when you say fill it up does that mean the gauge is reading full or literally no more fuel can be added?
I suspect that the fuel gauge is reading more accurately with less fuel. I had the light come on the other day and only added 2 gallons. Drove a few miles then added 15 gallons. the gauge read nearly full but dropped quickly to about half and stayed there for quite a while.
With the light on at 2-3 gallons + 12 gallons should be around 15 or 3/4 but if the gauge starts to read a bit higher, then maybe that's why you think you are getting to capacity.
my boat used to be like this.
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