When I fill the fuel tank to the brim, the gauge shows full, but after about 20 miles of riding the needle gradually falls a bit, fluctuates up and down for a while, then gradually drops to empty until the next time I fill the tank, when the same things repeats.
I removed the sensor unit from the top of the fuel tank, cleaned it with WD40, (it did look pristine with no wear or dirt present), and checked its operation while out of the tank.
It work exactly as it should; when I moved the float, the fuel gauge needle on the dashboard responded straight away, both at maximum and minimum levels, and in between.
However, as soon as I put it back in the tank, the gauge fell to ‘Empty’. The float does not have any holes in it, and I can see when I immerse it into the petrol, the float comes up as it should. The float and connecting rod are not catching anywhere inside the fuel tank. There are no shorts on the wiring, (I checked with a multimeter)
When placed back in the tank it just falls to empty. Everything looks fine and there is obviously no break in the wiring, so what may be the problem?
I have located a fully working fuel sensor from a Kymco Agility 125, which to my eyes looks identical. Might fuel sensors be interchangeable between different models of scooter? The locking plate to secure it to the fuel tank is identical.
Any thoughts greatfully received, on a solution to the problem or whether the Agility fuel sensor will work in my Miler..