SMG4 Fuel Gauge Issue

[palmettores]

I have what I believe to be the SMG4 paired with a DF90. I have a 24 gallon tank. The fuel level is not accurate. I drained the tank and thought when I chose Tank Reset under the Initial Settings function I’d be able to re-establish zero and the various levels to full but did not get that option. All I can do is enter the capacity and OHMs (chose US).

Anyone know how to reset or correct this?

This weekend I had used 15 gallons and it was showing over 1/2 tank.

The fuel used is not super accurate based on filling, using and refilling but its close enough I suppose. But I want to be able to just look down and have an accurate reading of fuel level.

Thanks

[Moonlighter]

Here is a link to the SMG4 installation manual. Includes instructions for tank setup.

https://www.dropbox.com/s/u2fa08g7nw...glish.pdf?dl=0

[palmettores]

Thanks. I think I found what I wanted under the Tank Calibration then Custom option. Basically looks like that’s were you tell it empty, 1/4, 1/2 etc vs just selecting the US OHMs setting.

[Matt Ostrem]

So I read the same manual when I installed my SMG4 and wondered if it will work without a fuel sender from the tank. Is there a way to tell it that the tank hold 65 gallons and as it shows fuel burned it will also show fuel level going down?

[Moonlighter]

So I read the same manual when I installed my SMG4 and wondered if it will work without a fuel sender from the tank. Is there a way to tell it that the tank hold 65 gallons and as it shows fuel burned it will also show fuel level going down?

No.

SMG4 simply shows how much fuel has been burnt since the last reset of fuel data.

Fuel used - Yes.
Fuel remaining - No.
Fuel gauge - only if connected to a electric tank sender.

[Matt Ostrem]

Thank you for the clarification.

[slow530]

Palmettores - l reached the same conclusion going through custom. My tank is 150G. I plan to pull the sender (WEMA brand) and slide the float through the positions. Ran out of fuel a few weeks ago and had to get towed in. Showed 1/4 tank. Can’t have that happen again.

[Moonlighter]

Palmettores - l reached the same conclusion going through custom. My tank is 150G. I plan to pull the sender (WEMA brand) and slide the float through the positions. Ran out of fuel a few weeks ago and had to get towed in. Showed 1/4 tank. Can’t have that happen again.

Surprising to hear that!!

Do you reset fuel used on SMG4 when you fill up? Then you would know exactly how much fuel used, and by some simple mental arithmetic, how much you have left??

[slow530]

Hi Moonlighter - thanks for all your help here. I have never filled up. It’s 150 gallons on a 23’ boat, over 900 lbs. Gives me good range but I never go that far. Could I pull the sender and slide the float to full then reset the gauge? Right now the gauge shows full when I have half a tank.

[Moonlighter]

Hi Moonlighter - thanks for all your help here. I have never filled up. It’s 150 gallons on a 23’ boat, over 900 lbs. Gives me good range but I never go that far. Could I pull the sender and slide the float to full then reset the gauge? Right now the gauge shows full when I have half a tank.

Yes, you could do that and go thru the setup procedure.

I understand the reluctance to fill the big fuel tank to full. But if you do it just once, then keep a notebook from then on to track fuel added etc, then you would have pretty accurate fuel remaining info. Just an option to consider.

Another option - if you have Simrad electronics on board - is to network them via NMEA2000 to the SMG. And then also add a Simrad Fuel Data Manager device to the network.

This will give you fuel used, fuel remaining on the Simrad, and will allow you to add x gallons on the Simrad when you refuel rather than resetting to full.

What the Simrad does is to take the raw fuel data (fuel flow rate) from the SMG and use it to calculate fuel used, fuel remaining and trip and seasonal fuel, all of which is stored in the FDM device. It also opens up the Simrad TripIntel feature on Simrad displays that gives you a heap of very neat fuel and related data for each trip.

[slow530]

Circling back on this - The 240-33 ohm setting did not display correctly on the gauge. Under tank calibration I selected custom. I then pulled the tank sender, grounded the flange and went through the empty, 1/4, 1/2, 3/4, and full calibration sequence by positioning the float on the sender tube. I had already configured the tank size to 150 gallons. My previous gauge setting showed 7/8 tank with 65 gallons. Now with 65 gallons the gauge shows just under half as expected. If I add 10 gallons I expect to see half a tank. All other fuel related functions work as before. Will confirm this weekend. I do keep track of gallons burned and reset to zero before each trip. I have a Garmin 840xs that allows me to add fuel to keep a numerical amount of fuel on board.

IMG_1733.jpgIMG_1732.jpgIMG_1731.jpg

[Moonlighter]

Circling back on this - The 240-33 ohm setting did not display correctly on the gauge. Under tank calibration I selected custom. I then pulled the tank sender, grounded the flange and went through the empty, 1/4, 1/2, 3/4, and full calibration sequence by positioning the float on the sender tube. I had already configured the tank size to 150 gallons. My previous gauge setting showed 7/8 tank with 65 gallons. Now with 65 gallons the gauge shows just under half as expected. If I add 10 gallons I expect to see half a tank. All other fuel related functions work as before. Will confirm this weekend. I do keep track of gallons burned and reset to zero before each trip. I have a Garmin 840xs that allows me to add fuel to keep a numerical amount of fuel on board.

IMG_1733.jpgIMG_1732.jpgIMG_1731.jpg

Excellent work.

Good that the Garmin can do the fuel data too. Thats helpful.

Enjoy the new setup!