Fuel Tank Sludge Hunter 356

[peterwynndavies]

On my 2002 Hunter 356 by removing the sender there is about a 2 inch hole through which I can just see a disc of sediment floating threateningly beneath the fuel pickup. The boat is running fine and the filter not bad.
How can I remove the sludge without removing the tank? I have a small pump and ideally would remove the fuel pickup and drop my pump tube straight down but it looks like the pickup has fittings on the inside of the tank which must have been installed during manufacture. I'm loathed to put an inspection hatch in because of the inevitable debris and sealing.
Any advice appreciated.
Peter

 

[Sailgunner]

Install an inspection plate. Clean the tank every year.

 

[Tally Ho]

Maybe you could use a liquid transfer pump (even a cheap manual one) and try to “skim the top” of the fuel where you are seeing the crud. Only works if it is floating on the top surface though.

Greg

 

[Tom J]

If there is a mobile fuel polish service available, they could put a couple of hoses down the hole and do a good job of flushing out the tank, and restoring the fuel. This might not get all the sludge, though, and creating an inspection hatch as others have mentioned might be necessary.

 

[shemandr]

Why not use one of those fuel extractors? They have a tube you run to the bottom of the tank thru the gauge hole. Buy a new gasket for the sender. I think mine had five holes and it mattered which way the gasket was oriented.

 

[Ralph Johnstone]

Fuel inspection port, guaranteed not to leak. Even if the tank is overfilled.

I remove the 3/8" plug every other year and send down a 1/4" tube from the Pela vacuum oil extractor looking for water and crud. The tanks sits on a very slight angle towards the centre so most of the crap is along that edge. If I'm really inspired, I'll send down the borescope to see what's going on in there.

To me, the risk of suffering fuel leakage from a large inspection plate is not worth it.

 

[chp]

I thought I would jump in on this thread instead of starting a new one. On my new to me 1996 280 I had a fuel starvation problem at the end of the season. Only had the boat for a month. Previous owner told me of this problem he had had a few times. He had new fuel lines and filter installed and also drained the tank and replaced with new fuel. He didn't have any issues all last year. When the engine quit on me I removed the fuel line from the tank to the Racor filter and could not draw any fuel out of the tank. I blew hard into the fuel line and could hear the bubbles in the tank. As soon as I did that fuel came flowing out the line on its own. Re-attached the hose and all was fine. Figured the pesky screen at the bottom of the tube might be the problem. Today I removed the pickup and no screen at the bottom.
My question is, is it possible I blew the screen off. I don't know how well that screen was held onto the bottom of the tube.

 

[jssailem]

Is it possible I blew the screen off.

While anything is possible, if you find the screen in the tank you would have your answer.

The PO told you he refilled the tank. Did he clean the tank first? It is possible contaminates (sludge) were on the tank bottom. It was stirred up and blocked either the screen or the pickup tube. You blew it out of the tube like a straw with a chunk of strawberry in a strawberry milk shake.

Check out the additive ideas for diesel fuel discussed her on SBO and in sailing magazines. I dissolved the sludge that had built up in my tanks and flushed the debris into my Racor 500M filter.


It takes time but saves tossing $5.00/ gal plus fuel.

 

[DArcy]

It sounds like the sludge is in the bottom of the tank. I had this problem on my previous boat and was able to suck the gunk from the bottom of the tank using a PELA 6000 fuel extractor. They come with a long semi-rigid suction tube great for waving around the bottom of a fuel tank sucking up sludge. It worked WAY better than I thought it would at first. It was very satisfying to watch the sludge get sucked up.
I took the contaminated fuel to a garage that dealt with it appropriately but you could filter it and put it back if you were set up for this.

 

[fox9988]

I blew hard into the fuel line and could hear the bubbles in the tank. As soon as I did that fuel came flowing out the line on its own.

Sounds like the tank vent is plugged creating a vacuum and starving the engine of fuel. Take the vent hose off and try blowing through it.

 

[chp]

Sounds like the tank vent is stopped up creating a vacuum and starving the engine of fuel. Take the vent hose off and try blowing through it.

Thought of that as well. removed the vent line and it is clear

 

[chp]

It sounds like the sludge is in the bottom of the tank. I had this problem on my previous boat and was able to suck the gunk from the bottom of the tank using a PELA 6000 fuel extractor. They come with a long semi-rigid suction tube great for waving around the bottom of a fuel tank sucking up sludge. It worked WAY better than I thought it would at first. It was very satisfying to watch the sludge get sucked up.
I took the contaminated fuel to a garage that dealt with it appropriately but you could filter it and put it back if you were set up for this.

I actually have an oil extractor which I was thinking of using. It hold 8 litres at a time. I was thinking about using it to suck out any crap. Might try it.

 

[chp]

While anything is possible, if you find the screen in the tank you would have your answer.

The PO told you he refilled the tank. Did he clean the tank first? It is possible contaminates (sludge) were on the tank bottom. It was stirred up and blocked either the screen or the pickup tube. You blew it out of the tube like a straw with a chunk of strawberry in a strawberry milk shake.

Check out the additive ideas for diesel fuel discussed her on SBO and in sailing magazines. I dissolved the sludge that had built up in my tanks and flushed the debris into my Racor 500M filter.
View attachment 203791

It takes time but saves tossing $5.00/ gal plus fuel.

I think he just sucked out the fuel through the filler neck. What biocide did you use to dissolve the sludge. The discussion on fuel additives could take months to read through them all.

 

[ice breaker]

I had a similar problem when I first purchased the boat. Aggressive sailing in rough water, stirred every thing up. The filter was fine, but the 90 degree elbow coming of the tank was plugged up with all of the paper like sludge. I needed to use a coat hanger to poke it out. Just as mentioned above the oil extractor works great to get the tank trash out. I now biocide after every fueling and have never had any issues after that.

 

[kappykaplan]

I now biocide after every fueling and have never had any issues after that.

 

[jssailem]

What biocide did you use to dissolve the sludge

In context, when I bought the boat (2015), the 2 tanks in my bilge had about 150 gallons of unknown aged diesel fuel. Fuel at the time was running in the mid $3.20-$3.50 range. I figured I had about $500 of fuel in the tanks.

I read in Practical Sailor at this link Diesel Additives - Practical Sailor about the affect additives have on the stuff growing in the absorbed water found in our diesel fuel. P S now has an E-book on the subject from their experiments.

I use a combo mix of Biobor JF and Star Tron added to the tank at each fueling. I am sure it was not simply one thing but a combination of effort combined with the filtering of the fuel. I ran through a number of filters while at the same time adding fresh fuel to the mix. Now 7 years later I have clean tanks based on looking into the tank with a flashlight. I change my filters once a year. No more do I have an engine that coughs sputters and dies because the fuel line or filter is clogged.

 

[chp]

In context, when I bought the boat (2015), the 2 tanks in my bilge had about 150 gallons of unknown aged diesel fuel. Fuel at the time was running in the mid $3.20-$3.50 range. I figured I had about $500 of fuel in the tanks.

I read in Practical Sailor at this link Diesel Additives - Practical Sailor about the affect additives have on the stuff growing in the absorbed water found in our diesel fuel. P S now has an E-book on the subject from their experiments.

I use a combo mix of Biobor JF and Star Tron added to the tank at each fueling. I am sure it was not simply one thing but a combination of effort combined with the filtering of the fuel. I ran through a number of filters while at the same time adding fresh fuel to the mix. Now 7 years later I have clean tanks based on looking into the tank with a flashlight. I change my filters once a year. No more do I have an engine that coughs sputters and dies because the fuel line or filter is clogged.

Thanks for the link. Very interesting and I will be definitely following that combination. I used a similar combination in my old boat with a 2 stroke outboard. Star Tron for ethanol and StaBil. Always started with one pull.

 

[fox9988]

@chp whats the verdict?

 

[chp]

So. I made a fuel polisher and sucked out a lot of crud. In fact the sludge plugged up my 3/8 pickup line. I got a lot out but now where near all as I could only access through the level indicator hole. I had the engine die on me about a month into the season again. Easy to get it going , but messy and annoying. I once again ran the polisher as the crud had moved again to the pickup tube. I finally got some Biobor and adding a shock treatment. I also use Diesel clean as an additive. I think that killed off the bug from growing, however you're still stuck with the crud. It doesn't break down and while my engine never quit it did once in a while start to loose power. Next additive was Diesel clean tank and fuel system cleaner. This is specifically made to break down the crap into microscopic particles. I 've never had anything in the Racor filter until I added this stuff. I had to clean out the seperator twice and about to change the filter as well. So far after 50 hrs not even a hickup or burp from the engine. Pics attatched show the back crap on the bottom of the tank and the other was within 5 minutes of the fuel polisher running.