Yamaha 2021-2023 Low Fuel Alarm, Reduced Fuel Tank capacity?

[Mr. GP1800]

Do you guys think inserting a simple Arduino module in between the sensor and the touch screen could solve the problem?
The Arduino could modify the signal so that when the tank still has fuel, the touch screen is made to think the fuel level is still good.
I haven't looked at the connectors yet... I will try to do that this weekend.

I have been trying to source these connectors for a while. I have a company looking into getting them. I think the issue is the way it’s keyed. It’s essentially the same plug that on the fuel injectors it’s just keyed differently. Hopefully I know something soon. It seems like I may have to buy a decent quantity to get them so I’ll have some available to sell if I can get my hands on them

[K447]

- a simple Arduino module in between the sensor and the touch screen -

The signal between the dash and fuel level sender is analog and fairly low level voltage/current.

The module would need to be waterproof and robust mechanically.

Power needs to come from somewhere, and be switched with engine on/off.

[Turbo831]

If it was me I'd just extend the wire to speaker and put in a marine rated toggle switch, when alarm starts going off, toggle off beeper until you gas up again. Not foolproof since you'd have to remember to switch back on but better than listening to it go off.

[musubi]

If it was me I'd just extend the wire to speaker and put in a marine rated toggle switch, when alarm starts going off, toggle off beeper until you gas up again. Not foolproof since you'd have to remember to switch back on but better than listening to it go off.

I like this idea better. I put hydroturf over mine, which quieted it down, but too much I think. I can barely hear it when running about making it inaudible. I think I'll just wire up a switch for this.

[Hozzie]

If it was me I'd just extend the wire to speaker and put in a marine rated toggle switch, when alarm starts going off, toggle off beeper until you gas up again. Not foolproof since you'd have to remember to switch back on but better than listening to it go off.

Good idea. I may do this as well.

Also, see you are from Shelbyville. My family had a houseboat at Lithia for many years. Lots of good times on that lake.

[Mr. GP1800]

I started poking around my new 2023 FX svho limited that I picked up yesterday. I’ll have some more data tomorrow but so far it seems to be a gauge calibration issue.

I was able to match up fuel sender resistance values with the gauge reading. Tomorrow I will be matching up actual gallons of fuel in the tank with those sender output values. From there we will have the info to figure out the calibration and hopefully come up with a way to trick the gauge into reading correctly.

The solution to this may exist in the automotive world. There are converters out there that make any fuel sender work with any gauge. I’ll be doing some more experimenting in the next few weeks. This will get figured out for those who are interested in fixing the issue themselves

Im my opinion this is really the only issue holding the FX back from being the nearly perfect ski.

[Mr. GP1800]

In doing more testing with the fuel tank, gauge and fuel sender, I have discovered a HUGE issue. Yamaha says this is an 18.5 gallon fuel tank. My 2017 GP has an 18.5 gallon fuel tank and I can put at least 18 gallons in it. I could only get 16 gallons in my NEW FX fuel tank. And it took some effort to get that much fuel in it.

To do the testing I have done I powered up the fuel pump and pumped the tank dry. I had enough fuel in the tank to make the fuel sender move its first increment from a 130 ohm reading, which is the lowest the sender will read. It makes an immediate jump from 130 ohms to around 93 ohms at what happened to be 3.5 gallons in the tank. I pumped the fuel out into a measured fuel can. On my ski, the fuel beeper comes on when the gauge shows 10% fuel remaining, which is around 4 gallons. I then proceeded to add one gallon at a time seeing what the gauge read and what resistance the fuel sender showed for an ohm reading. Based off all of my measurements, the gauge should work as it’s supposed to.

The thing Im most upset about is I COULD ONLY GET 16 GALLONS IN THE TANK!!!!!!!!!!!!!!!

Thats probably a lot of the reason people feel the warning is coming on early. Because the tank holds less fuel than you were led to believe.

I did all of these same measurements on my 2017 GP so I’m pretty sure my accuracy isn’t an issue. I used the same measured container. But I find it very disappointing that I basically have 12 gallons of usable fuel capacity after spending well over 20k on a new ski.

Stay tuned. I will keep working on this issue until we have it solved

[K447]

Fuel Capacity (gal) 18.5 GAL

F4P-U7711-00-00 TANK, FUEL part number

From YamahaPartsHouse online parts diagrams
2021 FX CRUISER HO (FB1800AW) - Fuel Tank
2021 FX CRUISER SVHO (FC1800AW) - Fuel Tank
2021 FX HO (FB1800W) - Fuel Tank
2021 FX LIMITED SVHO (FC1800BW) - Fuel Tank
2021 FX SVHO (FC1800W) - Fuel Tank
2021 GP1800R HO (GP1800BW) - Fuel Tank
2021 GP1800R SVHO (GP1800AW) - Fuel Tank
2021 GP1800R SVHO WITH AU (GP1800CW) - Fuel Tank
2021 HO WITH AUDIO (GP1800DW) - Fuel Tank
2021 VX (VX1050FW) - Fuel Tank
2021 VX CRUISER WITH AUDI (VX1050BW) - Fuel Tank
2021 VX CRUISER WITH AUDI (VX1050CW) - Fuel Tank
2021 VX CRUISER WITH AUDI (VX1800BW) - Fuel Tank
2021 VX CRUISER WITH AUDI (VX1800CW) - Fuel Tank
2021 VX DELUXE WITH AUDIO (VX1050DW) - Fuel Tank
2021 VX DELUXE WITH AUDIO (VX1050EW) - Fuel Tank
2021 VX LIMITED (VX1050AW) - Fuel Tank
2021 VX LIMITED HO (VX1800AW) - Fuel Tank
2021 VX-C (VX1050GW) - Fuel Tank
2022 FX CRUISER HO WITH A (FX1800FX) - Fuel Tank
2022 FX CRUISER HO WITH A (FX1800GX) - Fuel Tank
2022 FX CRUISER SVHO WAUD (FX1800BX) - Fuel Tank
2022 FX CRUISER SVHO WAUD (FX1800CX) - Fuel Tank
2022 FX HO WITH AUDIO_FX (FX1800HX) - Fuel Tank
2022 FX HO WITH AUDIO_FX (FX1800JX) - Fuel Tank
2022 FX LIMITED SVHO (FX1800AX) - Fuel Tank
2022 FX SVHO WITH AUDIO_F (FX1800DX) - Fuel Tank
2022 FX SVHO WITH AUDIO_F (FX1800EX) - Fuel Tank
2022 GP1800R HO_HO WITH A (GP1800BX) - Fuel Tank
2022 GP1800R HO_HO WITH A (GP1800DX) - Fuel Tank
2022 GP1800R SVHO_SVHO WI (GP1800AX) - Fuel Tank
2022 GP1800R SVHO_SVHO WI (GP1800CX) - Fuel Tank
2022 VX CRUISER WITH AUDI (VX1050BX) - Fuel Tank
2022 VX CRUISER WITH AUDI (VX1050CX) - Fuel Tank
2022 VX CRUISER WITH AUDI (VX1800BX) - Fuel Tank
2022 VX CRUISER WITH AUDI (VX1800CX) - Fuel Tank
2022 VX DELUXE WITH AUDIO (VX1050DX) - Fuel Tank
2022 VX DELUXE WITH AUDIO (VX1050EX) - Fuel Tank
2022 VX LIMITED (VX1050AX) - Fuel Tank
2022 VX LIMITED HO (VX1800AX) - Fuel Tank
2022 VX-C (VX1050G-X) - Fuel Tank
2022 VXVX1050FW VX (VX1050FX) - Fuel Tank
2023 CRUISER HO WITH AUDI (FX1800FY) - Fuel Tank
2023 CRUISER SVHO WAUDIO (FX1800BY) - Fuel Tank
2023 FX HO WITH AUDIO_FX (FX1800HY) - Fuel Tank
2023 FX HO WITH AUDIO_FX (FX1800JY) - Fuel Tank
2023 FX LIMITED SVHO (FX1800AY) - Fuel Tank
2023 GP1800R HO_HO WITH A (GP1800BY) - Fuel Tank
2023 GP1800R HO_HO WITH A (GP1800DY) - Fuel Tank
2023 GP1800R SVHO_SVHO WI (GP1800AY) - Fuel Tank
2023 GP1800R SVHO_SVHO WI (GP1800CY) - Fuel Tank
2023 SVHO WITH AUDIO (FX1800DY) - Fuel Tank
2023 VX (VX1050FY) - Fuel Tank
2023 VX CRUISER WITH AUDI (VX1050BY) - Fuel Tank
2023 VX CRUISER WITH AUDI (VX1050CY) - Fuel Tank
2023 VX CRUISER WITH AUDI (VX1800BY) - Fuel Tank
2023 VX CRUISER WITH AUDI (VX1800CY) - Fuel Tank
2023 VX DELUXE WITH AUDIO (VX1050DY) - Fuel Tank
2023 VX DELUXE WITH AUDIO (VX1050EY) - Fuel Tank
2023 VX LIMITED (VX1050AY) - Fuel Tank
2023 VX LIMITED HO (VX1800AY) - Fuel Tank
2023 VX-C (VX1050GY) - Fuel Tank

[K447]

The above fuel capacity measurements for the 2023 FX Limited need to be corroborated, but if accurate, all the 2021 onwards models that use the same fuel tank may have substantially less usable fuel range than expected.

Current investigative data says:
16 gallons from absolute top full down to when the fuel pump is sucking air (with hull stationary on a cart)
Low fuel buzzer occurring when about 13 gallons have been consumed
Two more gallons consumed beyond initial Low Fuel warning and the fuel pump seems at risk of ventilation when riding due to fuel slosh and hull angles

Hence the 15 gallons usable estimate.

For reference the prior version GP1800 (2017 era) uses fuel tank part number F2S-U7711-02-00

At this moment it seems that the Yamaha 18.5 US gallon specification/claim for the 2023 FX fuel tank capacity is somewhere between misunderstood and misleading. It seems that from filled to the brim down to fuel pump drawing air is about 16 US gallons of fuel available to the engine.

If the Yamaha 18.5 number is the internal air volume of an empty and dry fuel tank, that can be misleading for a rider. Moreso when considering the fuel tank slosh factor when actually riding. Even on smooth water with careful rider inputs one does not want to be 'running on fumes' into the last couple of gallons.

[Mr. GP1800]

Here is the tank with 16 gallons added. You can see the fuel level is at least halfway up the diameter of the fill hose
Looking back at the fuel tank from the front of the engine the fuel is touching the top of the fuel tank.

[TXDroneRacer]

Here is the tank with 16 gallons added. You can see the fuel level is at least halfway up the diameter of the fill hose
Looking back at the fuel tank from the front of the engine the fuel is touching the top of the fuel tank.

Both of my 23's tanks look just like that. I filled both of them up slowly giving time for the air to come out. I agree with you... Only going to get 15 to 16 gallons of fuel in these tanks.

[Wild Thing]

Guys you do need a bit of space for expansion as a safety margin, you only have to open the tank on a warm day or after a road trip ant the cap will near blow out of your hand on the last threads. Clever marketing and it probably is an 18,5 gallon tank in volume

[Mr. GP1800]

Guys you do need a bit of space for expansion as a safety margin, you only have to open the tank on a warm day or after a road trip ant the cap will near blow out of your hand on the last threads. Clever marketing and it probably is an 18,5 gallon tank in volume

My 2017 GP is listed as an 18.5 gallon tank. I can put at least 18 gallons in it. I may have even gotten close to 19. When they redesigned this fuel tank it got smaller. There’s no way around that. To only be able to put 16 gallons in a big ski like this is sea doo type crap. I’m very disappointed.

[K447]

… space for expansion … on a warm day … the cap will near blow out of your hand on the last threads. …

The consumable fuel tank capacity on our prior generation Yamaha (2017 GP1800 for myself) is around 18 gallons, perhaps 19US gallons if stuffed to the brim. We have never ridden our GP1800 tank down to ‘engine sputters’ but I have refueled almost that much after an exhaustive ride.

The 2021-2023 model year fuel tanks in the FX (and also GP1800R, VX series) are empirically smaller, containing about 16US gallons of consumable fuel volume when filled ‘to the brim’.

This is exacerbated by the low slope of the fuel fill tube which slows the rate fuel can be poured into the fuel filler mouth. Complaints about fuel burping back out during rapid refueling date back to the 2021 FX model introduction IIRC.

The expansion space air volume is molded into the top of the 2021+ fuel tank, visible in this photo.

Here is what a prior Gen fuel tank looks like (GP1800)

The small black nipple is where the air vent line for the fuel tank attaches. It vents through a liquid catch bottle and then to atmosphere through a vent on the hull exterior.

The difference between 16 gallons and 19 gallons (at maximum tank stuffing) is almost 20 percent. But that is sucking the tank dry. Setting aside the bottom two gallons as a safety margin to avoid the fuel pump aerating during fuel slosh, the comparable numbers are 17 usable versus 14 usable. That ‘missing’ three gallons can really matter, especially when riding far from shore or longer distances between available refueling locations.

At the moment it seems that when a new FX would literally run out of fuel the prior generation tank would have two to three gallons remaining in the tank (other factors being equal).

[JetWaterRunnerFellar]

My 2017 GP is listed as an 18.5 gallon tank. I can put at least 18 gallons in it. I may have even gotten close to 19. When they redesigned this fuel tank it got smaller. There's no way around that. To only be able to put 16 gallons in a big ski like this is sea doo type crap. I'm very disappointed.

This is really frustrating. Have a newer GP and just bought an FX SVHO. Only 16 gallons?!?! Possibly less? Thought advertising 18.5? Didn’t Yamaha get into trouble fudging horsepower numbers a while back?