Fuel tank cleaning.....

[Allure2sail]

Hi All:
I went through this about 6 years and I'm back with the same problem again. Motor died last week out on Buzzards Bay during a storm front coming through the area. Really had my hands full, 30 knot gusts and around 8 foot waves. These boats are not made for these conditions in New England. Got pretty hairy off of Sakonnet Point and the light house there. Lucky to be still sailing Allure and not collecting the pieces. Fuel in tank was dirty and the I initially thought the filters had clogged even though they were only 10 months old. Took apart the fuel system and removed the tank for cleaning. Last time I went though this the screen at the top of the pickup tube was plugged and now once again it was all clogged up. I thought I had not put it back in the pickup tube last time I had the tank out but I was wrong and it came back to get me a second time. Definitely leaving it out this time, let the two filters do their thing. Once the screen gets coated with crap the lift pump cannot pull the fuel out of the tank in sufficient amount to keep the engine going. I picked up a big Racor filter setup with a vacuum gage on it and I'm going to install it instead of the puny little one that's on there now. The vacuum gage tells you when the lift pump is having to work harder to deliver the fuel. That way you know when something in the fuel delivery system is getting clogged up. Beware.....use the fuel additives and get rid of that screen in the top of the pickup tube. You must take out the screws holding the tank in place. Shut off the fuel valve, disconnect the fuel line and unscrew the fitting and tube. You have to slide the tank slightly to starboard to be able to remove the tube. Once out put a pair of pliers on the tube and unscrew the top fitting with an open end wrench. Once you take the fitting off you will see the screen inside the top end of the tube. Remove it !!
Hope to get the engine running this week.
Bruce
S/V Allure
Swansea, MA

[Shawn]

Bruce,

Can you pull your tank and pressure wash the inside? If you can that will let you know you are starting with a clean slate.

Good luck!

Shawn

[deisher6]

Hey Bruce: 
Went through the entire set of fuel problems 2.5 years ago.  I removed the screen in the pick up tube, pulled the tank and rinsed it out with muratic acid, and mounted the fuel pump as low as I could on the aft bulkhead of the head in the cockpit locker.

I was fooled by thinking if I could blow air into the tank that the pick up tube was clear.  Keith Scott told me about the screen in the top of the pickup tube.  It acts as a one way, wrong way,  valve when fouled.

Since then I have only used diesel that I have purchased at non marine pumps. Always put antibacterial and water additives.

The fuel pump is not very good at sucking, much better at pushing.  There is also a screen in the bottom of the pump you may want to check.

You are absolutely correct the C-27 is not at its best in rising winds and waves especially if you have to beat into it....

Glad to know that Allure is still sailing.

regards charlie

[Tom L.]

I had similar problems with a boat that had a 50 gallon tank. It was a 4 cylinder diesel but we took a long time to burn that much fuel. The diesel would build up sludge due to bio chemistry. It would show up when conditions were rough. Wave action wold stir up the tank and the fuel pick up would get clogged.

I finally cut a large hole n the top of the tank and had a service come in and steam clean the tank and replaced the fuel lines. After that no problems. We either kept the tank as full as possible to reduce the problem with water condensation (especially for winter layup) or with only 15 gallons so we would turn it over more often. But the key was we added Bibor JF. A biocide that stops growth in the tank. Also try to use off road fuel. Higher sulfur content is better for marine diesels. It is particularly important on older engines.

The only time we used over 2 or 3 gallons of fuel on a weekend was on our summer cruises. So the fuel has to be treated. Of course we had raycor filters (2) one course one fine in line. Usually I changed the filters once a season.

Tom L.

[Allure2sail]

Hi Charlie and others....
Rinsed out the fuel tank (which I had removed yesterday) with gasoline and poured it through a coffee filter each time to see what came out. The disgusting looking sludge was a real surprise for me. Always keep the tank full, filtered it when I put diesel in it and always used "lucas fuel" conditioner to keep the injectors clean. I got rid of the screen in the pickup tube and will be installing new primary and secondary filters. Actually going to replace the racor water separator / fuel filter with a big racor 500G I picked up not to long ago. This setup has a vacuum gage on it to tell when it is getting close to filter changing time. These units are cool, you can change the element without putting air in the system, thus no need for bleeding. I have to admit I thought Allure was about to be smashed on the rocks at the Sakonnet lighthouse....scariest sail in thirteen years. Time to get a bigger boat !!! Should be back in action next week.
Bruce
S/V Allure
Swansea, MA

[Allure2sail]

Finishing up....
Got ride of the screen filter at the top of the pickup tube (should have done that a long time ago). Repositioned the tank an inch and a half to starboard so you can pull out pickup tube without un mounting the tank. Put rubber pads under the four corners before screwing it down so it doesn't forever sit on the wooden board which is usually wet. In the end of rinsing out the tank I used a mixture of carburetor cleaner and gasoline for the final rinses. Should be all set now.
Bruce
S/V Allure
Swansea, MA

[deisher6]

Hey Bruce:
100% agree with the pickup screen. 

Using muratic (sp) acid for a tank cleaner really works.  I recall that it is actually dilute HCl. A local, junk yard/marina owner who looked like he might have had a bunch of experience with fouled tanks recommended it to me.  I cautious and apprehensive, but it really was fast and thorough.  Used 1/2 gallon of acid, each for two rinses, flushed thoroughly, and dried with a heat gun after the final rinse.  I did not leave the acid in the tank very long probably less than a minute, just enough time to slosh it over all surfaces a couple of times.  I do not recall the concentration, but it is the standard mix sold at hardware stores for cleaning concrete. 

Thanks for the blog.  Stay safe and enjoy your C-27.

regards charlie

[deisher6]

Hey Bruce:
Great talking with you today. 

I looked up and read my old post on fuel (C27 Fuel Information
« on: February 05, 2014, 10:24:00 PM »)  I am going to the boat today or tomorrow and I will check out the filter arrangement.  I believe that I left it: fuel tank - fuel pump - Racor filter - engine mounted filter. 

I will post again on my final arrangement .  Have not had fuel problems for almost 2 years!

Stay at it!

regards charlie

[deisher6]

I checked how I set up the fuel system.  It is: tank - Racor water separator/filter - fuel pump - fuel filter on engine. 

The fuel pump is the lowest item on the system.  It does push better than pulling.

[BobK]

Bruce,

the black slime you are finding is actually an algae that grows in diesel fuel.  To prevent this (kill it) you need to add a diesel fuel algaecide to your fuel tank each time you add fuel.  The algae is not only in the tank and filters but also in all the fuel lines.  After it is killed it will be trapped in the filter and may clog it again.  Why to carry spare filters.  The algaecide is best purchased in the larger truck stops.  Truckers experience the same problem and use the best products.

I added an outboard fuel squeeze bulb between the fuel tank and the racor filter.  This makes priming much easier and gets fuel to the electric fuel pump so it can do its job.

BobK

[Allure2sail]

Hi Guys:
Got the beast running last evening.....what a struggle. New hoses, filters, fuel and a lot of sweat. Being down there in 95 degree humid days is no fun. As far as the order of things it is tank to Racor water separator, facet lift, filter on engine, injector pump and of course injectors. I kept seeing tiny air bubbles in the bowl of the Racor until I changed all the fuel line and double clamped everything. Must have had a compromised hose before the pump because no mater how many times I would bleed it the engine would not run for more than a few seconds. I would be curious to know if all your fitting and hoses were 1/4 or 5/16. Thing that confused me was the fitting (shut off) on the tank takes 1/4 fuel line but every other fitting in the system is 5/16. I ended up with an adapter stepping it up to 5/16 (was hard to find) near the tank. It is a double ended barb with 1/4 on one end and 5/16 on the other (looks so mickey mouse). Went around tightening clamps a few times to make sure no air could ever get in again. Plan on adding a primer bulb that you mentioned in the near future. I now use the algae killer and Lucas injector cleaner at every fuel stop. Hope this is the end of it. Does anyone know where to get a shut off for the tank that is setup for 5/16 line? Every time I see that fuel line adapter I curse at it !!! Hopping the rest of the season goes well.
P.S. Moyer Marine mentioned that the Coast Guard regulations do not let you put the pump before the Racor separator, anyone familiar with that regulation? Anyone have mismatched hoses in their fuel systems? The secondary problem was the 1/4 line that had been forced onto the 5/16 fitting on the Racor and had started to split. Also could not figure out what kind of fitting are on the Racor the threaded end looks different than anything I've seen, it actually come apart and there is an o'ring that's part of it
Bruce
S/V Allure

[Shawn]

Depends upon which Racor you have. If it is a current production 500 series (very common in boats) it would be a SAE fitting. Older ones (pre'96) apparently used something else.

https://www.fittingsforracor.com/default.asp

"P.S. Moyer Marine mentioned that the Coast Guard regulations do not let you put the pump before the Racor separator, anyone familiar with that regulation? "

That might have to do with the pump being within 12"s of the the engine. USCG wants as little pressurized fuel line as possible. The regulations vary a bit between diesel and gas though so Moyer may be talking about a gasoline specific regulation. Racors are meant to be on the suction side of a pump anyway.

Shawn