Dirty Fuel

A few months ago I had a problem getting my starboard engine above 1500 RPM's and discovered the fuel filter was clogged. This was the Racor pre filter a 10 micron. So I put on a 30 micron on both raycor's and installed a Vacuum gauge on the starboard side thinking it was the bad side. I also added a Diesel Kleen to treat 300 gallons. I used the boat and no issues and the vacuum gauges on the starboard side is still green.

My plan was to run the boat for about 20 hours and then change all filters, and go back to a 10 on the pre filters so I only have to change them rather than the engine filters.

Friday when taking off the raycor on the Port side it was so bad that I was surprised the boat was running so well. The engine filters are hard to see but had some sediment in them as well. This was my first engine fuel filter change ever (new boat to me).

I have about 100 gallons left in each tank. My engines are Lehman 135's and the hours are low 1550 and 1650 but the boat was used frequently so I am told by my dock neighbors.

My questions are 1. will a raycor 30 micron last 3 times as long as a raycor 10 micron? 2. What are the chances the fuel is contaminated but the tanks are ok?
Has anyone had luck cleaning the fuel and not the tanks? They are original tanks fully wrapped in fiberglass. The price to do access hatches and fuel polishing was 2700.00.

My plan now is to do the starboard side with the new Raycor 10 micron and new engine filters. Clean both sediment bowls and flush. Check the fuel coming out of the tanks and if its ok leave it and keep changing pre filters and if it looks bad then drain all but 20 gallons or so from each tank take it to my house and set up a polisher or dispose of it.

I do not understand why you would increase the micron rating to 30 when you have a known fuel contamination issue. All you did was move the problem down stream to the on-engine filters - the last line of defense. To answer your question about filter longevity, a 30 micron will surely "last" longer but only because it is letting crap go through to your on-engine filter. So, not a good solution! Is this old fuel that came with a boat just purchased? If, as indicated, the boat was used frequently, when was the fuel acquired - how old is it? What would cause the problem to suddenly occur? Was the sea particularly rough - did it really stir things up? Whatever the cause, you really do not know the extent of the issue, so I would begin with just polishing the fuel, before spending to install access ports. You might consider doing yourself on board by installing a Gulfstream (example only) filter with a recirculating pump circuit. Another solution is to simply buy a case of 10 micron filters and keep changing them till the problem hopefully goes away.

The boat came with little recent history but the Engine filters appeared to be relatively new by looking at their exteriors but I planned on changing them soon. I had to move the boat a distance prior to changing all filters and going to the 30's would allow this. I added about 75 gallons of fuel to the boat since I owned it but there is no way of telling how old the fuel is that is on board the boat holds some 400 gallons and was 3/4 full when I purchased it. Now a year later each tank is about 1/2 full. Each trip out has produced a lot of rocking and some pretty heavy seas and Navy wakes. The problem isn't really new, I have only had the boat for a year and use it about once a month so it's what I would say is on going problem and I realize more analysis is needed on my end but wanted to know if anyone has had luck cleaning the fuel and not the tanks since I know that is an issue or when the fuel has a lot of sediments is it normally tank related? I also wondered if the 30 micron filter would clog 3 times slower than a 10 so I get an idea of how often I will have to change the 10's.

I guess I can't totally agree with Chrisjs .Pretty much the standard is 30's in the raycors and 10's in the secondary. I would be concerned about the tanks. What year are they. When you say they are fully wrapped in fiberglass what exactly does that mean ? Are they steel insulated in glass or of fiberglass construction?

My first step would be to get the fuel polished. If that requires you to pay the $2700 for access ports I guess it must be done.

My tanks have been redone and the fuel samples are pristine. It really gives me confidence when I am out on a bouncy ride knowing there is nothing to stir up and plog filters.

pete

Another temporary solution might be to just install a prefilter between the tanks and the racor. While this worked fine on my Cummins, using the Gulfstream routinely as a prefilter without the recirc pump operational, not sure whether Lehmans provide enough suction to draw fuel through both a prefilter and 2 in-line Racors. Installing a fuel polishing filter arrangement (with pump) will provide you a longer term solution, at reasonable cost.

Not enough info here. Did you add a biocide with the 75 gallons? Possibly you are cleaning a life time of sludge out of the tanks. I once bought 100’ of fuel line and a transfer pump. I found a spot after the Raycor to tap into and emptied tank 1 in to tank 2, then reversed the process, all with a heavy dose of biocide. Cleaned a pint of sludge out of each raycor bowl and went through 4 filters, she’s been clean ever since.

The key was pumping each tank dry to get all the sludge out. Did the process several times until my filters looked clean after both tanks had passed through.

How was the boat used before you got it? If you can't get a reliable read on past usage, assume that it sat for quite awhile both before and while on the market, as many do.
Put some Biobor in the tanks, stock up on filter elements for both the Racor primaries and the engine mounted secondaries. Use the boat. Change filters as needed, if frequent, and regularly if not needed frequently.
Unless you are fueling way off the beaten track, your refill fuel will be clean. EPA requirements for low sulphur content mandate the refineries delivering clean fuel, so the only contaminants you will have are already growing in your tanks. Biobor should kill the organics, filters will clear the crap as the fuel passes through your filters.
Unless you pay extra for a thorough tank cleaning, polishing will do no more than just running your engines, though it will process the fuel faster.

I would go back to the 10 micron elements. You want to catch as much crap as possible and you want to catch it in the Racors because they are easy to change. Stock up on 10 micron elements. Run the boat and keep changing elements as needed. If the problem persists then have the tanks cleaned.

Thanks for all of the useful information. The tanks are totally what appears to be wrapped in fiberglass but may indeed be fiberglass? The boat is a 1985. With only 1550 and 1650 approximate hours yes it's sat for a while I am sure but I was told by dock neighbors it was frequently used the past few years, probably just short trips I would guess.

With a boat that holds 400 gallons of fuel and only uses 4gph I would think there is a lot of old fuel in the tanks unless the boat is used weekly which isn't the case.

I didn't use a biocide I used a product called Clear Diesel which is a fuel and tank cleaner.
So I'll add a biocide now and use 10 micron filters and install another vacuum gauge so I have one on each raycore and change filter every time the vacuum gauge indicates it's necessary.

In my opinion it would be a bit unusual for a Marine Trader of that vintage to have fiberglass tanks, but its certainly possible depending on the yard it was built in or possibly a previous owner installing them.

If your tanks are indeed dirty (and it sounds like they are) no additive is going to remove the "dirt". You didn't say but implied that you do not have access to look inside the tank? I would hope there is at least access to the fuel senders? If so, you can remove those to look inside with a strong flashlight.

If you even think you have old and possibly dirty fuel then you probably do. Fuel can be cleaned up either by a fuel polishing "service" or by simply using as much as possible and probably changing filters more often. On thing is for sure, dirt in the tank is not going to remove itself no matter what you pour in. A bigger deal is if you have water in the tanks. Looking inside with the tank level very low or draining out some fuel from the very bottom can tell you this. Do you have a crossover pipe connecting the very bottom of the tanks together? If you do, you could use that to get a sample from the lowest point of the tank.

By the way I completely agree with Chrisjs that installing 30 micron filters just shiftss more of the filtering chores to the on-engine filters which are indeed your last defense.

Ken

My 120 Lehman has no trouble pulling thru 2 Racor filters.
This is my set up that cleaned my fuel when I bought the boat. Haven't
had a problem since.
Filter on left is a Racor 900 with a 30 micron element. Next is the Racor 500s with 10 micron, then it goes to the on engine filters.
Lots of ways to deal with your problem, this is one that worked for me and is still on duty.

ps the electric pump is plumbed in in case I needed to "polish" my fuel but I never needed to.

I use a 10 micron in my Racors since it is much easier to change than the on engine filters. I am changing my Racor 900FGs to 900MAs, one this winter and one next winter. While I am changing them I am adding the Racor priming pump to each 900. The Racors will gravity prime if the tanks are about half full or more but the CAV filters on the engine are a PITA to bleed hence the Racor priming pump. I have never had a problem using the 10 microns in the Racors and my CAV on engine filters last a long time. I would much rather have the crap picked up in the Racors than the CAVs.

koliver said:

How was the boat used before you got it? If you can't get a reliable read on past usage, assume that it sat for quite awhile both before and while on the market, as many do.
Put some Biobor in the tanks, stock up on filter elements for both the Racor primaries and the engine mounted secondaries. Use the boat. Change filters as needed, if frequent, and regularly if not needed frequently.
Unless you are fueling way off the beaten track, your refill fuel will be clean. EPA requirements for low sulphur content mandate the refineries delivering clean fuel, so the only contaminants you will have are already growing in your tanks. Biobor should kill the organics, filters will clear the crap as the fuel passes through your filters.
Unless you pay extra for a thorough tank cleaning, polishing will do no more than just running your engines, though it will process the fuel faster.

Click to expand...

Derik
Precisely what I would do. To go a step further follow Jay's advice and hook it up as per post 11. You'll never look back.

For additional knowledge go to seaboard's site and read Tony's tips on fuel filtering. Don't get caught up on filter micron size, just change what you have frequently until fuel clean.

DIY fuel polishing.
Get an electric fuel pump and plumb it from one tanks outlet to the intake side of the Racor. Run a line from the Racor outlet to the fuel return on top of the tank. Let it run.
Run until the filter stays reasonably clean. Other tank same thing.

No hard and fast rules here. Barb fittings and rubber fuel hose should be OK.
Change filter as needed and keep the batteries charged. I wouldn't leave it run while I was away...

HEAVY Crud collects on the outside of the filter , it doesn't get inside.

I would pull the tank feed and install an electric pump to SUCK thru any OK brand of filter. A 10 or a 2 would work fine.

This will clean the fuel, but not the gunk stuck on the surfaces of the tank.

So repeat the filtering process after every run in heavy weather.

If you ran a couple hundred gallons through the racor's, they were not recently changed, and only one event of clogging, and you have been running in seas where tanks slosh... I don't think you have a bad problem in the tanks. Problem tanks will clog racors in a matter of hours.

Also, once you get a clogging event, don't just change one racor. Change them for both engines.

Since boat is new to you and you don't know when secondaries were changed, go ahead and change them now.

Another recommendation is to change the racors, then run engines for a while, then change secondaries. Each time you change a racor, there is a "puff" of crud that goes through and will be caught in the sec's. A good practice is after about four changes of racors (forced or not), change the sec's.

Since you ran nearly a whole season with only one clogging event, and you don't know how long the elements were in there, I don't think you need to polish the tanks or re-design the filtration system.

I don't think there is really much difference in using 2, 10, or 30 micron. The 2's in my experience did clog a bit faster, and when changed did not look heavily fouled. I switched back to 10's or 30's, depending on what extras I had on the shelf in the shop. No real difference noted in how long they seem to last before restricting.

Also note that the crud typical in the tanks is slimy bio goo, which is not particularly abrasive. Can probably go right through an injection system with little harm. It's not like our tanks are loaded with silicon carbide grinding dust or finely ground steel dust.

I tend not to get too excited about super elaborate filtration system designs. The standard racor primary and on engine secondary does the job just fine.

If you can only run offshore a matter of hours between clogging events, then you have a problem. But often in that case once you do a few changes, the interval gets longer and longer. The problem then is solving itself. The tanks are cleaning themselves. How clean is debatable, but note also that some dockside tank polishing is debatable too in its effectiveness.

I do like the dual switchable racor's, but I was too cheap to install that on my ride. That's the only feature I might consider adding.

Be careful with adding additives. Some contain alcohol with emulsifies water and end up fouling the whole fuel load. Best to get the water out mechanically and leave the fuel alone. A biocide is always good though. I can't see any other additives being very effective at cleaning dirty tanks.

Keep the tanks low on fuel so that the junk is filtered faster. Adding fuel just dilutes the junk and requires more use to clean it

More good advice. I'll be at the boat tomorrow and post the exact hours of filter changes I have done and hours put on engines since I bought it.

Ok I made it down to the boat today and checked the log. During the engine survey a little over a year ago the broker had the mechanic change the raycor filters but since Raycor was moving their distribution center or something they had only 2 micron filters available. Tanks were about 3/4 full.

I added another 75 gallons of fuel after about the first 8 hours of operation.

24 engine hours later no issues i changed the 2 micron filters to 10 micron filters.

13 engine hours later I had a some rough seas and had the stbd engine not be able to go above 1500 RPMS. I then went to two 30 micron filters.


24 engine hours later I had no issues but decided to change all filters Raycor and Engine filters.
Raycor on Port side looked very clogged. Almost all of these 24 hours were ocean running meaning not too much time in the bay. The first

I haven't added any fuel since the first 8 hours I had the boat. I now have about half a tank in each roughly 125 gallons each tank.

Derik,can you get plastic tubing through the filler to the bottom of the tank and use a little hand pump to suck up what`s there until it pumps out clean fuel? You can zip tie the tube which doesn`t have to be any great diameter, to a wood dowel or a flat strip of metal, positioning the end of the tube just above the end of the dowel.You might be surprised what you draw up.

I believe so, I saw a you tube video where someone did it with a small diameter PVC pipe.

I wanted to get the fuel level down a bit and try to clean the tanks that way, I realize they are baffled so I will be limited but maybe I can reduce some of the goop if there is any.

Copper tube is handy for lancing the bottom of tanks. It holds its shape and can be bent if needed. 3/8" is a decent size to work with.

Derik - Mr. Nigel Calder would also recommend you install an H2Out Fuel Guard Air Vent dryer in your tank's vent line. It won't help with what you're dealing with now, but it will greatly help to keep your fuel clean moving forward.

https://youtu.be/dkji9Ih2ddc

A proper fuel additive will slowly dissolve deposits in fuel tanks. Then the filter catches it. It will also make it easier for the Racor to separate out water.
You can do your own fuel polishing with a pump installed after the Racor that returns to the tank with the addition of tee in the lines. The pump can be run when the engines are running or not. It should pump about 50 gallons an hour. I'd use a 2 micron in the Racor and keep an eye on the vacuum gauge.
I run 2 micron elements in my Racors all the time. I use Archoil AR6200 every fueling. Available on Amazon, eBay or direct archoil.com
I never have fuel problems.

OK quick question. I've always heard an electric inline fuel pump is better at pushing fuel than sucking it. In other words connect the pump close to the tank outlet and push fuel thru the filters and then back to the tank.
Some are saying to put it after the filter..
Only experience I have was with changing to a fuel injection setup on a small block Chevy motor and mounted it right after the tank and to the filter...

Solly said:

OK quick question. I've always heard an electric inline fuel pump is better at pushing fuel than sucking it. In other words connect the pump close to the tank outlet and push fuel thru the filters and then back to the tank.
Some are saying to put it after the filter..
Only experience I have was with changing to a fuel injection setup on a small block Chevy motor and mounted it right after the tank and to the filter...

Click to expand...

I understand your reasoning but I disagree with it. THe fuel pump in push mode can force water through a filter that would never pass in suck mode.
THe pump can emulsify the water into the fuel allowing it to pass.

That can kill your engine plus do some serious damage to the injection system. Injection systems do not like water and water getting into a common rail system is even worse.

On Lehman engines the fuel pump is before the on-engine filters. Yes, most will also have a pre-filter but that was not a design feature of the engine itself. Perhaps there is a big difference between what a 7psi Walbro will do and a common rail pump.

C lectric said:

I understand your reasoning but I disagree with it. THe fuel pump in push mode can force water through a filter that would never pass in suck mode.
THe pump can emulsify the water into the fuel allowing it to pass.

That can kill your engine plus do some serious damage to the injection system. Injection systems do not like water and water getting into a common rail system is even worse.

Click to expand...

Derik, as mentioned before you need to and can easily add an onboard polishing system. Gunk in those old tanks will be a constant in your life, and having a way to deal with it yourself with a polisher just makes sense. I would suggest taking a look at the Gulf Coast filter which can use a roll of toilet paper or paper towels, depending on the filter body you buy. They will filter to .047 microns and are quite cheap compared to the Racor elements. I used to run my Walbro pump polishing each of my trawler's four tanks in turn for about 24 hours once a month while watching the polishing system vacuum gauge - it was a 1972 trawler with Lehman 120s which return very little fuel. I ran 2-micron elements in my Racor 500s because my fuel was so clean after polishing, and I therefore changed the engine-mounted filters at five year or longer intervals after that. My boat has a diesel which runs 20 gallons an hour through my 2-micron Racors (actually burning only 8 or so GPH) keeping my fuel very clean and frequently refilled with new, so no need for a polisher. Keep your tanks as low as practical unless planning a long trip to avoid long term storage and ignore people who would warn you about the myth of condensation collecting in your tanks. Water gets into boat tanks via water from the seller (ask to check their pump clear filter bowls), from leaking o-rings in deck fills where water can collect over them, and from rotted tank tops, not condensation.

Jay,

I’m confused about the picture of your filter system.

You have the coveted twin racors, but have a single 900? In-line before them.

Doesn’t this negate the beauty of the dual system? If you for some unknown reason get bad fuel, and it clogs your first filter (the 900), that will handcuff you and you will have to change filters before proceeding, whereas if you just had the twins, easily switchable with one valve to a fresh filter, you could just switch, move on, and change the filter when more convenient.

Am I missing something?

Dan

BruceK said:

Derik,can you get plastic tubing through the filler to the bottom of the tank and use a little hand pump to suck up what`s there until it pumps out clean fuel? You can zip tie the tube which doesn`t have to be any great diameter, to a wood dowel or a flat strip of metal, positioning the end of the tube just above the end of the dowel.You might be surprised what you draw up.

Click to expand...

Good call Bruce, this concept is really handy anywhere on a boat attached to the hand pressurised/operated engine oil extraction pumps, the wooden dowel holding straight the plastic tubing that naturally wants to bend, drawing water/oil out of hard to get to bilge spaces.