YAMAHA FUEL GAUGE DOESN'T READ ACCURATELY

[AQUADJ]

I have twin 1998 250hp OX66 fuel injected motors with Yamaha gauges. My gauges do not read fuel consumption below 10 kts., so while trolling my burn is inaccurate. Is there an adjustment on the fuel gauge other than the 1-3% adjustment, or should I be looking at the relay, lines, or something else?

[rodbolt]

are we talking about fuel tank level gauges or the fuel management gauge ?

[AQUADJ]

Sorry...fuel management gauge.

[rodbolt]

look at the flow senders and see if they are mounted correctly and if they have 3 or 4 screws on the bottom.

[AQUADJ]

There are 4 screws and the unit is positioned so the screws are facing downward toward the deck (screw heads face deck). It's approximately 10 degrees off level toward the output side.

[rodbolt]

they are the latest versions, it should read fuel flow on either engine or both,depending on mode selected, look in the 04 marine tech guide or the rigging guide.both have all the settings for calibration.
the book says mount them level, but I cant see 10* making much difference.