Fuel Gage Sender 101

I'm thinking of buying a Lowrance LMF-200 multi sensor. It tells me fuel level, fuel flow, speed, MPG, etc, etc. I'm not sure what gage I want to replace, though, but replacing the fuel gage makes the most sense. If I do replace the fuel gage with this multi-sensor piece of technology, how will I know the sender will give me accurate fuel level readings on the new gage? Are fuel tank senders pretty much standard and how do they work? Is it a variable resistance (low resistance when tank is low)? Will I be able to calibrate the new fuel gage to my tank/sensor combination?

1997 Chaparral 2335 with 75 gal tank

Re: Fuel Gage Sender 101

On boats sold in the US, stock senders are typically 230 ohms at empty, 30 ohms at full. Assuming the Lowrance unit follows this convention, expect the same accuracy as with your current gauge.

Re: Fuel Gage Sender 101

A better solution than using inaccurate fuel "level" sensors is to use a true fuel flow monitor like the Navman 2100/Northstar 210. You fill the tank, tell the unit how much fuel you have and go. The transducer sits in the fuel line and gives you 15 second updates on fuel flow (gallons/hour), fuel remaining, total fuel burned over time, and total fuel burned for the trip. Just like the fuel computer in your car. Removing a fuel gauge to replace it with another gauge that relies on the existing fuel sensor is a waste in my view. Although I kept my fuel gauge, I added a Navman 2100 because the gauge danced all over and was very sensitive to boat attitude so one never knew how much fuel was really in the tank.