MFG Gauge lost fuel tank calibration

[theclamman]

Has anyone had their MFG gauge lose it's fuel tank calibration over the winter layup? The batteries were disconnect for about 5 months during storage.

I believe it's a calibration issue. At rest the gauge reads empty, and I know the boat has roughly half a tank in it. When I go up on plane the gauge will read, and shows about 50% less fuel than I should have as the boats incline changes.

I've had the gauge system for 3 years now, and this is the first time it has lost the fuel tank calibration.

[Moonlighter]

I would first be looking at the tank sender.

[theclamman]

The tank is only 3 years old and came with a new sender. I did the standard tapping, and sloshing the gas around to make sure it wasn't stuck.

I'll take a closer look at the wiring next. I spoke to my Suzuki dealer yesterday and he said they've seen this a handful of times, generally resolved by re-calibrating.

Also discussed that this is the 2nd year in a row the MFG has lost settings over the winter, last year it defaulted back to the water speed setting(Moonlighter pointed me in the right direction then). My dealer said if it continues to lose settings they would replace the gauge.

[theclamman]

I spent the weekend doing a lot of troubleshooting, testing the sender, testing the wiring, and pumping the tank out completely to know exactly how much gas was in it. Some how the MFG gauge calibration was in fact off.. The ohms reported by the sender were reflecting about 4/10ths of a tank, and the gauge was showing 3/4 of a tank. I re-calibrated the gauge and now the gauge is showing the correct fuel level. I'll keep an eye on it and see if it loses it again.