When I bought my boat three years ago I filled up the fuel tank and added the recommended amount of Biobor JF. Over the intervening three summers I have managed to use up almost 1/8 of that tank of fuel which is now three years old.
My question is about what I should be doing going forward. Do I fill up the tank every fall and add a bit more Biobor thus dooming myself to having a fuel tank full of fuel that it at least three years old (and mostly considerably older as time goes on), or do I just keep using the fuel up? After another 15 - 20 years the tank will be getting down and I will be able to refill with fresh fuel.
I know that one obvious option is to suck out some fuel every spring and replace it with some fresh, but this would be a dirty job and seems wasteful. My fuel tank doesn’t have an inspection port and is prone to leaking around the fuel sender for some reason. I have just managed to get that leak stopped, so I don’t really want to be removing the sender on a yearly basis and opening that can of leaky smelly worms again.
My bottle of Biobor JF is now three years old as well so, according to the label, it has now expired. I will need to dispose of the 98% of the product still in the bottle and get some fresh stuff before I do anything with my fuel tank. I wonder if this means the stuff in the tank has also “expired” and that I need to add enough new stuff to treat the entire tank, or only enough to treat any additional fuel that I may add to top the tank up for winter?
Such are the “problems” of day sailors who uses their engine for a few minutes at a time to get in and out of their marina slips!
Thanks for any thoughts and feedback on this matter, and Happy Thanksgiving (to all the Canadians out there on this forum).
One suggestion would be to take an annual trip (or a couple of day trips) in “powerboat” mode. We all have friends who are timid about heeling over who we might none the less like to show our boats off to. Pick a nice calm sunny day when you’d love to go sailing and go anyway only under power.
You will likely enjoy the beautiful day and as a bonus you will make your fuel problem go away.
I would remove it without giving it another thought. Buy a new gasket for the fuel gauge sending unit and go that way. If not, there should not be any obstruction in the filler hose and you can pass a hose down it. The sending unit access is better in that you can get a rigid hose to the lowest point in the tank. The added benefit is that any water in your tank is at the very bottom. I suck out the very bottom of my tank every spring and never have fuel problems.
Joe Valinoti
S/V IL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
I do not use a biocide, just some kind of additive. We don't have to haul or winterize our boats here in Eastern NC. The hurricanes like Florence does if for us. Just kidding. I come out for a month in January for cleaning and one coat of bottom paint. I do fill the tank for the winter.
Joe Valinoti
S/V IL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
I used to fill the tank for the winter prior to the introduction of low sulphur fuel that uses a steam process to remove the sulphur. The process leaves a high moisture content in the fuel that settles to the bottom of the tank over the winter. For the past several years I have run the tank down as far as I dare and carry a small reserve tank just in case. In the spring, I make a point of purchasing high cetane diesel to refresh the tank. It lets the engine run smoother and quieter with less soot and less transom to clean up. During the summer I let the engine run sufficiently to reach operating temperature. Often starting the engine when I arrive on board and then putting it in forward or reverse to give it some work to do. (I am on a dock) I suppose one could have it in reverse on a mooring, if you are sure it is secure. By reaching operating temperature for a few minutes any water in the oil should evaporate. It does a diesel good to let it run near full throttle for a few minutes once it is fully warmed up.
John Newell
Mascouche 26C#1 with a 1981 16 hp Universal diesel
When I converted my Nonsuch to Electric Propulsion I still had about twenty gallons of diesel fuel that I had to remove. It was easily done with a Topsider unit: https://biankablog.blogspot.com/2008/03/removing-diesel-from-fuel-tank.html
I donated the fuel to a local commercial fisherman who decided to use it in his home heating system since his boat was in the yard for repairs.
I know the picture has changed with the advent of low sulphur and/or ethanol admixtures in our fuel but, in the 35 or so odd years that I have owned a diesel auxiliary sailboat, the only time I have ever had an issue with water in the fuel system sufficient to affect the operation of the engine was the 1 year that I did not top off the tank before laying up for the winter. Maybe that was coincidental or just the result of many years of accumulated contaminants of one sort or another but I will never lay up our boat again without topping up the tank and adding a little Sea Foam and Biobor.
FWIW: I no longer have a diesel but learned an important lesson while I had one: check the O ring in your deck fill cap.
One surveyor had a blog and said most of the “water condensation” worries with fuel were not well founded; much more likely were O ring issues allowing water to enter via fuel fill cap. I checked mine and not only was O ring cracked but the weld inside cap had broken such that it couldn’t seal properly even with perfect O-ring. All this prompted by having to change fuel filter 5 hours into maiden voyage to home port - in middle of Chesapeake Bay.
I subsequently removed fuel tank, thoroughly cleaned it, replaced a plastic inspection port (it leaked) with a larger, $200 or so metal one and never changed another fuel filter for the next roughly 3000 nautical miles of motoring - Bahamas and back with about 300 miles of sailing
When I bought the boat 11 years ago the fuel was black. Easy to check by looking at the racor water separator, if your fuel is clean it looks like honey or beer, if it is dirty it looks like Guinness. It also had water in the bottom of the racor that had to be drained.
The engine seemed to run fine on this black fuel but I didn’t fill the tank for 3 years trying to empty it to the point I could lift it out. It leaked and needed repair.
One tiny weeping leak was at a poor weld from the factory. One big leak was at the sender. The sender leak was because the tank was not flat at this point and the gasket never properly sealed up to it.
I cut 1/3rd of the tank off when I opened it and cleaned all the black sludge out, there was maybe a cup full of sludge and the entire inside was covered with black scum. Had the end welded back up properly. Fixed the sender leak with blue gasket maker from Canadian Tire and I added an inspection port in case I had to clean it again..
The tank now does not leak at all, the fuel is clean, never has water in the racor, and the smaller tank would easily last two summers except for this summer when there was no wind. I fill the tank in the fall before layup. The old filler O ring was replaced. As a bonus I now have a convenient wine cellar where the forward end of the fuel tank used to be.
Lots of folks use those senders, but given the shape of the tanks it is a guesstimate at best. We simply track engine hours and multiply by ,4 the consumption rate of my W21. Works very well to a point that I removed the sender years ago and sealed the hole with a plate and some silicone …
Yes the sender is inaccurate even when it works. Another way, with the shortened fuel tank, is to tap the forward end with a knuckle and by listening you can hear where the fuel level is. Or just pick it up and shake it. If you can, it’s time to refuel.
Our gauge seems to work but I don’t have a lot of faith in the indication.
As you point out, partly because of the shape of the tank. To be clear, when you say you multiply by 4, I assume you mean 4 L/hr, not 4 US GPH or 4 IGPH? Or is the value 4 related to some other metric?
My sender seems to be pretty accurate and reliable. It’s not a complicated device. It’s possible that when they are installed, the float is not bent to conform with the tank.
Joe Valinoti
S/V IL Gatto NS30U #221
Sea Harbour YC
Oriental, NC USA
Y’know … there is always the possibility that these engines might actually run better if the tank WAS, indeed, filled with Guinness. Then again, how would I know - I have an outboard ??
0.4 US gallons per hour is what we use. Now that number takes into account we rarely “motor” any longer than getting into and out of an anchorage. If I was motoring all day it may rise to 0.6. With a 25 US gallon tank I base fuelling on 20 usable gallons and generally fuel at around 10 gallons. I ran the engine for 30 hours lat summer over total 480 miles …
