Bouncing fuel needle

[DimitriT]

This is on the 82 gs550l. Bike runs great but when I run it for more than an hour or so and at highway speed the fuel level indicator goes nuts. It bounces, waves around, pegs up or down. If I shut it down and let things cool down it works normally again.

Help appreciated.

[Grimly]

I believe there's a fuel gauge electrical stabiliser in the circuit to the gauge. Just a resistor, basically.
When resistors get old they can vary hugely in value or even go intermittent, often showing their change in characteristics when hot.
This is just a general observation from what I've seen on other bikes, etc. It might be there's nothing like that in your circuit, but generally undamped gauges bounce around a lot.

[DimitriT]

Thanks for the reply. I'll see if I can take it apart and identify what they have in there.