Well, hey what do you know.
I ran around today untill I ran out of gas and needed the reserve.
Starting from a full tank (on the side stand). I ran for 120 miles at that time there were two bars showing on the gauge. This is where I would always fill up in the past.
I kept going untill 160 miles and I get one bar on the gauge and a flashing fuel pump thing.
At 165 miles it dies and I needed to switch to reserve. Drove around for another five miles to find a station.
Took on 3.7 gallons of gas (on the side stand).
So, the gauge does work and work right sort of. Its a five miles until the engine dies and I need the reserve gauge.
I cant really account for the first time I ran out of gas and it showed two bars. I dont care that was a long time ago.