Finally got to change fuel filters underway

[Jim Seamans]

Joan and I had a great four day sail over Labor Day weekend. Got to raft up with some friends and laughed ourselves silly. Went to Solomons on Patuxent River and to Dry Dock for some fine food.

BUT. On Friday as we sailed down the Potomac, we were getting pounded with waves and wind on our nose (so what else is new). As we were motor/sailing the engine started acting up, so I checked the see-thru bowl on the bottom of the primary Racor. It looked murky. We pulled into Tall Timbers, which is off the Potomac and dropped anchor. Took out a gallon jug, cut the top off and drained the Racor. Some nasty stuff came out and then got the filter off. Not good, a very nasty filter. After installing the new filter and purging the air, we started the motor and ran the rpm upto 2500 for about five minutes, where I declared us ready to continue the trip. Well that lasted about 30 minutes. Engine started dropping rpm again and Joan was seeing smoke from the exhaust. OH GREAT. now I have to change the secondary 10micron filter. Glad I had another one on board. So here we are out in the pitching water while I get to change this filter. It came out cruddy also, of course Joan was giving me grief why I didn't change that when I did the other..
After checking the logs it had been a year since I had changed the filters - Can't let that go so long again. It's no fun standing on your head in a pitching boat changing filters. Now I need to rig up a polishing system to remove whatever is alive/dead in the tank.

Jim
S/V Java

 

[Maine Sail]

Jim...

It's quite possible that it was the secondary filter that had clogged to begin with. Most all marine based Yanmar's use a 3 micron "factory" or secondary filter. If you were using say a 30 micron primary then the secondary 3 micron will clog rather fast. My Westerbeke also uses a 3 micron "factory" filter and I use a 10 micron in my Racor 500. Since I switched to a 10 micron primary from a 30 my secondary hardly even changes color from the original yellow paper. On my boat it's much easier to change the Racor than the engine mounted filter though I still do both every spring and before long trips..

Here's a link that describes the secondary Yanmar filters:

 

[Jim Seamans]

Thats a good thought.

Hadn't thought of it in that order. One of the driving things was the 3 micron, I didn't have a o-ring and was afraid of damaging it. I was hopping to get to marina in Solomon's who had the parts. First shot after changing it I didn't seat it properly and leaked about a pint of diesel into the pan under the motor. It was fun cleaning that mess up.
I think I have a couple of 30micron filters left and will change to a smaller when it is time to re-order.

For now, it will be touch and go until I can polish the tank....

Thanks
Jim

 

[Shippy]

30 micron vs 10 micron

hey Jim, sorry to hear about your untimely repair job, but sounds like you came out of it ok...tell Joan we said hi.

I don't want to restart the debate of which size filters to use but be careful when making this change. I took that mack boring class last winter and they were very clear that a lower than 30 micron was not recommended for the primary filter. said it was too hard on the fuel lift pump and will lead to a premature death of that pump. You will hear others say they have been doing it that way for decades and never a problem, and that is true....just relating what Yanmar is stating about our engines and what sthey say the pump was designed for. enjoy T

 

[Maine Sail]

I find it odd

that Yanmar would not build a lift pump that could handle a 10 micron as their secondary filters are 3 micron? 30 to 3 is a big jump.

I've run 10 mic primaries on both power and sail boats for years with never an issue. My current boat came with a stock pile of spares including about five 30 micron primaries. I used them and guess what it plugged my secondary well before the 30 mic primary was plugged. Switched to a 10 and no problems but maybe Westerbeke has a more robust "Prestolite" (that's what mine says under the Weterbeke label) lift pump???

Don't get me wrong a 30 mic is fine but just know that when you plug up it may not be the primary but rather the 3 micron secondary that is choked..

 

[sailaway78]

Lets start the debate again

What I have is, IMHO, about as good as it gets. Can't take the credit for installing them, but what the hey. First they are not Racors. I have two very large Wix filters as primaries. The first is a 30 micron, water separator. Second is a 10 micron. Then of course the standard Yanmar secondary. The only disadvantage I can see with this setup, is the Wix filters do not have a bowl on the bottom that you can visually see water in. Do have a drain plug on the bottom of each. One big advantage is price. I can replace both elements for much less than a single Racor. The local NAPA store keeps them in stock. Another advantage is the size. These things are double the size of the Racors. They are certainly made for something that uses way more fuel than a little 1/2 gallon per hour boat diesel.

 

[Maine Sail]

30/10/3

Now that's filtration!! I wish they just made a 15 or 20 then this would be so much easier. A 30 plugs my secondary but a 10 primary can plug faster than a 30...

 

[Steve Dion]

Don't think you need to change filters more often.

Jim:

The scheduled change on the fuel filters is something like 250 hours.

I really think you need to think about cleaning your tank and the fuel in it. If you are purchasing fuel from a "reputable" source you should be getting fairly clean fuel and may need to think about finding out why your fuel should be this dirty on a "relatively" new boat.

I have thought about building my own fuel polishing system to clean the fuel on a regular basis. The real problem is getting the crud out of the tank so when you are pounding around there is nothing to show up in our filters.

If I were you I would also consider a pre-filter system like the ones that WM sells to remove crud & water from new fuel that you are adding to the tank.

If you fuel is clean the filters on your system are only used to finish off the fuel. One of the guys in our marina did not change his filter for 7-8 years. The only reason he did it was because he thought it was time! Our marina has above ground tanks and they have filters on the fuel that is pumped into our tanks too.

 

[sailaway78]

10 Micron

Mainesail,
I have never had a lift pump problem using a 10 micron in front of the stock Yanmar secondary. Possible because it's so large, but never the less, have never had a problem with it. Since the Yanmar filter is behind the lift pump, maybe it has something to do with suction vs pressure, but as I stated, have never had a problem. And I have never had the little Yanmar filter come out looking anything but like new. I do change it once a year regardless, and not going to change, as I don't like tempting fate.

 

[Don S/V ILLusion]

Think Steve got it right!

It's really all about the fuel quality. If you have good, clean fuel in a clean tank, the debate regardign filter size is largely academic. If you have poor quality or contaminated fuel, the filter(s) regardless of size, are always going to be problematic.

 

[RichH]

Problem with fuel filter 'ratings'

all these 'ratings' are entirely 'arbitrary' and in most cases DO NOT reflect the size particle retained by the filter !!!! In the 'filter industry' these are called NOMINAL ratings and what is missing for the 'consumer' is the efficiency of removal versus the 'rating'.
These filters are very 'inaccurate' visavis the retention rating.

For example a 3µM nominally rated filter would probably approach 15-25µM at 100% reduction. Nominally rated filters will vary 'all over the map' of particle removal efficiency ... from 80% upwards to 97% removal efficiency. The final manufacturer (most dont make the filter media but buy it from a separate source) selects the efficiency and the rating
Many sources would suggest that the 'most damaging' particle in a fuel system would be ~20µM

If your system was correctly sized then when you have a problem, ALL the successive 'stages' all FAIL/CHOKE SIMULTANEOUSLY. .... not a single stage failing by itself. Each 'prefilter' is there solely to extend the service life of the immediate 'downstream' filter... only. This will give you the longest service life of the 'set'. Ultimately, You 'balance' the system by the 'surface areas' so that all filters 'complete' at the same time.

Filters will only remove what is sent to them. The original poster most probably has a tank that is long overdue for a thorough cleaning to remove the 'resins', etc. that have been attached by the fungals and bacteria that form them and use the fuel as a nutrient source.

Clean out your tank (walls) on a regular basis, keep the water out the tank, dont overload the tank with fuel that will degrade upon long term storage - these particles grow/agglomerate inside the tank, buy 'fresh' fuel (not the stuff thats been sitting for years in a 'marina' tank.), drain/empty the tank for winter or long term storage .... and you wont be 'challenging' the filters with debris. Changing filters is not a substitute for fuel system / tank maintenance !!!!!!!!