Lehman 120 Question - please help

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Arch

Senior Member
Joined
Sep 2, 2012
Messages
180
Location
USA
Lehman 120. How much fuel gets recirculated? Gallons per hour.

I am still struggling with water in the fuel and am trying to gauge when I might be clear of water.

I am currently looking for possible ways for water to be getting the 10 year old aluminum tanks in case it was not a bad fuel problem. I have so far pulled 4 or 5 gallons of water (yellowish along with crud) out of the tanks.

Thanks,

Arch

PS Currently in Georgetown Bahamas
 
I don't understand why recirculated fuel has anything to do with water in your tanks? Your engine would be toast if any water got into the fuel injector pump, which is why there are elaborate filter systems. The recirculated fuel is to cool the injectors and the injector pump.
 
The FL 120s and 135s return ounces per hour. They return probably return the least of any of our marine diesels.
 
Almost nothing gets returned to the tank...maybe a few Oz an hour at best.

I have tested...only a drop in 15 minutes at 1000 rpm.

I accidently left a return line closed one time for hours...no problem.

Bob Smith from American Diesel used to teach classes in a parking lot and from what has been posted by others is the return line was never hooked up as so little came out for demonstration purposes
 
Thanks guys!

The thought behind this question was that at some point enough fuel would be "cleaned" by the filters through recirculating that I could be reasonably certain that I has gotten it all. Obviously not the case.

I will continue the fight. It is a little frightening when off shore, in a foreign country when the engine stops several times.

Arch
 
If you have a good primary filter, like Racor, that's designed to remove water, plumb in a temporary pump to circulate thru the primary and return to the tank. Let it run for days. It can be run while running main engine as long as the filter flow capacity can take the increased flow.
I found the best way to introduce water into fuel tanks (besides a fire hose) is to buy fuel from small suppliers, especially marinas that only cater to yachts. I've seen dated filters on the pumps that were decades old or Racor types with water filling the bowl. Ask when the filters were changed or if they even have filters.
 
Of course there's always the danger that water is in the fuel you purchase, especially in smaller out-of-the-way places. But it can also come in small quantities (basically water vapor or humidity) through the vent line. We have Lehman 120s and use H2Out Air Vent Dryers. We used one on our previous sailboat, too, which was when we made the video: https://youtu.be/2TwMNQfQeNI

Let me know if you want one or two Arch, as I have two left in stock. They're the first generation AVDs which have the clear canisters, so I can make you a Trawler Forum deal...
 
Check your fuel fill o-rings for cracks and your fuel tank vents for the holes should be facing down and aft.
 
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