Dual fuel filters - will it work?

[Enniberg]

Decided to pull out the fuel tanks on my boat (48 gal main tank and two 9 gal saddle tanks) to clean them up. I was horrified to see how much junk and sludge was floating around on the bottom of the tanks and decided to replace pretty much everything - fuel lines (almost 50 feet), filler hoses, filler necks, fuel pickups, anti siphon valves and the 3 way selector valve.

Since the boat only had a Sierra fuel filter, I decided to add a Racor with a see through bowl, so I can better track what is going on.

I ended up just adding the Racor before the Sierra, figuring that 2 filters is better than one - even though they are both rated at the same 10 microns.
Have not had the boat out since and am wondering if any of you guys know if this could do the fuel pump any harm?

My reasoning was that the Sierra is rated at a significantly higher flow rate than the Racor, so having it mounted after the Racor might not cause much restriction?

 

[Plug”N”away]

Just remove the Sierra And don’t worry about it. It is redundant having two ten micron filters in line of each other anyway.

 

[Gong Show]

Or switch first filter to 30 and keep secondary at 10.

 

[Enniberg]

Or switch first filter to 30 and keep secondary at 10.

I know of guys with outboards who use a 2 micron Racor and in the back of my mind, that is what I was thinking to try. I worry less about the benefits of dual filters potentially being questionable and more about possible harm to the fuel pump, so I was hoping someone maybe knew more about how it affects fuel flow.

 

[Rockfish]

I don't see the point in running two filters in line on the same fuel supply line, and each motor will also have its own fuel filter built in on the motor. I do run two Racor filters/water separators, because each motor has its own complete fuel supply system from the tank to each motor including its own Racor. The fuel pumps, especially on main outboards have a lot of suck. I have seen outboard fuel pumps completely collapse a portable plastic fuel tank like a crushed pop can, when the user forgot to open the air intake valve on the tank. I would just check and drain the water separator and replace the filter on a regular schedule. Some have a screen on the bottom of the up tubes in the tank. When we replace the fuel tank we did not bother with the in tank screens as they can clog up rather easily and starve your motor of fuel. We just let the Racor filters with the larger surface area do their job. Our system has been problem free since we replace the tank and fuel supply system other than rare basic maintenance, such as bulb pumps that wear out or a clamp that need some attention to check a small sucking air leak.

 

[Sir Reel]

My diesels have a Racor with 10 micron and then a large sized 2 micron filter on the engines. Tolerances are much higher though.
You could run the same or a 30 and a 10.

 

[wolf]

Only need one and replace every year part of the routine , if you see water in that bowl dump it out right away , also those filter do not like water at all and if they get filled with water might as well replace with a new one,have to ask yourself how your tanks got so dirty in the first place?
Sierra brand is defiantly more then fine as they meet all criteria, ive ran them for years and way cheaper no need to pay racor brand name pricing when you toss them every year, just be mindful to check the bowl and you will be fine .

Good luck Wolf

 

[jim morrow]

How about this idea, to solve that problem of the filter plugging on a long journey.
Put the two filters in line, but then have tubing and valve to bypass the first filter, and use the 2nd filter instead.
the plugging will happen in the first filter inline.

 

[Rockfish]

I think Wolf hit the nail on the head. What is/was wrong with your tank and related systems that your tank/s is/was full of crap? Most fuel docks do a good job filtering fuel, but if you put it in old gas containers first, especially metal ones, before it goes in the boat tanks?? Use a fuel funnel with a screen.
I would be more concerned about water in the system, as that can do more serious expensive damage to injectors etc. Even my rather dated main motor has a very good built in filter and, I believe, a sensor and alarm for water in the motor fuel filter system. If that alarm were to ever go off, I am going back to the dock on the kicker, assuming the computer does not shut the motor down on its own. That should not happen if you are schedule checking and servicing both the motor filter system and the external fuel supply/filter/water separator systems. If anything bad were to get by the Racor's I would expect the motor filter system to deal with it. Easy to forget that the fuel protection systems on the motors also need scheduled checking and filter replacement.

 

[wolf]

How about this idea, to solve that problem of the filter plugging on a long journey.
Put the two filters in line, but then have tubing and valve to bypass the first filter, and use the 2nd filter instead.
the plugging will happen in the first filter inline.

Why bother? really its about doing scheduled yearly or every 6 month due diligence why over complicate something as easy as spinning on a new filter? especially if it has a see thru bowl we slap on a 30 grand motor and just forget about it ...ummm no daily , monthly and yearly duties is what is required to make these run its not hard ... prevention is always better then something happening when ****** water happens and it fails then only one to blame is yourself from lack of doing...

 

[Enniberg]

Thanks for the feedback guys! The Sierra filter has been removed and I am just going to stick with the Racor.

 

[Sharphooks]

Good move removing one of those two fuel water seperators. The word I kept looking for in the above responses of having two in-line filters was the word “risk”.

I have had several incidents in several boats I have owned over the years, both related to fuel/water seprators. There are lots of fittings involved in these seprators, especially the ones with the removable bowls—-brass elbow joints, multiple “O” rings etc....each one of those joining surfaces can suck air. And when they do, you’re dead in the water.

Two in-line = double the risk of that happening

I remember once taking my new-to-me 21 foot Arima out on its maiden voyage. I got out into the middle of the Salish Sea and the Honda 150 just died without warning. Oh, I’ll get home on the Honda 9.9 kicker, I said to myself. I fired it up, then it died, too. For the first time in my boating career I had to get towed back to the dock

Turns out the former owner had over-tightened one of the brass elbow-joints going into the head of the fuel-water seperator...just a hair-line crack that was tough to see but that was enough to kill fuel delivery to both engines

 

[sly_karma]

Hard to avoid some degree of ethanol in fuels these days. Replace fuel lines every 5 years or so. One in hull filter 20 or 30 micron, plus the 10 micron inside motor cowling. Separate filtered fuel supply for kicker or second motor if using twins. Bad fuel is the usual cause for fails in modern outboards.

 

[Enniberg]

Good move removing one of those two fuel water seperators. The word I kept looking for in the above responses of having two in-line filters was the word “risk”.

I have had several incidents in several boats I have owned over the years, both related to fuel/water seprators. There are lots of fittings involved in these seprators, especially the ones with the removable bowls—-brass elbow joints, multiple “O” rings etc....each one of those joining surfaces can suck air. And when they do, you’re dead in the water.

Two in-line = double the risk of that happening

I remember once taking my new-to-me 21 foot Arima out on its maiden voyage. I got out into the middle of the Salish Sea and the Honda 150 just died without warning. Oh, I’ll get home on the Honda 9.9 kicker, I said to myself. I fired it up, then it died, too. For the first time in my boating career I had to get towed back to the dock

Turns out the former owner had over-tightened one of the brass elbow-joints going into the head of the fuel-water seperator...just a hair-line crack that was tough to see but that was enough to kill fuel delivery to both engines

Good point!

One thing that worries me about the Racor is that unlike the Sierra, the filter is difficult to remove, and the see through bowl even more so - not a good thing if it got clogged and needed to be replaced out on the water, especially in rough seas.

 

[Rockfish]

If your metal tank and the components of the external fuel supply system have not past their best before date/reached end of life, and are inspected and properly serviced, water in the system should not be a problem. Sucking air leaks are more likely to be a problem and the more connections you have the more likely that one will go bad and cause a problem with one of the motors. For each motor between the tank connections, the bronze fuel cut off valves, the racors, the bulb pumps and then the motors, there is a lot of external connections and the bulb pumps internal valve also has a life span and can and do fail, more often than I would have thought. If you want to decrease problems stay away from the extremely cheap crap plated, perforated clamps for cars. Even the marine, stainless, non-perforated (don't cut into the fuel line) clamps come in several levels of design, quality and price. We went for the best, but they cost ten times or more than a cheap Can. Tire plated, perforated hose clamp for an auto does. When we replaced our entire system the various clamps alone cost hundreds. The big ones for the filler fuel hose were particularly pricey. If you want to decrease sucking air leaks, high-end marine clamps make a difference.

We get all of our fuel from the fuel dock, which is marine grade fuel (mid-grade in terms of octane) and I understand has no ethanol to degrade the fuel lines. I hope that does not change as the fuel companies face pressure to go green. It seems to me, not having ethanol in marine fuel is a safety factor. If your car motor fails, you just pull over to the side of the road, but you do not have that option on a small boat in the ocean.

 

[Sharphooks]

Good point!

One thing that worries me about the Racor is that unlike the Sierra, the filter is difficult to remove, and the see through bowl even more so - not a good thing if it got clogged and needed to be replaced out on the water, especially in rough seas.

I think Racor filters are a terrible design. Even after lubing the “O” ring at both the top and bottom of the filter, I have had issues removing the filter and I have seen other guys post complaining about the same thing. Strap wrench, filter wrench: doesn’t seem to matter, you can deform the filter both removing and screwing back on. The safest approach in case you get in a panic situation where you have to do a quick replacement: buy a full back-up unit, including both filter and plastic cup: you’ll have more to grip and will get a quicker replacement time. Just remember to prime it before screwing it back in

 

[Rockfish]

I think Racor filters are a terrible design. Even after lubing the “O” ring at both the top and bottom of the filter, I have had issues removing the filter and I have seen other guys post complaining about the same thing. Strap wrench, filter wrench: doesn’t seem to matter, you can deform the filter both removing and screwing back on. The safest approach in case you get in a panic situation where you have to do a quick replacement: buy a full back-up unit, including both filter and plastic cup: you’ll have more to grip and will get a quicker replacement time. Just remember to prime it before screwing it back in

Valid concerns, especially if the filter is not serviced for a considerable period of time. I have not been a big fan of the Racor Aluminium top. I have seen one so corroded once the coating was breached and water got under it that there was a huge amount of the AL eaten away and replaced by white powder to the point it compromised the seal, and was leaking. It probably did not help that it was in the bilge and subject to a lot of salt water from the raw salt water wash down system. Don't know if they make a top section with a stainless version yet, but if they do, I would be willing to pay more for it.

 

[Sharphooks]

On two ocassions I was forced to drill a hole in the filter housing, then insert a screw driver blade to get enough leverage to twist if off. (Yes, I had pre-lubed the “O” rings and mounting hole threads etc) I posted that picture on a large marine webiste and multiple guys chimed in saying they had to do similar work-arounds to remove their stuck/deformed Raycor filters....known problem

 

[Enniberg]

On two ocassions I was forced to drill a hole in the filter housing, then insert a screw driver blade to get enough leverage to twist if off. (Yes, I had pre-lubed the “O” rings and mounting hole threads etc) I posted that picture on a large marine webiste and multiple guys chimed in saying they had to do similar work-arounds to remove their stuck/deformed Raycor filters....known problem

I never had an issue getting the Sierra filter off and really the only reason I wanted the Racor was the see thru bowl to keep and eye on things and being able to drain small amounts of contaminants. Thinking that the boat could possibly be dead in the water because I cannot change the filter makes me wonder if it was worth it.

 

[Sharphooks]

In my experience, the best removal tool is a strap wrench for those racors. It spreads the pressure out a bit . Filter wrenches —-I’ve had them deform the cannister. It seems it’s due to crappy design.....I’m running Suzuki cannisters now....never had that problem during the removal process. BUt, wow, they’re almost twice the price of a Racor or a Sierra

I also once had the threaded portion inside a Racor break loose from the walls of the cannister (while trying to remove the plastic bowl)

That’s when I had to resort to stabbing the cannister with a screw driver to get it removed. I wrote a love-letter to Racor—-this was their response:

QUOTE

We have heard of this issue before, it has nothing to do with the ethanol, we think its caused by the glue we used to hold the thread ring, since we burst test our filters to 100psi over time the bowls just get stuck on the filter and the glue breaks off when you attempt to remove it, the bowls are on pretty tight, if this happens to you contact us we normally will send you a filter and bowl free of charge. Unfortunately we are required, to test our filters to 100psi, in order to meet standards, we are working on a redesign to help solve this issue.
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