Been experimenting with a range of shunt resistors wired directly across the terminals of my 280mm fuel sender.

Athough my calculations, based on the data Charles kindly provided, suggested a higher value would better suit, settled on a 750 ohm one.

Have now run two full tankfuls in testing with this value. With a full tank (three shut-off clicks) I see 100% reading for 20 to 30 miles before reading begins to drop, with 210 - 230 miles of driving before 0% appears and stays there. At this point a refill takes a little over 30 litres.

As before the reading jumps up and down during driving, but although not optimal, I now find I have a usable gauge for a 200+ mile journey without spending miles driving with the gauge on 0%.

YMMV but imagine others could benefit from the quick and simple mod. BTW I used 0.5 watt resistors in testing as the current through sender circuit is minimal.

Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone