Fuel Gauge Issue?

[CJM]

My starboard fuel gauge fluctuates when at cruise. While increasing the throttle, the gauge starts dropping dramatically. When I come back to idle, the gauge increases and shows the correct amount. My Port gauge is good. Note: the last few times that I filled up, both tanks needed almost the same amount.... Could it be the gauge or the sender?
(2000 Searay Sundancer 340 with twin 7.4 (380hp) Horizons)

 

[JVM225]

Sounds like the gauge is working. While notoriously inaccurate, they usually either work or they don’t.
Might be time for a new sender. Sounds like yours is moving around in there and giving you crazy readings.
You can start by checking the connections, but ultimately you might have to just replace the sender.

 

[scoflaw]

Think about the angle of the gas in your tank, accelerating verses slow cruising. Mine does the same when it gets below half and all my previous boats as well. Damn even my pickup does it

 

[Korkie]

Also, check your grounds. But sounds like sending unit to me as well.

 

[CJM]

Think about the angle of the gas in your tank, accelerating verses slow cruising. Mine does the same when it gets below half and all my previous boats as well. Damn even my pickup does it

My old boat used to do this as well (when the bow was rising, the gauge would drop), but that was a single screw with one tank... My current boat has twin engines with 2 tanks.. The port gauge is fine and only drops when fuel is being burnt...

 

[CJM]

Thanks for all the responses... I'll check all the grounds..