Quote Originally Posted by Scotty
You could drain the tank and remove the float and sender assembly, plug it back into the harness and test it that way, once it's out you can put a multimeter on the terminals and see if it's behaving. A fuel gauge isn't a must-have - does it have a reserve tap as well? If not, fill it up, strap a full 5 litre fuel can on the pillion seat, zero the trip meter and ride it until it runs out - then you know how far it'll go on a tankful and be mindful to fill up before it gets that far in the future - no worries... 8-)
open the cap and look lol