Strange fuel issue

[Beebop]

This may be difficult for some as its in metric measurements.

I run an 06 XB9SX with 87000km.
Its been well maintained and runs beautifully.
The past 2 tanks however I have run out of fuel
before the low fuel light comes on, and it takes only 10,5L
to fill it up. The norm is when the light comes on, it takes
around 11L to fill up. Its just around 250km range that this happens.
I usually top it up after 3 round trips to work, but now I cant
do that as it "runs out" of fuel even though its not empty.
I understand the fuel capacity to be 14L and having owned
the bike for the past 57000km, I have put in 13L at times.

Any ideas or suggestions where to look ?
Thanks all.

[Tbone]

My Ulysses did this when the big o ring on FPR was blowing out slowly. I can only guess that it was passing fuel on the sensor and did not indicate a low fuel light until the tank was completely empty and I was stranded on the side of the road.

[Barrett]

Robin: Tbone spot-on. All your ailments are symptomatic of a failing fuel pump. False low fuel signal...failure of pump to pick up and pressurize low fuel quantity in frame...false "frame empty" symptom. If you're still in South Africa, good luck getting a complete OEM pump rebuild kit or new pump.

[Beebop]

Thanks Barrett. I had considered the fuel pump pressure. I did replace the fuel pump, regulator and filter less than a year ago on my wife's XB9, so the parts are available here (Bosch pump etc)
I took the complete pump assembly from her low mileage bike and put it in mine since mine is slightly newer and gets used daily. I would be surprised if it was faulty, but anything
is possible. I could quite easily swap them back to see if the problem moves. I did originally put hers into mine to prove the fault on my bike was the fpr, and it was easier to swap the entire assembly, and
then just replace hers while it was out.