Yes, they need calibration. The Intellitronix gauge isn't a simple plug-and-play; it has to be calibrated to your specific tank's sending unit and fuel volume. Follow the calibration procedure in the instructions to set the empty and full points. If it's still off, your stock sending unit might be worn or the resistance is out of spec. Check its ohms when empty and full should be around 73-10 ohms for most Harley units. A bad ground to the sending unit can also cause wonky readings.

 

Yes, ....

Hey Bob-o. Did you lose a post earlier today? There is a mysterious post in a thread about wheels and axles where you posted something about vacuum and AFM/DOD. Maybe you were in some other 4 wheeler Forum. I don't think Harley is up to that point.

This is where it went. New rear rim question | V-Twin Forum

 

Ok Roberto, its been on the bike for a few yrs. Im assuming it was calibrated when installed. I didnt own the bike at that time. Ive never noticed until the last yr. or so as its run out of fuel while riding and the gauge showed alot more than what was in the tank. If i would have known I would have switched over to reserve or looked for a station and filled up. I thought the gauge was measuring accurately at the time. Could it need recalibration over time?

 

Yes, it absolutely can need recalibration over time. The float arm in the tank can wear or bend slightly, changing the reading. It's a common issue. You'll need to reset it by either running the tank completely empty and then filling it to full, or by adjusting the sensor itself if your model allows it. Check your owner's manual for the specific recalibration procedure.

 

If you zoom in you can see the fuel gauge Im referring to.

 

Ok, thanks for your advice on the problem Roberto, much appreciated.