Bad fuel

[Randomwake]

I have a 34CHB and have a persistent problem since water got into fuel 2 years ago. I used an oil pump and tried to get right to the bottom of the angled tank. I thought I got it all and it ran good at the end of the season last year. This year when I put the boat in the water the sight glass got a really dark hue. And the fuel filter plugged up again.

Does anyone have an idea of how to resolve this issue once and for all. The access to these fuel tanks is horrible!

There’s a company in town that cleans fuel tanks but it’s a major and costs thousands. Looking for a layman’s fix.

Thanks!

 

[psneeld]

Water causes a lot of bacterial growth (often confused with algae), and in your situation.... could be the bottom of the tank has been overcome with this sludge.

Mine was and I didn't know it till I removed the original tanks of nearly 25 years.

Consider the use of a pro cleaner and they probably will solve your problem, but no guarantees.

A large cleaning port is the only solution whether you clean or a pro.

 

[O C Diver]

I would look at the tank with a carpenter's level to determine if there's a low point to where the fuel is moving. It's important to understand where the water is going as opposed to where you think it's going.

If you find that you can't reach that corner, then determine the easiest corner to reach. I've never done the following, but it should work well. After having determined the optimal corner, pick the boat up with a travel lift. Obviously you could elevate the bow or stern by elevating the forward of rear sling. By moving the boat in the water towards one side or the other of the travel lift, when the sling picks the boat out of the water, the boat will lean. I would imagine that maybe 20 or 30 degrees of list would be as much as you could attain. Depending on the yard, you might be able to leave the boat partly in the water and remove the water in the fuel tank. Alternatively, have the boat blocked bow or stern high with the slings of the travel lift from keeping the boat from rolling. For me, I rather keep the boat in the water to be able to rock it and have water moving towards the lowest point.

Ted

 

[Mac2]

How did water get in the tank two years ago and did you resolve that issue?

 

[Iggy]

Thats sucks! I had black junk in my tanks when I bought it. I polished the fuel, but got almost nothing in the filters. What I found out, the tank needs to be agitated. I set up the polisher at the slip and turned it on. Than walked from port to starboard and back. That did work, not great but better.

 

[SteveK]

JF Diesel Fuel Additive: Highly Effective Fuel Biocide Supplement, Prevents Corrosion of Fuel Tanks, Increases Lubricity, Dual Phase Chemistry​

 

[Portage_Bay]

JF Diesel Fuel Additive: Highly Effective Fuel Biocide Supplement, Prevents Corrosion of Fuel Tanks, Increases Lubricity, Dual Phase Chemistry​

I've used that JF for more years than I can remember. If you have bio contaminated fuel be prepared to change fuel filters often and many times.

 

[Lepke]

You can make a fuel polishing system using your primary filter. Put in a tee in the fuel supply after the primary filter and another in the return line. Add a pump that does at least 10 gph. You don't need valves at the tees. Diaphragm pumps have the equivalent of 1 way valves that only allow the fuel to flow 1 way. You can run the pump with the engine running or not.
Buy a quality fuel conditioner. I use one every fueling and never have problems even after long sitting.
Guess the amount of fuel in the tank and add a 3x dose. Run the pump, engine, or both.
You could add a vacuum gauge after the primary filter to show filter becoming filled.
This would be a good pump on ebay:

Pardon Our Interruption...

 

[fgarriso]

The only way to do it and know that it done is put an access port in the tanks. You can buy them on the internet from several different places. I would get at least a 12" port. Then you can get a flashlight in there and see all of the tank from the inside. Be prepared to do lot of wiping down with several absorbent pads. After you have cleaned the tank(s) from the inside install a polishing pump like Lepke said.

 

[Lepke]

A good fuel conditioner/cleaner will clean the tank w/o cutting holes. Baffles will block some of the tank unless several access ports are cut. Add the fuel cleaner at a high dose and run the pump.
My current boat sat 6 years, added conditioner/conditioner and ran the engines. Twin Detroits pump 70 GPH so the tanks were clean enough to go to a 2 micron filter. 3 years later during a remodel I got to the tank tops and cut ports. Tanks were big enough to walk around, and they were clean, no sludge or buildup.
And I've done it several times with client tanks.

 

[SIBERNUT]

Detroits bypass a lot of fuel. Other engines do not, so separate pump/filter works.

 

[WillieC2]

Lepke, do you recommend a specific fuel cleaner? I've got one access port in a 3 baffle tank that is practically worthless, except for telling me that there is a slight buildup of asphaltene in the vee bottom of the tank, where the fuel pickup is located. I have dual Seaboard Marine filtration with gauges that show virtually no clogging. Certainly nothing that warrants whacking 2 more holes in the tank. I did remove the hose when I had the tank empty and was able to rod the fitting at the bottom of the tank. Very little gunk but worth doing.

(Tank is 80 gallons on a 26' Nordic Tug. Yanmar 4LHTE engine with decent fuel return flow rate.)

I appreciate your wisdom. Thanks.

 

[psneeld]

I totally disagree that additives or any fuel cleaning system will clean every tank without necessary access, depending on tank design and polishing system access to every nook and cranny.

In a lifetime of cleaning all types of objects, as I assume many here have also, how many times have you had to get some type of tool or weird manual technique to get into every corner needing cleaning?

Why think some fuel tanks don't need the same?

I tried a lot of tricks with my fuel tanks and I still dind't know I had 4" of sludge in the bottoms till I cut them out of the boat. Glad I did before I every got caught in bad weather.

 

[SteveK]

I totally disagree that additives or any fuel cleaning system will clean every tank without necessary access, depending on tank design and polishing system access to every nook and cranny.

you are entitled to your opinion. The experts can't always be right. Products like Biobor JF would soon be off the shelf if they did not work as advertised.
Biobor JF has been available since 1965, so maybe next year.

 

[psneeld]

Biobor JF may prevent, but it doesn't clean up a mess that has already taken root as far as I know. Even if it did, depending on the situation, just breaking up the sludge, then getting enough agitation to get to the filters, then the dozens of filter changes to me might be less work than properly installed inspection ports.

Biobor JF is sold as a biocide, not a tank cleaner. Though as usual, there is some overlap to a degree. It is a good product, but in my experience not a miracle cure, nor any other additive I have experience with.

As a salvage guy, bet I have cleaned a few more tanks than many here including my own with professional level polishing systems.

A lot of tanks that have never had a sludge issue or ones with great fuels systems that agitate and filter well may stay clean, but I can assure anyone else here that to thoroughly clean a tank takes more access and effort than some boat tanks can get from additives and running ones engines.

There's a huge difference between diesels that circulate 50+ gallons an hour and ones like a single Lehman hard pressed to circulate more than 2gph.

So yep, entitled to an opinion. Anyone wise will defer to double checking their setup before thinking snake oil is a "clean up" answer over a preventative one.

 

[KnotYet]

Lepke, do you recommend a specific fuel cleaner? I've got one access port in a 3 baffle tank that is practically worthless, except for telling me that there is a slight buildup of asphaltene in the vee bottom of the tank, where the fuel pickup is located. I have dual Seaboard Marine filtration with gauges that show virtually no clogging. Certainly nothing that warrants whacking 2 more holes in the tank. I did remove the hose when I had the tank empty and was able to rod the fitting at the bottom of the tank. Very little gunk but worth doing.

(Tank is 80 gallons on a 26' Nordic Tug. Yanmar 4LHTE engine with decent fuel return flow rate.)

I appreciate your wisdom. Thanks.

I had an old boat with 180 gallon tanks. When I bought it, one tank was not in use due to it
having some bio contamination in it. I added Soltron fuel treatment and a DIY polishing filter.
I used an electric diesel fuel pump and would run it on that tank whenever I was on board
(including while underway which would help to agitate the fuel during the process).

I checked and changed the filter numerous times and finally was able to use that fuel tank.
No more problems and no need to open up the tank's hard-to-reach access port.
I have been told and read that it is best to avoid mixing a biocide and Soltron in the same tank.

YMMV.

 

[Davil1]

I have a 34CHB and have a persistent problem since water got into fuel 2 years ago. I used an oil pump and tried to get right to the bottom of the angled tank. I thought I got it all and it ran good at the end of the season last year. This year when I put the boat in the water the sight glass got a really dark hue. And the fuel filter plugged up again.

Does anyone have an idea of how to resolve this issue once and for all. The access to these fuel tanks is horrible!

There’s a company in town that cleans fuel tanks but it’s a major and costs thousands. Looking for a layman’s fix.

Thanks!

how big is your tank,in volume?

 

[fgarriso]

How large is your fuel tank? Where is it located? How many gallons of fuel do you normally carry? Do have single or twin engines? Do you have remote fuel filters? How much do the filter cartridges cost?

 

[Max1]

This year I recommissioned a fuel tank on this boat that was out of service for 20+ years due to neglect.
When we bought the boat, it had a rust hole in the top by the filler neck.
Over the winter I fabricated a patch for the tank and this spring, the marina welder welded up the patch.
In order to make sure the tank was bone dry, I found that if I removed the fuel level gage, the opening was exactly the size of my shop-vac hose. The shop vac hose being flexible, was able to be inserted from the top, in through this hole even though there was verry little clearance between the top of the tank and the cabin floor joists above it. There was some water in there too!. I flushed the tank a few more times for good measure before we welded it up.

Now that this (Starboard) tank is operational, I will finally be able to service the other (port) tank that has been in use exclusively for the last 20+ years. I am sure it has its fair share of silt and scum and maybe even some water at the bottom.
My mission this summer is to burn off as much fuel from the port tank as possible, then transfer what is left into the newly comissioned starboard tank. FYI, on my tank(s), I found that once the fuel pickup sucks air, there is still between 1 to 1.5 gallons of fuel (and/or water) still in the tank. Once I can no longer suck fuel through the fuel pickup line, the shop vac hose trick through the fuel sensor hole will be my go-to method for removing what is left.

also, as others mentioned here, I found I could use a prybar and several 2x4 blocks under the tank to lift a corner on the long end to tilt the tank slightly.

 

[C lectric]

I'll just add that water can be prevented from entry. Usually comes in at the filler cap due to damaged/worn O rings The fill fitting needs to be sealed also and well. I grease my fill caps every year along with the threads. I also replace the O rings every couple of years or so OR if they show ANY damage.

Water can also enter if the vent hose is attached to low on the hull side or oriented incorrectly,

Now that you have water in the fuel of course that changes things but attend to those filling fitting.

 

[Comodave]

I had an interesting call the other day from the guy we sold our diesel pusher with a Cummins 5.9 turbo to. Seems his brother in law was in a hurry at the gas station and filled the tank with gas instead of diesel. Unfortunately then he ran it until it stopped. He asks what to do? Me not really being a diesel mechanic said first thing is to drain the tank and get rid of the fuel. Then drop the tank and clean, clean and clean it out. Then remove the fuel lines and blow them out and then flush with clean diesel. He is capable of doing this work since it is basically grunt work. Then I said tp pull the injectors and have them rebuild. Maybe rebuild the injector pump. What did I miss?

 

[SteveK]

Dave, you have covered fixing the source of the problem.

Unfortunately then he ran it until it stopped.

Rebuilding the injectors suggests gas got into the cylinders before engine stopped. Perhaps no detonation, maybe gas in oil, maybe cylinder scored.
Not a diesel mechanic either, it is the sudden stop that leaves possibilities.

 

[Comodave]

Yes, I also told him to change the oil.

 

[Iggy]

I have been told, that this is the best stuff to use. Not sure, but a NL and other boaters way smarter than I suggest it.

 

[‘75 Tolly]

I had an interesting call the other day from the guy we sold our diesel pusher with a Cummins 5.9 turbo to. Seems his brother in law was in a hurry at the gas station and filled the tank with gas instead of diesel. Unfortunately then he ran it until it stopped. He asks what to do? Me not really being a diesel mechanic said first thing is to drain the tank and get rid of the fuel. Then drop the tank and clean, clean and clean it out. Then remove the fuel lines and blow them out and then flush with clean diesel. He is capable of doing this work since it is basically grunt work. Then I said tp pull the injectors and have them rebuild. Maybe rebuild the injector pump. What did I miss?

Years ago I arrived in a mining camp with my 1998 Dodge pickup (5.9 Cummins). I was unfamiliar with the enviro-tank setup and accidentally filled up with gasoline (approximately 90% gasoline/10% diesel ratio).

I then drove 15km to the drill site…ran horribly rough, low power etc. I realized what had happened, however it was critical to get up to drill site (for a drill move). Just limped it there and then back to camp.

Drained the tank the next day, filled with diesel, added an entire bottle of Howes conditioner (for lubricity).

Drove the truck for the rest of the job (snow, mud, steep mountainous terrain). No issues or symptoms….drove that truck for another 7 years before selling (720,000km on the odometer).

An anecdotal story but point is that the engine may be fine…I would refill with diesel/conditioner and just try it.

 

[PierreR]

I topped up my diesel one time with gas at night in sub zero weather. It started to run very poorly but it was the middle of the night. I remembered as a youth putting diesel fuel in gasoline to increase octane rating instead of buying expensive high test. I reasoned the opposite might work and added a gallon of 40 wt oil to the tank. I worked good enough to burn off some fuel in keep topping of with diesel and a bit more oil. Drove the truck another 400k miles.
I currently have one tank out of three that is just nasty. I used half of the tank and two filters. I have enough room in the other three tanks to pump that one dry through filters this winter.

 

[C lectric]

I'll just add that water can be prevented from entry. Usually comes in at the filler cap due to damaged/worn O rings The fill fitting needs to be sealed also and well. I grease my fill caps every year along with the threads. I also replace the O rings every couple of years or so OR if they show ANY damage.

Water can also enter if the vent hose is attached to low on the hull side or oriented incorrectly,

Now that you have water in the fuel of course that changes things but attend to those filling fitting.

I should have added the following. Check the vent hose on the hull side. THey should be high enough that water splashing cannot gain entry. They also should be aimed backwards with a downward slant.

 

[Comodave]

Finish of the story about my old motorhome. Cummins drained tank and fuel lines and it started and ran without any problems. Pretty easy fix and his insurance covered the costs.

 

[C lectric]

Another addition ss I do not see the EDIT notice so I can't change the previous additions.

THe vent hose between the tank and the hull side fitting should also be installed so the hose goes above the fitting and THEN DOWN to the tank fitting. That way if ANY small water quantity enters it will go OUT and not into the tank.

Also the deck mounted fill fitting should be SEALED and WELL. No mickey mouse installation or you may find water can still enter.

An example was a neighbour who was having fits with water entry. Time and time again he would go out one day and the next , NOT. He figured out water entry to the tank was stopping the engine. Pulled all the hoses, drained the tank and hoses, changed filters and then gave the fouled fuel away to the helper buddy. By the time I was made aware of the problem I was literally just in the way so I woild yap a bit and then leave them to their efforts.

After all the effort they finally figured the problem out. THe hose between the tank and deck fitting was LOOSE and the DECK FITTING was also loose and improperly sealed. Rain water, and we often get lots rain so the rain could get under the fitting on the deck , between the hose and the deck fitting tail and into the hose contaminating the tank again and again untill the last day. Once they took care of ALL of it no more trouble.

But unfortunately Several trips were fouled due to the water entry.

So be very aware that all of the tank filler equipment must be attended to and fittings must be installed correctly and clamps TIGHT or at least firmly clamped.

 

[Comodave]

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