1993 Crownline 225 CCR - Fuel Gauge Issues

[FuelishBehavior]

It seems that on my boat the fuel gauge, while on the water, typically always reads full. However, when on the trailer, by my distance calculations after I've filled up, it appears to read what I would assume to be the correct amount in the tank. Attitude wise, the bow of the boat seems to be pointed further down while on the trailer but when in the water the bow seems to be higher. Should I just replace the sending unit?

 

[Silvertip]

Re: 1993 Crownline 225 CCR - Fuel Gauge Issues

Think about it. The sending unit is a float mounted on the end of an arm. As the level in the tank changes the resistance of the sender changes and the gauge reacts accordingly. Pour a half cup of water. Now tilt the cup. If there was sender in that cup it would read differently when tilted that it does when level. The surface of the fuel (water in the cup) stays level but the sender is tilted so the relationship between the arm, the resistance element and the gauge reflect the change. So no -- a new sender would not change a thing. You don't have to worry about running out of gas on the trailer do you. Make your fuel gauge readings on the water, at the dock so the attitude of the boat is relatively consistent. Fill the boat on the way to the water. You then know how much fuel you have. You can adjust the the float arm for an accurate reading at Empty, 1/2 or Full but you cannot calibrate it for all three. You calibrate the arm for an empty reading. Why? Again -- you know when the boat is full since you filled it on the way. You want to know with "accuracy" when it is empty (or getting there) while you are on the water.

 

[Bondo]

Re: 1993 Crownline 225 CCR - Fuel Gauge Issues

It seems that on my boat the fuel gauge, while on the water, typically always reads full. However, when on the trailer, by my distance calculations after I've filled up, it appears to read what I would assume to be the correct amount in the tank. Attitude wise, the bow of the boat seems to be pointed further down while on the trailer but when in the water the bow seems to be higher. Should I just replace the sending unit?

Ayuh,... The results will be the same,.... Boat fuel gauge are notoriously Inaccurate...

 

[FuelishBehavior]

Re: 1993 Crownline 225 CCR - Fuel Gauge Issues

I agree completely with both of you. I was wondering whether or not just unscrewing the sending unit and rotating the arm, if it has the necessary room in the tank, about 180 degrees that way it's reading as accurate as possible on the water as opposed to on the trailer.

 

[Silvertip]

Re: 1993 Crownline 225 CCR - Fuel Gauge Issues

It would probably make the situation worse. For best accuracy and least amount of bounce, the float should be at the exact center (fore-aft and side-to-side but that's not possible in most applications.