Small Surges in RPM Every Few Minutes.

[Marin]

GonzoF1 wrote:

When we got to the boat this time after being away for a month, I found an inch or more of sediment in the bowls of the Racors.

I am curious if someone can provide an answer to this--- how would an inch of sediment build up in the bowl of a Racor (or any filter) over the course of a month during which no fuel was flowing through them since the boat was not run?

We have Racors in the fuel lines of our engines and generator.* While we never let more than a month or so go by without at least running the engines under load at temperature even if we don't take the boat out, the generator will sometimes go unused for a couple of months depending on what we're doing with the boat.* But in eight years or so we've had the Racors in the fuel system, we have never gotten any residue or water in the bowls.

So I would be very interested to know how the fuel sitting in a Racor could precipitate out an inch of sediment in the course of just a month.* Or any length of time, for that matter.

I'm not challenging Gonzo's statement, I'm just curious what could cause this to happen.

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[Tom.B]

... And I thought the same thing. It had to form stagnant because the genset had some in it as well. It wasn't just the main filter, it was both of them.

 

[Larry M]

GonzoF1 wrote:

... And I thought the same thing. It had to form stagnant because the genset had some in it as well. It wasn't just the main filter, it was both of them.

The sediment was probably there from the last time you ran the engine and generator and it wasn't plainly visible?* Regardless, fuel and fuel tanks seem to be at issue.*

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[jleonard]

GonzoF1 wrote:

What kind of pump is that (lower left corner) and how long/often did you run it?

It's a Walbro pump, low gph, and I had slightly less than half tanks. Filtered starboard to port, then port back to starboard, then I let the tanks equalize. The pump ran several hours over 2 days I don't remember exactly.

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[Tom.B]

jleonard wrote:

I borrowed a friend's portable filtering setup when I first bought my Albin. I filtered from one tank into the other and when that tank was empty I inspected thru a hatch and there was no visable crud to speak of...also ran the intake hose and fitting under the baffles and as far as I could tell there wasn't any gunk buildup.
Then I filtered back into the original tank and did the same type of inspection.

After filtering approx 300 gallons of fuel the filters did not look dirty to me. I expected crud but they were pretty clean.

Can I assume that the reason for the Gulf Coast filter was for doing the heavy lifting of the filtering work and the Racor 900 was used because of the clear bowl allowing for the monitoring of your progress?

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[Phil Fill]

We have come full circle as fuel polishing and additives was mentioned on the first 2 pages, which was put down?*

I been using the same Welbro fuel pump for 12+ years, 40+ hours/year.* The pump is rate around 50 gallons/hour, its self priming, and can run dry.* Make sure the filters are before the pump to protect it.**




To fix the small Webasto air leak I wired the Welbro pump to the Webasto so*when the Webasto turns on so does the pump.* It was*an easy fix as the fuel can be drawn returned to either of the three tanks and feed the 671, gen set and/or Webasto.* If you do not have fuel polishing system with a fuel pump you*might want to.

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[Tom.B]

I don't see where a fuel polish was shot down, Phil. However, let's try and be clear before you take it personally. Early in the thread, I was still learning about the problem of the surges, I was trying to narrow the problem down, and more importantly... I wanted to try the simplest and cheapest things first.

So on behalf of the thread "owner"... Me

...I apologize if you felt shot down, but I certainly was now a party to it. We all try to help each other out and in a 13-page thread, we might cover the same thing twice. Nature of the beast, I suppose.

Over the course of this wonderful thread, I have learned an enormous amount about my fuel system - a system that I was a little afraid to dig into because of the dreaded air bubble, but this past weekend I just dug right in and felt cofident in what I was doing. Now, it appears that I need to do a few things that I didn't know before or more accurately, have learned in 13 pages of advice and links. Primarily, I need to upgrade the fuel filtration system in a big way. It's a mish-mash of rotary faucet valves on the tanks, a combination of both hard and soft lines, and an Algae Magnet that all need attention. In doing so, I need to rig it to have a fuel transfer and scrubbing system added from either a portable system or permanently mounted one.

Now... Tell me what this means: "To fix the small Webasto air leak..." I'm not sure what you are talking about there. Also, what model Welbro are you using and do you have a pic of your rig?

So, I sat down with pencil and paper tonight to try and design a system. It's WAY harder than I thought it would be. Every system I design ends up with about 10 two or three-way ball valves. I'd be afraid of getting one of the settings wrong in the attempt to get them all set right for whatever job I need done. I guess I need to keep trying.

Tom-



-- Edited by GonzoF1 on Wednesday 5th of January 2011 11:27:39 PM

 

[Marin]

I don't know much about fuel systems. The one the previous owner installed on our boat is relatively simple although it has some ways to screw up (as I discovered by letting an engine die from getting a slug of air during a fuel transfer).

But I think I've learned a couple of things along the way.

1. Keep the fuel system as simple as possible with the fewest number of components that will do the job you need them to do. The more components, valves, etc. there are, the more chances for air and fuel leaks there will be.

2. Our system incorporates a fuel transfer pump. It can be used to move fuel from one tank to another through a Racor filter and it can also pump fuel off the boat should we pick up a load of bad fuel. Other than making sure it worked when we bought the boat we have never used it in the twelve years since. But recently I've been thinking it might be a good idea to make sure it still works and I've been assuming that the pump impeller would need to be replaced before running it. I had been assuming it was a flexible impeller pump and that the fuel sitting in it would have long ago rendered the impeller unusable. But in looking in the manual for the pump it turns out it's a vane pump. I'm assuming the vanes in a pump like this are immune to fuel over time. Anyway, I learned that impeller pumps are not created equal and there are different types for different uses. Seems obvious but you never know.....

3. Don't skimp on whatever components you get. The best quality hose, the best quality valves, the best quality connectors will make their additional cost worth it in the long run.

-- Edited by Marin on Wednesday 5th of January 2011 11:45:51 PM

 

[jleonard]

"Can I assume that the reason for the Gulf Coast filter was for doing the heavy lifting of the filtering work and the Racor 900 was used because of the clear bowl allowing for the monitoring of your progress?"

I borrowed the rig as is and used it without modifying anything. I really don't know what his theory was. Neither filter looked like it was dirty after filering all my fuel.

 

[Phil Fill]

*
Hiya,
** No Phil/Fill you won't be able to see bubbles in the Racor bowl.* Stick to what you KNOW-manicures and dresses!
** Mr. Gonzo take note of the question marks Phil/Fill puts after his statements-as USUAL, he hasn't got a clue.* Ignore his advice.
** The suggestions made by the other listees are all valid and again, fuel systems are pretty simple so the solution should be simple as well.*
*
You were not a party but comments were made. **I appreciate your comments.**The TF site is supposed to be monitored so flaming and people are civil?* *
*
I have a diagram I can send you if you send me your email address. A fuel polishing system is comprised of primary filters, electric fuel pump, three manifolds (intake, distribution and return) which can be made from copper pipe fittings and valves. I have used the in line clear filter before on a temporary bases to see the air leak as things were changed tightened. The air leak was reduced by 50% which does not shut down the Webasto.* Using the electric fuel pump I can pressurize the fuel lines enough to stop the air leak, but it would have been nice to have found and fixed it.*
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Over the 15 years I have tracked down and fix several air leaks as they can develop over time.* My experience and verified by my diesel mechanics is if the filter is filled with air then the leak is probable at the filter or before.* So next time when you check/change your filter take note of the fuel level.* Then install the clear in line before or after the filter, so you can see it as you make changes and tighten things.
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Send me your email address and I will send you a diagram and my phone number.**


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