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  Topic Review (Newest First)
03-28-2013 05:37 PM
Re: Racor Diesel fuel filter 500MA2

Going to find a pile of O-Rings for my fuel fills. Much cheaper and it sounds like the really solution to the potential problem.

Maine - do let us know how your testing of the H2out goes.

03-28-2013 04:26 PM
Re: Racor Diesel fuel filter 500MA2

Thank you, great info as always!

This is getting very expensive, and I have two tanks, ~$450 total, ouch.
03-28-2013 04:02 PM
Maine Sail
Re: Racor Diesel fuel filter 500MA2

I've got one going in my own boat to do some testing on. In 40 years of owning boats though neither myself or my family have ever once found any water in our tanks. I change my deck fill o-rings about three times per season....

IMHO most water in tanks comes from the vent leaking or the deck fill leaking...

I once installed a tank clean out port on a customers Cape Dory. She had her deck scuppers clog over the winter and before I even had a chance to put fuel in the now clean and empty tank, the tank it was 2" full of water even under the winter cover....

Empty tanks don't magically fill with water, if they did we would not need water wells... I replaced her o-ring, (it was completely missing) drained the tank and all was fixed...

Keep in mind that the "dehumidifier" is only part of your cost. You'll need a Racor LG100 or similar ahead of it in the vent line to protect it from "burping" fuel up the vent line and into the dehumidifier..... The LG100 runs about $110.00.....
03-28-2013 12:29 PM
Re: Racor Diesel fuel filter 500MA2

Maine Sail

I am thinking about adding this to my fuel tank vents. Seems like a great idea to me. Not cheap, as is typical for marine stuff.

03-27-2013 10:44 PM
Re: Racor Diesel fuel filter 500MA2

Thanks a lot Maine Sail,
I am installing a new motor and working out the electrical and plumbing logistics of what I need, the 2 micron filter seemed like it would be prone to clogging and putting a 10 micron after a 2 just didn't make any sense.

Are the cheaper spin off Racor fuel filters any good? I heard they have problems out of the box because they won't unscrew and I don't think they meet AYBE? specifications.

Now I need to add 'Clean fuel tank and install inspection cover' to my do list.
03-27-2013 11:54 AM
Maine Sail
Re: Racor Diesel fuel filter 500MA2

2 micron filters should really not be used for a primary filter. They will clog faster, require more work from the lift pump and is really filtering well beyond where any manufacturers engine needs to be. People just automatically assume 2 micron is better and in many cases it simply shortens the life of a lift pump and clogs when you least want it to.

Racor specifically suggests 2 micron filters to be use as a "final" filter not a primary or even a secondary. Course if you have a clean tank and dedicated on-board polishing system them a 2 mic primary may be okay. In most instances a 2 mic can be fine as a "secondary filter" too.

We have a new tank and a dedicated purpose designed high capacity, high flow on-board polishing system that polishes the fuel to 2 micron and turns the tank over multiple times per hour. Despite spotless fuel and a spotless tank our primary engine filter is still a 10 micron so as not to over work our electric lift pump.

Racor does not even really call the 10 micron a "primary" filter. They refer to the filters as:

30 Micron = Primary Filtration
10 Micron = Secondary Filtration
2 Micron = Final Filtration
03-26-2013 11:20 PM
Re: Racor Diesel fuel filter 500MA2

why is the finer filter before the coarser filter?
03-26-2013 10:22 PM
Re: Racor Diesel fuel filter 500MA2

Mine reverse first in line 2 Micron then 10 Micron
03-26-2013 11:49 AM
Re: Racor Diesel fuel filter 500MA2

My primary is 10 Micron (racor) and the secondary is 2 micron
03-26-2013 10:44 AM
Re: Racor Diesel fuel filter 500MA2

I use 2 Micon
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