Repowered Key West 219fs Suzuki DF200AP - Fuel Level Confusion

[Mr. Shaky]

I just bought a 2016 Key West 2019fs with a 2018 Suzuki DF200AP. It has a C10 and a Simrad Go9. Incidentally, there were two NMEA networks in the boat when I got it, but after a bunch of reading about that, I joined them.

The boat is supposed to have a 90 gal tank. It said there was 57 gal when we bought it so we used it for several trips without adding any. Fuel level was dropping as expected, then my sons took the boat out for a ride and when they got back it says there's about 1.5 gal left, which was a big drop. By rocking the boat a bit I could make it toggle between 1.5 and around 10, but if the gauge says empty I'm not leaving the dock, so we added fuel.

I added 21 gal, and immediately entered that when the C10 asked if we added any fuel. Now it says there's 52 gallons. The only math that makes sense is if it had 10, and took my addition of 21 twice. But I'm pretty sure I didn't screw up the entry like that.

The boat does have a level sensor (KUS SSS 10). I can see the data from it on the C10 - it says the Device Information is a Lowrance Model 1.0.0 Software 1.3.0-MZ1657C-B1.0

I understand the measured vs calculated fuel subject, but am not sure if the level I'm looking at is measured or calculated. I suspect it's measured because the tank sensor data in Network Device Information shows over 50%. I can't find where to see calculated fuel level.

Is calibration possible without emptying and filling the tank completely?
Is it possible to un-do the 21 gallon entry I made?

I've been scouring the Key West, Suzuki and The Hull Truth forums for info on my fuel dilemma and see expert postings all over from Moonlighter.

I really appreciate your help!

[Moonlighter]

Ok, first questions- did you remove one of the power supplies when you joined the 2 networks? Very important to do that, or alternatively put a power isolating T between the two halves.

The difference between the measured (eg from the fuel sender unit in the tank) and the calculated level (from the engine) is that they are shown differently on the gauges - calculated will show an actual number of gal left, whereas measured shows a % result. Look in the middle of the gauge for the units as gal or %.

Anyway I would recommend a fresh start, when you buy a used boat its impossible to know what the PO has done to the network.

To do this and get it right, you must go and fill the tank to full after doing the setup.

This can be done on the C-10 or on the Simrad GO, either one is fine. Following procedure is for the GO but C10 is basically the same.

Turn key on. In the Simrad menu, select settings then scroll down to fuel, and select that. Then select vessel setup, there you will see the boat and tank arrangement, so make sure it is set to match what your boat has - eg if your boat has 1 engine and 1 tank, use the dropdown to set it as that. Then check that the tank capacity is set correctly as 61 gal if indeed that is what the manufacturer says that the tank holds. Then go back to the fuel menu, and check the set to full button. (DO NOT input any figure into the screen for fuel added!!) This resets fuel used to zero and fuel remaining to the same amount as the tank capacity was set to earlier. Exit from the fuel menu.

Now go to menu/system/network/device list, and select the Suzuki engine. Select configure. Check to make sure that the engine location is set as Centre, as it should be centre for a single engine boat. That is all to do on that page. You cannot change the engine year and hp so dont try. They are set at the engine family level and the ecu release year so dont be concerned if that doesnt match exactly with your engine.

Now, as mentioned earlier, go and fill the tank up. Full. Dont reset fuel again.

Lets leave the tank sender calibration for now, it is usually pretty good out of the box. So just leave it at this stage, and keep an eye on how the tank sender “measured” data matches up with the “calculated” data from the engine interface.

Now, I always recommend for new installs that you verify the accuracy of the “calculated” fuel data, and there is only one way to do that, and it is as follows. So I recommend that you do this. You have already done step 1 of the procedure if you follow my above instructions, so dont repeat it.

This is the process to verify the accuracy or your Suzuki fuel data. It is only used for fine tuning when actual vs predicted is within about 10%. Variations greater than about 10% indicate another issue and its very unlikely that this calibration process will fix such issues.

Fill the tank to full at regular gas station and remember which pump you use. Reset fuel to full.

1. Go fishing and burn at least 1/3 tank, the more the better.
2. On the way home from the fishing trip, Go back to the same gas station and same pump if possible and fill up, try to fill to the same fullness as last time. Do not delay and leave it for weeks because evaporation from a partially filled tank can be considerable - experts say up to 5% per week in some conditions! Then compare the actual fuel used to what the Suzuki system says. If its more that 2% different, you should calibrate. To do this:
3. Turn the engine key to on where it beeps. Go into the fuel menu and select refuel. Then select set to full, and then hit enter and then select the option to calibrate. Select the engine to calibrate. Then when prompted, input the actual amount it took at the pump to fill up, and complete the process. It will pop up a notification that the K factor is changing to a new value. This K value is the calibration factor. Accept and finish.
4. You will probably have to complete this process 3 or 4 times to get within 1-2% accuracy. Once you get that close, leave it alone because variations then are more likely to be due to filling the boat at different gas stations where the angle of boat/trailer affect how much fuel goes into the tank, or inaccuracies in the pumps.

[Mr. Shaky]

I really appreciate the really thorough advice! Sounds like a great plan. I'll do it and let you know how it turns out.

I did a lot of reading about the NMEA network and indeed removed the 2nd power and one of the tees.