2024 721 - gas guage not working

[WVTundra]

Anything I should try to do to get the gas guage working before I call the shop? I filled it up, fished a tournament, next day I took all the batteries out and added a new electronics battery, hooked everything up, everything worked, took boat out next trip gas guage not working. Did some changing out units, checked and gas guage working, next day on the lake gas guage not working and not worked sense. Is there a fuse for the guage or float? Could the float be stuck? Or just not working right? Anyone else have this issue.. ?

[Hyco Bass]

I had same issue after installing new lithium house battery. Will try to link thread here......https://www.bbcboards.net/showthread...2#post13913552

Hope this helps

[Meleagris1]

If you have a Mercury I would pull the multi gauge and install the Mercury smartcraft gauge - that's all I use to monitor fuel. Its extremely accurate.

[WVTundra]

I have a mercury smart guage also, just like stuff to work on a new boat.. sorry it’s my ocd getting me ..

I did put a jumper from neg to neg and that worked. But I am going to start using the smart craft to monitor fuel consumption

[kwilliams325]

Mine did not work properly until a few months ago...and it is a 2021

[ifishinxs]

Pretty easy to pull the carpeted cover off and check the gauge..The L shape tank doest make for the best accuracy with a float sending unit.

[TX721]

Pretty easy to pull the carpeted cover off and check the gauge..The L shape tank doest make for the best accuracy with a float sending unit.

Merc Smart guage!

[ifishinxs]

Merc Smart guage!

You still have a sending unit to the gauge. The float sending units do fail or get stuck. I have changed a few over the years.

A Mercury Smart Craftfuel sending unit, also known as a fuel sender, is a device that provides fuel level data to the SmartCraft digital gauges. It works by measuring the resistance of a float-based fuel level sensorand transmitting this information to the gauge. This allows for accurate fuel level monitoring and consumption tracking on boats with SmartCraft systems.

[davidsa]

I have a mercury smart guage also, just like stuff to work on a new boat.. sorry it’s my ocd getting me ..

I did put a jumper from neg to neg and that worked. But I am going to start using the smart craft to monitor fuel consumption

I use both on my boat and I actually see value in both. Call me crazy, but on my 2014 I felt the smart craft always had me within a gallon of how much I put in at fill up. I'm not seeing that level of accuracy on my 2024. Kinda reminds me how some of my vehicles reported mileage is almost exactly what the manual calculation says; and others are off by 1mpg on nearly a full tank.

[alli ss]

Can somebody post a pic of the screw locations on the lid that covers the fuel tank?

[Mahomee]

You still have a sending unit to the gauge. The float sending units do fail or get stuck. I have changed a few over the years.

A Mercury Smart Craftfuel sending unit, also known as a fuel sender, is a device that provides fuel level data to the SmartCraft digital gauges. It works by measuring the resistance of a float-based fuel level sensorand transmitting this information to the gauge. This allows for accurate fuel level monitoring and consumption tracking on boats with SmartCraft systems.

Smart craft does not use the factory sender or any sender. It measures how much fuel you use thru the fuel FLOW into the actual engine.

[alli ss]

Smart craft does not use the factory sender or any sender. It measures how much fuel you use thru the fuel FLOW into the actual engine.

My smartcraft system uses the fuel level sender.

[Mr Phoenix55]

Needs to be connected to starting battery
improperly grounded where it’s connected presently

[XRD]

Can somebody post a pic of the screw locations on the lid that covers the fuel tank?

My 721 had 8 screws. 4 on the aft, open the rear storage and livewells and feel for them. On the 4 in front, a couple were behind the seat backs, so the seats had to be removed, then feel for those also.

[ifishinxs]

I use both on my boat and I actually see value in both. Call me crazy, but on my 2014 I felt the smart craft always had me within a gallon of how much I put in at fill up. I'm not seeing that level of accuracy on my 2024. Kinda reminds me how some of my vehicles reported mileage is almost exactly what the manual calculation says; and others are off by 1mpg on nearly a full tank.

Same! New Vessel view mobil and the mechanical gauge. I like redundancy on my fuel use.