*THE HULL TRUTH is the world's largest FREE network for the discussion of Boating & Fishing. Whether you're researching a new boat, or are a seasoned Captain, you'll find The Hull Truth Boating & Fishing Message Forum contains a wealth of information from Boaters and Sportfishermen around the world.
Welcome to the updated THT!
If you are having trouble signing in, please email feedback@thehulltruth.com with your username and we will help you. We thank you for your patience as we help you access the new site!
Random Quote: If you can taste the salt in the air.....it's time for a bigger boat!
Ran out of gas friday.Fuel gauge showed >1/8 tank. When I switched the ignition to accessory (after chcking fuel lines and the rancor filter) the gauge needle registered a little less than 1/2 , then slowly fell to a bit over 1/8. Gauge was installed new last year (do not know brand as I'm not on the boat, $20.00 or so from West Marine ), also installed a brand new Moeller 52 gallon polyethylene below deck fuel tank while replacing deck. Does this sound like a gauge or a sending unit problem? Is there a way to test the gauge before going below deck and checking the sending unit and connections? Any help is greatly appreciated.
Remember gauges often read differently with boat at cruising attitude vs at rest. You might have the wrong length sender or poorly-adjusted float in that new tank.
Ancient mariner saying: 1/3 out, 1/3 back , 1/3 reserve.
Centroid Products makes a no moving parts capacitance-tube sender that has 2 external calibration screws so you can adjust gauge needle to read exact Full and user-preferred "Empty" (i.e. actual empty, usable-fuel empty or with any desired amount of safety reserve left in case you have a bad habit of tempting fate on fumes.
I would assume the sender was installed incorrectly. since you now know your boat is out of gas for sure, it would be easier to install the sender, and make sure that when it is at the bottom of its swing, it is going to the bottom of the tank. i bet that it is hitting the bottom of the tank before it reaches the bottom of its stroke, therefore needed the arm to be shortened a bit.
__________________ Aristocraft boats. building quality boats since 1946.
Stamas Tarpon 290 Yanmar 6lp
I have owned and operated many boats in my time,,, NOT ONE OF THEM have EVER had a fuel tank sender / Gage that worked longer than 1 or 2 weeks. They are absolutely useless!!
You have 2 choices, one costly, one costs nothing:
1. Install an in-line a Fuel flow meter, and connect it to a fuel management Gage. These are generally dead on, When you fill the boat up, zero it out, and you will now know exactly how much fuel is left by subtracting how much fuel you have burnt on the fuel management gage. If you have a 100 gal tank, and the gage says you burnt 20 gallons, you have 80 gal's left. They are usually within 1 gallon at fill-up, very accurate.
2. Keep a VERY tight log of your usage. Track the hours of usage (from time you start motor to time you shutdown motor). Use your GPS tracks to monitor and log your travel distances. And lastly, log each and every fuel fill up and gallons used. After a month or so, you will know EXACTLY how much burn per hour, and/or how much you burn per mile (MPG). Now anytime you use the boat, simply do the math on your usage to compute how much fuel you have left. I use this method on my Rampage, I have a 250 gallon tank and when I fill up, I estimate what I will require to fill, and am usually within 5 or 10 gallons when filling up between 150 to 200 gallons. That's pretty accurate.
I even know the difference of my fuel burn based on the types of usage. When I run out to the canyons, my burn rate is much higher than when I am fishing locally. The reason being out to the canyons I'm running it hard for 4 hours each way. When fishing locally I only run hard for 30 minutes or so each way, and the rest is idling or moving over a mile or two.. so I take this into account when figuring my fuel burn.
After each trip, I make an entry in my log book, Date, description (what I did/where I went, with whom..), Engine Hours, Distance Traveled and Estimated Fuel burn. I figure the fuel burn on the hours I used it, the type of usage (offshore, local,...), and sometimes the distance traveled based on my GPS log. I can easily add up my Est. Fuel burn column from the last time I fueled up, and see approx. how much fuel I have left. Using the 1/3 reserve method, I know my estimate is always good enough to safely get home...
Thank me later for saving you 1000's of dollars from replacing your fuel sender units every 2 months. To me, they work as good the paddle wheel speed senders on transducers. USELESS.
I have owned and operated many boats in my time,,, NOT ONE OF THEM have EVER had a fuel tank sender / Gage that worked longer than 1 or 2 weeks. They are absolutely useless!!
Bird, you just never installed the right sender/gauge combination.
Yes I did. They just have NEVER made a sender unit, that works longer than 2 weeks. Either the float rots out, the sender itself electronically gets corroded and stops working, or both.
Well you certainly have had a vastly different experience with senders than most folks. You seem to be hell on wheels with your senders , no offense intended. On my present boat only one of the 2 very good Rochester swingarm float senders had to be replaced after nearly 20 yrs. They are the model 8741 : http://www.rochestergauges.com/Pages/PDFs/8700.pdf . These work great and keep needle movement surprisingly steady and everything inside the tank is strictly mechanical, but in general I prefer the no-moving-parts & calibratable Centroid products capacitance tube senders I put on my last boat.
On the boats I've had for the last 40 yrs or more, I'd guess I've replaced maybe 5 or 6 senders that went bad , all cheap swing-arms, and even they lasted pretty long . Some are just better in most respects than others. And yes I do a lot of very rough saltwater boating and yes I do have 2 different add'l fuel management systems(F/S 9000's and B&G NetEngine) and do maintain a written log of fuel ,hrs , distance log and other data. . They don't take the place of a relatively decent gauge/sender setup that complements the electronic stuff. There are even built-in mechanical/magnetic gauges on top of the Rochester senders for a reality check when batteries are disconnected.
Yes I did. They just have NEVER made a sender unit, that works longer than 2 weeks. Either the float rots out, the sender itself electronically gets corroded and stops working, or both.
Use a log!!
Are you saying that you have tried both a capacitance probe type and an ultrasonic type sender and they both were problematic? Jethro be sceptical since his results vary from yours.
Is it OK with you if a Delta pilot on a transoceanic flight uses a fuel flow meter and/or a log to keep track of his fuel? The FAA would disagree with you of course. And yes, I know, flying is not the same as boating. But...
Birdman, my gas gauges and senders typically last for at least 10 years, something is wrong with whatever products you have been using or with the installation.
Running out of fuel is dangerous and foolish. Like an airplane, it should be monitored by different systems. I use three:
1. Gut feel: the boat does not get used with less than1/4 tank left.
2. Fuel used reset: The fuel used is monitored every time I go out and reset with added fuel
3. The sender level: The sender has worked well for 5 years and reads approx what the fuel used calc says.
Sending units are worthless. Install a Floscan & you can't go wrong.
Respectfully disagree. I have 2 good Floscans and love them but wouldn't want to be without a good sender and gauge for the reality check. If floscans are not reset after every fill , or if the tanks are not topped off at fill, it's the Floscan totalizer that is nearly worthless. And one can make the sender gauge system surprisingly accurate by adding add'l register marks to the gauge bezel and diagraming in your logbook the needle position just before fill and the amount pumped each time.
Problem was contacts on the outside of the sender. I somehow forgot to hit the connections wjth dielectric grease during install. Thanks for all the feedback will consider a floscan this spring.
Another option from the flow-scan. Most of the newer chartplotters have fuel use monitors like the flow-scan. They need a sensor in the fuel line of course for $150-$200.
fuel guage or sender? 
