MRWood
Well-Known Member
Last winter while redoing my boat, pod etc, I also changed fuel tank and gauges. My fuel gauge reading is not matching what is in the tank. It’s been a bit of a head scratcher for me this summer as I took a while to realize it was off. Fuel shows up as a percentage of full on my Mercury smartcraft gauge. As an example when I would go and fill the tank the gauge could say 65% full but the actual fuel added would total up to an amount greater than the 35% required to fill the tank. The gauge should have been reading more like 47% full.
After doing this a number of times this summer I thought the sender must be wonky. It is a Moeller fuel sender with float on end of metal rod. Then after more thought I came to the realization that my irregular tank shape is the cause of the issue. The bottom portion is shaped to the hulls V. Therefore the lower section of the tank holds less fuel per inch of height than the upper section.
Yesterday I went out and measured how many inches of fuel was in the tank. It was 9” which is about 52% full, if my math is correct, while gauge showed 68% full. The issue is that the sender thinks that there is twice as much fuel in the triangular bottom than there actually is. (See my pic of drawing and notes). Today I bent the sender arm up somewhat and now fuel % is at 60%, which is getting closer to the actual of 52%. This will also help me if I was to get near empty as the float will sit a bit higher when the reading shows empty.
Are there fuel senders that can be calibrated to take irregular tank shapes into account?
Have any of you had this issue and were able to rectify it?
I guess it doesn’t need to be perfect but close is best.
After doing this a number of times this summer I thought the sender must be wonky. It is a Moeller fuel sender with float on end of metal rod. Then after more thought I came to the realization that my irregular tank shape is the cause of the issue. The bottom portion is shaped to the hulls V. Therefore the lower section of the tank holds less fuel per inch of height than the upper section.
Yesterday I went out and measured how many inches of fuel was in the tank. It was 9” which is about 52% full, if my math is correct, while gauge showed 68% full. The issue is that the sender thinks that there is twice as much fuel in the triangular bottom than there actually is. (See my pic of drawing and notes). Today I bent the sender arm up somewhat and now fuel % is at 60%, which is getting closer to the actual of 52%. This will also help me if I was to get near empty as the float will sit a bit higher when the reading shows empty.
Are there fuel senders that can be calibrated to take irregular tank shapes into account?
Have any of you had this issue and were able to rectify it?
I guess it doesn’t need to be perfect but close is best.
.
