I have been having some issues with my new fuel and temperature gauges.
I wanted to check the calibration and ran the tank right down to zero and into the 5 litre reserve. At least I now know that when it starts bouncing on zero it is reasonably correct and I have about 5 litres left.
In part of my checking, pouring in 5 litres at a time and then checking the resistance to the sender in the fuel tank, I discovered that for the last 12 litres or so to a full tank (55 litres)there was no change in the reading.
This explains why the tank never reads full. In effect There is no change in the resistance from a fraction over 3/4 or about 7/8 to a full tank.
I don't know if this is because I have a faulty sensor or not but since it seems to be a common problem it may simply be that the sensor that Morgan uses is maxed out at 7/8s of a tank.