Wrong primary filter?

[Porchhound]

Looked into the specs and this 2micron is really a 4micron @ 98%. Based upon wiki: "Note also that a 4ų cartridge is not recommended to be used as the primary filter." This one was recommended by a Kubota heavy equipment dealer:Fleetguard FF5226 (98.67% efficient @ 20ų; 65% efficient @ 2ų). Which is better...the Fleetguard or Racor R25S currently on there?

[Porchhound]

Also I found this in spare parts. Is this adequate as a secondary filter?

[KWKloeber]

You may be confused about primary and secondary.  The filters like NAPA, Universal, Fleetguard are secondary/on-ebgine.

A Racor (Parker) 10u filter cartridge is fine for your primary.

I've posted b4 that the filtering is a$$-backwards.  The coarse secondary filter should be first and the finer one next, but such is life with our engines.  In practice it probably doesn't mean much, it's just incorrect.

[Porchhound]

So the PO has a 4micron on his primary (R25T)...which should be a 10 micron?

[KWKloeber]

That's what Racor recommends.
The issue is, running a tight filter as the first upfront can clog more easily.

Consider this - hundreds of thousands of Kb tractors have run for years with only it's coarse, Kb on-engine filter.
And as well probably thousands thousands of boaters have run 4u primary w/ no problem.  It depends primarily on the fuel!

[Porchhound]

Yeah, I see the wisdom of reversing the recommendations. Thanks. Looks like his spares are all secondary the say he has it set up. I didn't see another 2/4micron for the primary. The 10micron filters are small...I guess to fit under the alternator upgrade.

[Stu Jackson]

Yeah, I see the wisdom of reversing the recommendations. Thanks. Looks like his spares are all secondary the say he has it set up. I didn't see another 2/4micron for the primary. The 10micron filters are small...I guess to fit under the alternator upgrade.

This 101 Topic answers your filtration questions:

Fuel Filtration 101 (with both primary Racor and secondary engine filter identification)
http://c34.org/bbs/index.php/topic,1124.0.html and http://c34.org/bbs/index.php/topic,6475.0.html

There are two schools of thought on this:
1)  Use a coarser primary filter (under your head sink) to allow the secondary on engine filter to do its work per industry filtration basic recommendations
2)  Use a finer primary to avoid loading the secondary since the primary is so much easier to change on our boats due to their locations

Over the past 25 years on my boat I have done both.  I have seen no difference at all in operations.  In fact, I used a 2 micron primary for the past five years and once went 900 hours without changing the primary filter.

My conclusion has been that the sheer volume of fuel passing thru our filters is tiny compared to the capacity of the filters.

I believe you are confusing the oil filter under the alternator with the secondary fuel filter on the starboard side of the engine.

[Ron Hill]

Porch : Forget about the primary and secondary nomenclature - You have a a Racor filter (first in the fuel line) before the fuel pump and a engine filter on the engine.  I use a 2 micron on the Racor and a 15 micron on the engine (just before it enters the injection pump on the engine). 
I change the Racor every spring and the engine filter every 5/6 years and have NEVER had a fuel problem in 25+ years!!!

A few thoughts

[Porchhound]

Thanks, Ron. I'm having problems sourcing the the primary in time for my departure date. West Marine takes a week to get them here. I'm still looking online.

[Noah]

Auto parts stores or Amazon?

[KWKloeber]

Thanks, Ron. I'm having problems sourcing the primary in time for my departure date. West Marine takes a week to get them here. I'm still looking online.

@Hound
What are the Racor "spares" that you had aboard?  Aren't they for yours?  What Racor do you have?
Where is "here"?

Don't you have the "normal" Universal spin-on secondary filter?


@Ron
Where did you locate a 15u spin-on?  Brand/mfgr?

[KWKloeber]

https://c34.org/bbs/index.php/topic,11517.msg92988.html#msg92988

Eng2 pic - the dark can (brand?) is your secondary fuel filter.  It's probably a 25u (nominal) filter.  It looks like a Universal, (Ice Blue) the current color of Universal engines.  The Fleetguard filter has significantly higher efficiency.

Note also that there is a filter, actually a screen, in the bottom of the Facet fuel pump.  The bottom of the pump twists off wth 1/4 turn.  You can flush it, or NAPA has it (check the wiki.)  It's a screen so it doesn't catch anything much unless the fuel tank has a ton of junk in it or the pump was originally plumbed incorrectly and was first in line off the tank and caught some diesel bacterial snot.  Before someone says it, "algae" (plant life) does not grow in diesel fuel.

Eng4 pic - the white can is an OEM oil filter.  I prefer the Fram or Fleetguard, but YBYC (Your boat, Your choice.)