[avigil]

The remainder of fuel from when the fuel light comes on is in the lines and still in the tank - about 5 litres still in the tank

Also, I've noticed that often the fuel indicator will come on for a few miles then go off for awhile then come on again, etc. I'm assuming it's because of different angle, etc that the reading changes. As Dingo said, you have quite a bit of fuel when the light comes on. If I remember, it's roughly 1.3 gallons. So, you can still go quite a few miles/kilos without risk of running out.

That being said, I fill up often when it's convenient and haven't ridden more than 15 miles after the light has come on.