E32-200 Fuel Filter Microns

[frosero7744]

Hey all. Searched for a similiar thread but came up short.

I changed my primary and secondary fuel filters on board this last weekend. Yanmar 3GM30F. Both are 2 Micron filters. My friend that helped me commented that since my primary was 2 micron i really didn't need to change the secondary very often or at all maybe. Which since access is not ideal is a good thing i thought. Since then I've heard every opinion in between.

Golden State had a 20micron in the primary. I think Christian may have cursed the 2 micron primary whilst rolling about on the big water.

Thoughts? Comments?

 

[Frank Langer]

It's one of those topics like which anchor is best. The 2 Micron primary or secondary filters will filter best, but could get clogged more easily, so some experts recommend a 10 Micron for the primary filter.
I have used a 2 Micron primary for years, never had a problem, but I'm very careful about where I get fuel and always use additives to prevent algae growth and improve lubricity.
Frank

 

[G Kiba]

Switching from a 2 Micron to a 10 Mircon for me made a noticeable performance improvement with no temperature rise when motoring longer that an hour.

 

[Alan Gomes]

2 micron is too fine and hard on your lift pump. Go with 10.

 

[Kenneth K]

Came across this while looking for fuel filter replacements. https://www.pegasusautoracing.com/document.asp?DocID=TECH00100

"Fuel system final filter (after the pump): 1 to 40 micron. High-performance fuel injector manufacturers recommend a 10 micron or finer filter."

Since out mid-80s tractor engines hardly qualify as high-performance, I'm guessing 10 micron is plenty small enough.

 

[Pete the Cat]

I believe all new Yanmar marine engines come with a 10 micron primary filters and 2 micron secondary filters. Although their customer service stinks, I much respect their engineering expertise when it comes to engine testing and design.

 

[light24bulbs]

I have read that it depends what kind of injectors you have, with the more modern injectors having much tighter tolerances and dealing with higher pressures.

EDIT: I see you've repowered, my mistake. All bets are off from me.

Since we are talking about tractor engines from the 1980s, I don't think they use the new modern type of high performance injectors. Which leads me to believe that 10 micron secondary would be okay. Maybe somebody else more expert can chime in.

Don't you want the primary filter to be much bigger, like 30 microns? Isn't the idea that it will catch the big chunks and the secondary will catch the small chunks?

 

[Kenneth K]

No recommendation is one-size-fits-all.

Sure, if you've installed a new fuel tank recently, or fitted your old tank with clean out ports and subsequently scrubbed the insides clean, then running 10/2 micron filters may be fine, whether the engine really needs a 2 micron filter or not.

But for the majority, with dirty, decades old tanks, the 30/10 regime probably makes a lot more sense.

 

[Alan Gomes]

No recommendation is one-size-fits-all.

Sure, if you've installed a new fuel tank recently, or fitted your old tank with clean out ports and subsequently scrubbed the insides clean, then running 10/2 micron filters may be fine, whether the engine really needs a 2 micron filter or not.

But for the majority, with dirty, decades old tanks, the 30/10 regime probably makes a lot more sense.

It's not just about the cleanliness of the tank or fuel. 2 micron filters make the lift pump work harder and can shorten their life.

 

[Alan Gomes]

From MaineSail: https://forums.sailboatowners.com/threads/question-about-racor-filters.184429/#post-1362613

 

[Kenneth K]

It's not just about the cleanliness of the tank or fuel. 2 micron filters make the lift pump work harder and can shorten their life.

The research I've done claims that a clean 2 micron filter is no more restrictive than a clean 10 micron filter. But, obviously, the 2 micron filter will trap smaller particles and, thus become clogged and restrictive sooner.

"Damage" to a lift pump would only occur with a clogged filter, so I maintain that the condition of the tank, fuel, and other filters does matter.

 

[light24bulbs]

I don't mean to hijack the thread, but has anyone hired/rented a fuel "polisher" or made their own? I've just purchased a boat that hasn't been used much in several years (old fuel) and I need to sail it home about a hundred miles, and there may be some wave action. I'd really like the motor to work throughout the voyage.

The previous owner has always put in fuel-treatment including what's in the full tank now (and I believe him on that, he's a dentist).

I need to replace the filters anyway. Has anyone used the onboard fuel filtering system as a polisher? I feel like I could just take the fuel line off of the engine and loop it back into the tank and run the lift pump for a few hours to make sure everything is cool, followed by replacing the filter. Bad idea?

 

[Pete the Cat]

I used to do deliveries and have some experience with this dilemma. A couple of facts: The regular fuel system on diesel powered boat is a kind of fuel polisher; it circulates the fuel (if the engine is run enough) in the tank through the filters constantly because there is a return line from the injectors for the excess fuel that is not burned (unless you have one of the new common rail diesels, which I doubt). This stream is substantial. This is why your fuel tank gets warm after running for several hours. I recognize the dilemma you have, but I definitely would recommend NOT adding any biocide before taking any offshore trip--don't ask how I learned this. You do not want to knock anything loose if stuff is growing in there. If you have an ability to stick a tube to the bottom of your tank (on most boats, the deepest part of the tank is directly under the gauge sending unit and sucking whatever is down there might be useful, but I would go no further in prep (other than filter changes) before taking your trip. Also, algae has a habit of growing on the sender units themselves and will give you a good idea of the condition of the tank's cleanliness. What i would do in your case is get a few 10 Micron primary filters and have at least 2 of the secondary filters on the engine (these are usually 2 Microns) and pick the calmest day you can find for the trip. If the engine is running now, I would be careful about fooling around with the connections or making a lot of changes before heading out. I frankly am skeptical of the effectiveness of professional fuel polishing enterprises because typically--unless your tank has a large access port in the top of it, they really have trouble getting the guck out from behind all the baffles (most tanks have several) and your engine is already doing what they do if you run it a bit--they really cannot do more. The 10 Micron filters can trap an amazing amount of stuff before the engine will stop. If the engine does stop, it will most likely be some crud in the pickup tube or fuel line (blow backwards into the tank) or your vent is clogged (spiders like to build nests in there for some reason). i would most careful about messing with a working setup prior to a long voyage. Better to do serious disassembly of your fuel system when you get to your dock and have time and resources and less risk. Just my opinion I am sure others will have different ideas.

 

[Kenneth K]

I feel like I could just take the fuel line off of the engine and loop it back into the tank and run the lift pump for a few hours to make sure everything is cool, followed by replacing the filter.

That would "polish" the free, liquid fuel in the tank, but wouldn't do anything to remove or reduce the hazard of slime/sludge on the tank walls, that may only be stirred up under, as you say, "wave action."

 

[Loren Beach]

Ray has some good advice.
I would only add that a friend of mine with thousands of miles of ocean deliveries successfully used a great strategy to get a (delivery contract) boat all the way up the WA coast from Astoria. The engine had not been run much before he took off, and he got down the river from Portland with several filter changes. The fuel tank was obviously crudded up.
Once in Astoria he bought several cans for diesel fuel, and also a six gallon fuel tank normally sold for OB use. He ran the hose from the new six gallon tank to the engine (it was a smaller 3 cylinder engine IIRC) and just added more diesel to this new "day tank" arrangement whenever it got low. I believe that he delivered the boat to the Seattle area with no further problem. Delivery was on time, and owner was happy--- and then had to trouble shoot the whole fuel tank and hose system.

Proof only that, in the short term, there may be more than one way to solve a problem.

 

[Pete the Cat]

That would "polish" the free, liquid fuel in the tank, but wouldn't do anything to remove or reduce the hazard of slime/sludge on the tank walls, that may only be stirred up under, as you say, "wave action."

I agree. The problem is that unless you are going to get into a dirty tank physically, (and that means seeing directly between the baffles in the tank and working it with a brush, and removing the sending unit and pickup tube for physical cleaning), the process of passive polishing or just sticking a somewhat pressurized nozzle through the 2" hole is not likely to really clean a gunked up tank. I am very skeptical of folks who advertise fuel polishing services because your engine constantly does what I have seen most of them do; circulate fuel through the filter without burning it. A boat that has been sailed and motored regularly is constantly "polishing" its fuel in a similar way and sloshing and heating the fuel while it is doing it. Boats that sit for long periods and have moisture in the tanks grow stuff and this stuff feels like very sticky, gooey, night crawlers when you remove it--I have tried to imagine how the fuel polisher folks think their systems are going to get this out by simply by doing little more than what the engine and boat motion does constantly. This thread is going a long way from where it started but here are some hard earned lessons from deliveries and passages:
1. Don't make big changes in your fuel system (biocides, plumbing changes) to a smooth running engine before a long trip. Unless you can actually see what you are doing through an access panel in your tank, you are just as likely to knock a chunk of goo into the mix and gum things up as make things better (obviously I have a couple personal experiences with making this mistake--one of them left be bobbing in the Bay of Fundy shipping lanes waiting for wind).
2. Nigel Calder recommends sumping your tank annually (or at least regularly) through the sender/pickup hole to remove water and debris from the lowest point in the tank. This will tell you the health of your tank and whether you have moisture (which is what is needed to grow stuff in diesel). The condition of the sending unit is an indicator. Because I sail and motor my boats alot and use BioBor regulalry they are generally clean, but you know the history your boat.
3. For longer term management of this problem, you should ensure that your do not have a screen on your pickup tube. Most production boat manufacturers stopped doing this in the late 80's, but I do not know what Ericson did. It is dumb idea and you should knock it out as it will only cause a difficult problem to resolve if it clogs offshore--it is no problem to change a filter, but it is really bad if a screen gets clogged (yes, I have experience with that). You also need to know that the vent line is clear (don't blow into the tank) and that your O ring on the fill cap is good--this is a good place for water to seep into the tank and provide the basis for algae growth.
4. I realize others will differ in opinion, but using a 2 Micron primary filter is an unnecessary risk. My fellow Mainer, MaineSail has a story on his website about a delivery where that caused an enormous number of problems and delays. I think the story is still there if you are curious. I got away with 2 Micron primary filtter for years (under the flawed belief that "some filtering is good, more is better") and then I didn't. Not fun.
Just a perspective based on my experiences and mistakes.
FWIW.

 

[light24bulbs]

Thank you very much. I didn't realize this was something that fuel system was already doing. I'll run the engine at the dock for a few hours at a medium RPM and make sure it doesn't quit and I'll see how the filters look.

Steps for me now are to open the tank and do a visual inspection of the tank interior and of the sending unit/fuel pickup. I will remove the filter screen on the pickup if one is present. I will also check the fuel fill o-ring.

I will dip a hose down there and pull some diesel out of the bottom and see how it looks. In particular I will look for water.

I will buy extra 30 micron (primary) and 10 micron (secondary) filters and keep them aboard.

This is my first diesel boat so thank you very much for helping me make my delivery safely.

 

[Pete the Cat]

Not sure if running the engine at the dock will knock anything loose that might be hanging there. Assuming you do not have an inspection plate (most production boats don't) I would suggest that you take out the sending unit (and the pickup tube if it is not welded in place) out and examine it for guck hanging on it and sump the low point of the tank. If you do not find much here and if the pickup tube does not have a screen, i would skip running it in place. Doubtful there is much potential for a problem. . If you find a lot there, you need to do what you can to clean it up and then run the engine for a bit at the dock to make sure things are more or less clean. As I mentioned, it takes a fair amount of goop to stop an engine, but I have had it happen. if the guy has been using Biobor any real guck should be at the bottom and you will see it in what you suck from the low point in the tank.
I would be sure of the engine manufacturers recommendation of primary and secondary filters---the Micron sizes you mention seem very large, but they do vary by engine. Another thing you might do is buy a borescope from Amazon to look at the tank--you can buy a decent one for $80 these days and it will save you a lot of time looking at things (like inside the tank and inside the exhaust and water systems) in and around your diesel (and around the house as well). I presume you have inspected the raw water pump and systems before your trip--I would never start a delivery without seeing the impeller on the raw pump--and having a spare. All lessons i had to learn the hard way.

 

[Alan Gomes]

I realize you can go nuts with all manner of modifications to your current setup. However, assuming that you have no particular reason to question the cleanliness of your fuel and tank, I think I'd change your setup so that you have a honkin' big filter that is easy to change and to bleed while underway, just in case.

To wit: (1) Go with a Racor 500 filter. These cartridges, in addition to being cheaper, can be easily changed without slopping fuel all over your cabin. (2) Replace your mechanical lift pump with an electric one. This is a good idea for a few different reasons, but one happy byproduct of doing this is that you can easily bleed the engine if you wire/plumb it correctly. (See next point.) (3) Using a Y-valve and a switch in the engine compartment to energize the electric fuel pump, you can have one side of the Y tap into the injection return line, which in turn goes straight to the tank. The other side of the Y goes directly to the engine (i.e., where your mechanical pump used to connect). When you drop a new filter into the Racor housing, you have the valve set to divert the fuel from the pump into the return line. When you throw the switch, it will fill the empty Racor housing with fuel. Then, you turn the Y-valve to send the fuel to the engine, under pressure, and crack the engine bleed points until you are getting solid fuel. Shut off the switch and you are done!

Again, the beauty of this is that you could do it even on a pitching boat in a matter of minutes. The Racor 500 has huge filtering capacity and it would take quite a bit to clog one. But just keep a bunch of them on board if you think filter clogging may be an issue (the filters are relatively cheap). Changing them is a breeze, especially with the setup I have described.

 

[Christian Williams]

Here's my take: 2, 10, even 30 micron primaries work if they work. My Previous Owner left me six 2-microns for the Racor 500, and I'm still using them after 10,000 miles. (I did choose new 10-microns as backups).

So, do your filters work? They don't if the engine stops twice a year without warning, naturally at the most inopportune time. Then something needs to be done. Most, if not all, 35-year-old diesel tanks have glop in them. The filters can typically handle it in normal sailing. In a gale, or just a day of vigorous sea state, they often can't. A violent sea state agitates the particles and the filter is overwhelmed.

The fix for frequent engine stoppages as result of a clogged filter is to manually clean out the diesel tank. Inspection ports are probably required, and they're not all that hard to install. My report here. I'd say cleaning the tank is necessary before any offshore venture, or if filter clogging is becoming routine. Here's another inspection port video I just happened on.