Check the Fuse: Look at your bike’s fuse box. A blown fuse for the instrument cluster is the easiest and cheapest fix.
The "Shake" Test: Sometimes a float is just stuck. With the engine off, gently rock the bike side-to-side to see if the movement frees it up.
Inspect the Wiring: Check the wires coming out of the bottom or side of your fuel tank. If they are loose or corroded, the signal won't reach the dash.
The "Stuck" Float: Sometimes the metal arm gets bent or caught on the side of the tank, preventing it from moving.
Tank Shape: Most motorcycle tanks are wider at the top and narrow at the bottom. This is why the first half of the tank seems to last forever, while the second half "disappears" in minutes.
Corroded Contacts: Since the sender unit is sitting in fuel and exposed to moisture, the electrical contacts can get "gunked up," leading to jumpy or dead readings.
The Sender Unit (Inside the Tank): This is a small float (usually plastic or foam) attached to a metal arm.As the fuel level changes, the float moves up or down.
The Potentiometer (Variable Resistor): The metal arm is connected to a resistor.When the float moves, it slides a contact across this resistor, changing the amount of electrical current sent to your dashboard.
The Indicator (On the Dash): Your dashboard reads that electrical signal and translates it into a needle movement (analog) or bars (digital).