranty on a 2009 boat. They are not really expensive.

Once replaced get the mechanic to calibrate them (see my previous post on smart craft calibration)

and Analog gauge vs digital gauge - the first 10% trim is the "large space" on the indent on your analogue gauge. The last markers up to red (very small space) is from 10%-25% - since that is "trailer position" - So 5% in the middle of the large space is correct.