Fuel Gauge Intermittent 19% to 0%

[Miker1234]

Hey all!

I was coming in back from a great day on my 2022 2320, and noticed my fuel gauge on the Yamaha command link going from 19%, which is what was in the tank, to 0% a few times. It seem like an intermittent electrical issue from the sender. It was a pretty rough day out there it was bouncing from 19 to 0 in the harbor when the boat was stable.

Have any of you had this issue? Where should I start looking? I was going to check the cable connector from the sender to the command link and connections in between.

Please let me know if you have experienced this. Thanks!

 

[Mpellet]

I think if you’re relying on the accuracy of a sending unit fuel gauge and it’s reporting accurately down to 19% in the tank, your system is working well. IMO in a 100+ gallon fuel tank located in bouncing boat that operates on varying deck angles, a sending unit fuel gauge is at best a rough estimate of what you have on board. If you’re not already keeping a log of hours logged and how much fuel you’re adding at fill ups, it’s a good idea to start one. Eventually you’ll have an accurate data profile that you’ll know how much fuel you have on board just by noting how many hours you’ve logged since your last fill up. Obviously fuel consumption varies tremendously depending on how your operating your boat, as in one fill up featuring 10 hours of trolling is going to have a significantly different burn then 10 hours at high speed cruise but if you keep a record over time, it will average out and over time you’ll have very accurate #s. I have a 1000+ hours on my current engine and this engine provides very accurate #s for the amount of fuel it burns, typically with less then 1/2 a gallon of deviation from what it takes to fill the tank.

I have continued my written log and have come up with an average fuel burn of 5.5 gallons burned per operating engine hour (I do a lot of trolling). I am consistently less then 3 gallons off from what I think I have in the tank to what’s actually in the 150 gallon tank.

Folks go through a lot of trials and tribulations with sending units in large boat fuel tanks, when in reality, even why they’re operating correctly the acurracy of the data they provide is inherently inaccurate.

If I was having a new fuel tank built today, I wouldn’t even bother having a sending unit installed. What they’re best at is introducing an additional place for the tank to leak with the passage of time…

 

[Miker1234]

I think if you’re relying on the accuracy of a sending unit fuel gauge and it’s reporting accurately down to 19% in the tank, your system is working well. IMO in a 100+ gallon fuel tank located in bouncing boat that operates on varying deck angles, a sending unit fuel gauge is at best a rough estimate of what you have on board. If you’re not already keeping a log of hours logged and how much fuel you’re adding at fill ups, it’s a good idea to start one. Eventually you’ll have an accurate data profile that you’ll know how much fuel you have on board just by noting how many hours you’ve logged since your last fill up. Obviously fuel consumption varies tremendously depending on how your operating your boat, as in one fill up featuring 10 hours of trolling is going to have a significantly different burn then 10 hours at high speed cruise but if you keep a record over time, it will average out and over time you’ll have very accurate #s. I have a 1000+ hours on my current engine and this engine provides very accurate #s for the amount of fuel it burns, typically with less then 1/2 a gallon of deviation from what it takes to fill the tank.

I have continued my written log and have come up with an average fuel burn of 5.5 gallons burned per operating engine hour (I do a lot of trolling). I am consistently less then 3 gallons off from what I think I have in the tank to what’s actually in the 150 gallon tank.

Folks go through a lot of trials and tribulations with sending units in large boat fuel tanks, when in reality, even why they’re operating correctly the acurracy of the data they provide is inherently inaccurate.

If I was having a new fuel tank built today, I wouldn’t even bother having a sending unit installed. What they’re best at is introducing an additional place for the tank to leak with the passage of time…

Thanks for the great information. I’ve been tracking burned vs what’s in the tank and feel pretty good about it. My intermittent reading was bouncing from 19 to 0% in the harbor under calm conditions. I forgot to add it in the post. I edited it now.

 

[Andy]

I think if you’re relying on the accuracy of a sending unit fuel gauge and it’s reporting accurately down to 19% in the tank, your system is working well. IMO in a 100+ gallon fuel tank located in bouncing boat that operates on varying deck angles, a sending unit fuel gauge is at best a rough estimate of what you have on board. If you’re not already keeping a log of hours logged and how much fuel you’re adding at fill ups, it’s a good idea to start one. Eventually you’ll have an accurate data profile that you’ll know how much fuel you have on board just by noting how many hours you’ve logged since your last fill up. Obviously fuel consumption varies tremendously depending on how your operating your boat, as in one fill up featuring 10 hours of trolling is going to have a significantly different burn then 10 hours at high speed cruise but if you keep a record over time, it will average out and over time you’ll have very accurate #s. I have a 1000+ hours on my current engine and this engine provides very accurate #s for the amount of fuel it burns, typically with less then 1/2 a gallon of deviation from what it takes to fill the tank.

I have continued my written log and have come up with an average fuel burn of 5.5 gallons burned per operating engine hour (I do a lot of trolling). I am consistently less then 3 gallons off from what I think I have in the tank to what’s actually in the 150 gallon tank.

Folks go through a lot of trials and tribulations with sending units in large boat fuel tanks, when in reality, even why they’re operating correctly the acurracy of the data they provide is inherently inaccurate.

If I was having a new fuel tank built today, I wouldn’t even bother having a sending unit installed. What they’re best at is introducing an additional place for the tank to leak with the passage of time…

I'm in lock-step with you about keeping a log; we did so with our last two boats, for 31 years. The last boat (Diesel, with two 150 gallon fuel tanks) I kept a precise fuel-use log. I'll admit it was easier, as for the most part I ran at 1800 rpm's (slow cruise), or 2100 rpm (fast cruise) and average burn was only 1.9 gph. Plus, both tanks also had sight-gauges that were marked and calibrated, and all five tanks (two, 100 gallon water, and one 80 gallon holding-tank) are connected to a "Tank-Tender" air-pressure tank-monitoring system that monitored the levels in all the tanks; there is nothing electrical involved, that could 'go bad'.... With that said, I have not kept a log on our Parker. The reason (I know, bad excuse! ☺) is that is I top off the tank when it's about half full. Not a big issue with the 200 gallon tank on our 2520 XLD.

 

[Gsully23]

Hey all!

I was coming in back from a great day on my 2022 2320, and noticed my fuel gauge on the Yamaha command link going from 19%, which is what was in the tank, to 0% a few times. It seem like an intermittent electrical issue from the sender. It was a pretty rough day out there it was bouncing from 19 to 0 in the harbor when the boat was stable.

Have any of you had this issue? Where should I start looking? I was going to check the cable connector from the sender to the command link and connections in between.

Please let me know if you have experienced this. Thanks!

Check the connections at the sender (if it's a Deutch, make sure the pins are clicked/locked in). Wiggle it, see if you can replicate it while watching the gauge. Next, your going to check the harness right behind your dash. Make sure the pink and yellow from the sender are firmly plugged into the yamaha harness. These should be "banana" plugs and just push to connect. Make sure there tight, pinch them some if you have to.

If the gauge was intermittently reading full, it would mean that circuit is grounding out. With it intermittently reading 0, it usually means open line.

Also, the yamaha gauge has about a 10-15 second delay when you manually move the sending unit up or down to check, it's doesn't register immediately fwiw.

 

[Miker1234]

Check the connections at the sender (if it's a Deutch, make sure the pins are clicked/locked in). Wiggle it, see if you can replicate it while watching the gauge. Next, your going to check the harness right behind your dash. Make sure the pink and yellow from the sender are firmly plugged into the yamaha harness. These should be "banana" plugs and just push to connect. Make sure there tight, pinch them some if you have to.

If the gauge was intermittently reading full, it would mean that circuit is grounding out. With it intermittently reading 0, it usually means open line.

Also, the yamaha gauge has about a 10-15 second delay when you manually move the sending unit up or down to check, it's doesn't register immediately fwiw.

I’ll try it! Thanks for the info!