Fuel sender calibration

[Delp]

Hi I have a Jap soarer with the tube type fuel sender unit. It's been inaccurate with wrong readings fluctuating. I have cleaned the unit with methylated spirit still no good. Does anyone know how to calibrate these blue trim pots. I know that they are calibrate from factory.
Any information or advice be much appreciated

 

[ivan129]

If you can find the wiring diagram for the fuel sender / gauge wiring, you should be able to identify the pins on the white connector. Most likely it will be powered and have outputs that run off to you fuel gauge. Once you have identified the pin/s that provide the fuel level signal to the gauge, you should be able to trace the circuit of the sender and determine which pot/s to tweak. It looks like the chip also has markings on it, so a google search might help to track down the device helping you to trace and draw the schematic. One thing to keep in mind... electronic fuel gauges often have dampening so tweaking one of those pots might take a second or two to make a change at the gauge.
Worst case. trial and error.
Good luck.