That sounds like the wiring for your sender unit on the tank has somehow come off or otherwise failed; or the sender unit itself has fallen apart inside the tank; altho I guess it could also be just the gauge that spat the dummy. :shocked:
One way to check/confirm if it's a failed sender unit or dud wiring is to pop the dash open & disconnect both of the analogue gauges - fuel AND temperature. Label or otherwise identify the wires & secure them out of the way, then put the dash back on properly & start your Spyder up, maybe even take the opportunity to go for a ryde around the block. If the digital gauge displays for both fuel level & coolant temp work OK, then it can't be the sender or its wiring. But if you have exactly the same problem with the digital gauge, ie it shows empty when it's full & displays the warnings, then it's most likely going to be the message from the sender unit either not being there at all due to a wiring problem or the sender has failed or fallen apart inside the tank! Your first step then should be to check that the sender unit is still plugged in to the wiring loom with wires that aren't shorted or otherwise compromised.... & that might need you to remove a bit of tupperware! If it's not that, then you may be faced with having to remove the sender from the tank & either fixing or replacing it! :sour:
If the wiring is good & it's all connected & working properly, so you get to the 'pulling the sender out of the tank' stage, don't get suckered in by everything looking fine at first glance - you really need to check it all carefully! A tiny worn spot in the 'quadrant' used to show the level can make the float stick or not read properly, altho sometimes this sort of failure can also be attributed to a float that no longer floats (ie, it's got a hole in it so now it sinks instead of floating to give you a level) but I'm not sure that Spyder sender unit even uses a quadrant or a float to determine the fuel level, those 'old school' devices are becoming less prevalent these days! Anyhow, good luck getting it sorted whatever the problem may be. I hope this helped some! :thumbup: