Just returned from a 10 day Keys trip. Did not want to come back but was getting lazier by the day and I have to pay the bills somehow. Anyway, I did something I swore I would never do (shut up Pea) and ran out of gas at sea. I have never done this before and never had an issue with my fuel gauge until last week. We were heading in from a few miles out with the fuel gauge reading 1/3 full when the engine sputtered and died. I tried to re-crank it but, could not keep and pressure on the fuel bulb. Thankfully, I had just renewed my BoatUS membership so I gave them a call. 30 minutes later, 2 ladies pull alongside in a red boat and pass me 5 gallons of gas. Yaay for Towboat. Fueled up and it cranked right up.
My question is, what should I look at as the culprit, the gauge or the sender? The gauge is only a couple of years old, the sender is 12. How do I tell what is bad and, if it is the sender, how hard is that to replace?
Thanks
“Apathy is the Glove into Which Evil Slips It’s Hand”.
The sender varies its resistance to the ground (-) depending on the float level. If you ground the sender wire to a negative source the gauge should peg to the full side. No peg, bad gauge. Usually the gauge is not the problem. 
Does your tank have a gauge on the top as well? Mine did. Mine also did the same thing you’re talking about. If at all possible take the 2 wires going to the gauge and touch them together with the key on(just for power). If the gauge goes to full then it’s the sender. Fortunately on mine all I did was take it apart and clean the heck out of the ‘oxydized dust’ (for lack of better term) that built up under the gauge itself, put it back together and it works like a charm. I sealed it a little better with some epoxy and it’s been good ever since…What I can remember from what I’ve read if the guage is bad you can use a volt meter at the 2 wires on the back of the gauge and read 1 to 5 vdc …1 empty , 5 full…then replace as needed. …I’m sure the guys with a little better knowledge will correct me where I am wrong…Hope this helps
Fishing Nerd
“you win some, you lose some…but nothing beats getting some!”
If you can reach the tank bottom from the filler, cut a piece of pine board 3/4" x 3/4" and about 3’ long. Next time you fill the tank use a marker and mark the wet spot every 10 gal. It will never let you down! be sure to mark the top so you wont put it in upside down!
are you sure your tank was actually empty?
you may have a bad pick up tube and the sender and the gauge are both perfectly fine
pump all the gas out through the pick up tube, then pull the sender and see if its actually empty.
if its empty, replace the sender and the gauge and the wire, probably less than $100 and 1-2 hours.
replace it with a WEMA sender and be done.
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Actually, I don’t really know if the tank was empty. The motor sputtered and died and there was no pressure on the fuel bulb. I am kind of skeptical about being empty as I had “some” fuel left from the previous day and put 5 more gallons in that morning. We’re talking about a 19 gallon tank with a Yamaha 70 TLRB. It is normally pretty fuel efficient and we had only run about 10-12 miles at 3/4 throttle.
I am handy and capable but, not familiar with the fuel systems on a boat. Do I remove the sender to get to the pickup tube?
Thanks
“Apathy is the Glove into Which Evil Slips It’s Hand”.
nope
pickup tube is attached to the fuel line where it connects to the tank it will just unscrew from the tank
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Doug, call me if you can’t figure it out. I know somebody who can.
Capt. Larry Teuton
Swamp Worshiper
As always Larry, THANKS! I may give you a call when I get time to tackle yet another project. My list of “to dos” seems to be growing.
By the way, the Lewmar Claw anchor rocks. Got hung up 3 times and each time just nudged the boat forward and no problem. That was a great tip, thanks!!
“Apathy is the Glove into Which Evil Slips It’s Hand”.