My odometer packed up a few months ago and I am waiting for bad weather so I can justify down time on the bike to dismantle it.

For those in the UK, it is still 30 degrees plus here in Western Australia. Sorry, I had to chuck that in, my Dad lives in Sussex and has not stopped whining about the weather!

Anyway my fuel indicator lights were not working when I purchased the bike years ago and I have not worried, I just check the speedo and fill up at 300.

Those astute members will have worked out my predicament by now.

Anything obvious with the lights (except the bulbs) I should be looking for?

I await thoughts as to this too.
Have learned not to trust the fuel gauge.
It seems to give a just very general indication of fuel level.
I believe that the sending unit arm needs a little tweaking (other posts).
Watch more closely the odometer mileage now.
Have kind of cut it close several times.
One time had to push it alongside a very busy 4 lane road, in the grass....and that was a challenge...(was cussing),
You think they are heavy to pick up?
Try pushing one through tall grass ...and not turning it over.
My limited experience with my bike is that when they run out of fuel, it happens pretty quickly and there is not a lot left in them after the first sputter.

...and realize Bigsax that previous post did not address the fuel warning light.
I don't know anything about that because have not ever seen mine light up. ...though have run it out of gas

The only reliable gauge I have ever had was to open the tank and have a look and use the odo as a rough guide or as someone else here said use the digital gauge you get at birth, stick one of your digits in the hole at the top. Its a bit like being a McDonald and never trusting a Campbell.