Gas Level Gauge - less active

Flyindutchman · **Posted:** Sun Feb 22, 2015 12:41 pm

Any suggestions as to what happens to the fuel level gauge to make it stop functioning accurately? Is there a simple fix?

I just noticed last season that it was starting to only show a level when the tank was over 1/2 full but otherwise just read E?

Obie · **Posted:** Sun Feb 22, 2015 2:20 pm

The sender unit inside the fuel tank is likely at fault or you have a bad electrical connection. I would start at the fuel gauge and check connections first because it is easier. To replace the sender unit you need to open the port on the fuel tank. This is a job for a mechanic unless you know exactly what you are doing and fully understand the risks of working with gasoline vapors.

Flyindutchman · **Posted:** Sun Feb 22, 2015 2:40 pm

Obie wrote:

The sender unit inside the fuel tank is likely at fault or you have a bad electrical connection. I would start at the fuel gauge and check connections first because it is easier. To replace the sender unit you need to open the port on the fuel tank. This is a job for a mechanic unless you know exactly what you are doing and fully understand the risks of working with gasoline vapors.

So...no taking a peek in the fuel tank with a Zippo for light then? Lol.

No - I would have someone qualified do that for sure. Is it a common issue? I recall numerous boats I've driven in the past having dead fuel gauges too?

Thanks.

LouC · **Posted:** Sun Feb 22, 2015 3:28 pm

You can make sure that the connections on the back of the gauge are tight, and you can do the same for the connections on the sending unit (usually under the gas tank hatch or a circular deck plate if there is no hatch for the tank).The sending unit is usually under the rear seat area.
They are not hard to change but obviously you need to be careful with gas fumes.
I always shut off the battery switch when doing jobs like that.

TX H210SS · **Joined:** Thu May 27, 2010 9:10 am **Posts:** 1488

Mine doesn't hit E immediately when it gets to half, but you can damn sure watch it moving that way. It will stay on full a long time, then once it starts downward it makes up for lost time.

Maybe I have same issue but always thought the floating sending unit was ineffective in a rocking boat. Several have gone with fuel flow meter.

babbot1 · **Joined:** Tue Mar 12, 2013 3:46 pm **Posts:** 570

Gas gauges are so inaccurate in boats I am surprised they even use them or haven't come up with the tractor style gauge right on top of the fuel tank.
By all means get it fixed but I've learned to use my hour meter along with the gas gauge to estimate usage. When trailoring I filled up before every run and watched the clock. Now being slipped I go so many hours and fill up if the gauge is close to 1/2 which really means only 1/4 tank left. If we are going on a long run I will fill up regardless. I have found 10 hours is roughly 1/2 a tank in mixed usage.

Paul I. · **Posted:** Tue Feb 24, 2015 1:16 pm

"Gas gauges are so inaccurate in boats I am surprised they even use them" Well, for me that statement is not that far off. You need to know your boat! I use a flow meter too. So between the GPH and the fuel gauge, I have a better idea of how much I have left in the tank.

LouC · **Posted:** Tue Feb 24, 2015 4:11 pm

Actually when the boat is floating level they are not that inaccurate. Think about it, the tank is long and narrow and the trim changes a lot on boats in use. At the gas dock if mine says 1/2 it takes about 20 gallons to fill it. That's just about right. So I check it when I head out before running on plane.

278TheNiseeII · **Posted:** Wed Mar 04, 2015 2:52 pm

The answer to the original question is probably the sending unit in the tank.
If it always works above 1/2 tank and just drops to zero below.
The gauge works with a moving arm and resistive contact system (potentiometer).
The contacts below 1/2 tank are either fowled due to contamination or the wire is broken below 1/2 tank.
Either way, it is an easy fix to buy a new sending unit and install.

ric · **Posted:** Wed Mar 04, 2015 8:25 pm

Sending unit going bad is common. Get a reed switch type and never worry about it again.

Flyindutchman · **Posted:** Wed Mar 04, 2015 8:45 pm

278TheNiseeII wrote:

The answer to the original question is probably the sending unit in the tank.
If it always works above 1/2 tank and just drops to zero below.
The gauge works with a moving arm and resistive contact system (potentiometer).
The contacts below 1/2 tank are either fowled due to contamination or the wire is broken below 1/2 tank.
Either way, it is an easy fix to buy a new sending unit and install.

Thanks for this.

www.iFourWinns.com

Gas Level Gauge - less active

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