20 year old varnish in tank 208

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rmf4grady

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I have posted here before related to my ongoing work on my 2000 208. Replaced the transom, all electrical wiring and found a nice
2020 DF 175a zuk with 200 hours for 7K to replace the yamy 2 stroke. Everything was going great until I took it on a shakedown cruise.
When I started working on the boat the tank was emptied, and I ran the motor on an external tank. I started putting gas in the below deck tank and it
was going great so I figured not much varnish. I put 40 gal in and it ran great, but I still hadn't put the boat in the water. Well first trip out
and put it up on plane, it sputtered to a stop and was towed home. After some troubleshooting, I found the gas was crap, filled with varnish.
Is there any way I can clean this shit out or am I just screwed? I'm going to put a small external tank on it tomorrow and hopefully it will run smooth.

Any ideas?

Rich
 
Do you have an inline filter before the engine? What has it collected? Are you sure it’s not water?

Ethanol is a great solvent. It will free up varnish and dissolve fiberglass tanks. The sludge can destroy your new engine too.

Pump some fuel into clear container and let it settle. Put a photo up.
 
Was the gas you out in ethanol?
I think there may be water in the tank since your motor died when getting on plane. In that case the bow is angled up and the gas and water move aft in the tank in effect making the water level deeper. Now the motor may be sucking mostly water.

To check, dump the contents of the water separator/main filter into a glass jar and let it sit for 10 or 15 minutes. See if you have water on the bottom of the jar.
You didn't say if there was old gas in the tank already. It is possible that you had bad/stale gas.
When you added 40 gal of gas, what did the fuel gauge say. Ft that hull, 40 gallons is half a tank.
 
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seasick said:
Was the gas you out in ethanol?
I think there may be water in the tank since your motor died when getting on plane. In that case the bow is angled up and the gas and water move aft in the tank in effect making the water level deeper. Now the motor may be sucking mostly water.

To check, dump the contents of the water separator/main filter into a glass jar and let it sit for 10 or 15 minutes. See if you have water on the bottom of the jar.
You didn't say if there was old gas in the tank already. It is possible that you had bad/stale gas.
When you added 40 gal of gas, what did the fuel gauge say. Ft that hull, 40 gallons is half a tank.
Click to expand...
OK I will post a picture of the stuff today. What I recall is mostly slimy brownish liquid on the bottom and a layer (maybe about 15% of total ) of what looks like pristine gas on top.
 
rmf4grady said:
OK I will post a picture of the stuff today. What I recall is mostly slimy brownish liquid on the bottom and a layer (maybe about 15% of total ) of what looks like pristine gas on top.
Click to expand...
I had removed the old gas from the tank about a year ago. I did leave the fuel pickup tube assembly loose so any water/gas vapors could escape. Its not impossible that some water may have gotten in the tank, but when I put 40 gallons in it read about half full.
 
Hookup1 said:
Do you have an inline filter before the engine? What has it collected? Are you sure it’s not water?

Ethanol is a great solvent. It will free up varnish and dissolve fiberglass tanks. The sludge can destroy your new engine too.

Pump some fuel into clear container and let it settle. Put a photo up.
Click to expand...
About 15% layer on top of good gas with the rest brownish oily muck..
 
rmf4grady said:
About 15% layer on top of good gas with the rest brownish oily muck..
Click to expand...
yes i have 3 filters 1 raycon-type water/fuel one car type fuel only and one water/fuel that's part of the engine.
 
rmf4grady said:
About 15% layer on top of good gas with the rest brownish oily muck..
Click to expand...
Probably water. I dealt with water in fuel problems for a few seasons. If there is ethanol in your new fuel it will separate out if too much water in the tank. Could also be condensation or missing o-rings on Perko fuel fills.

"A blend of 85% gasoline and 15% MTBE can hold only 0.5 teaspoons at 60 degrees F per gallon before the water will phase separate."


Water fuel 2.jpg Water fuel.jpeg

I have found it very difficult to clean up the tank. Ethanol and water will go to the bottom of the tank. Gasoline will float. Even if you pump out the water smuts out thru the sending unit you will still have water in the fuel to deal with.

Hookup1

Post in thread 'Getting gas from boat gas tank'

I built a transfer hose using an automotive fuel pump. I disconnect fuel line to engine after the primer bulb and connect pump setup. I use it to get ethanol free fuel out of my boat for my lawn equipment.

1729616976611.png
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rmf4grady said:
I had removed the old gas from the tank about a year ago. I did leave the fuel pickup tube assembly loose so any water/gas vapors could escape. Its not impossible that some water may have gotten in the tank, but when I put 40 gallons in it read about half full.
Click to expand...
Then you have to do it again and this time better.

Find a company who can remove the old fuel, fuel polishing companies for example or do it again by your self.
Have boat sit stern low, as lowest as possible and use a stiff hose you can move around to suck out the bottom near rear wall as stuff usually accumulates there.
Use water separating fuel filter with clear bowl below to see dirt and water before it reaches the engine, get enough filters to replace as soon bowl get dirty or traces of water show up. Do not use any filter where you can't see what contamination is inside and you should not use 3, one good and big with transparent bowl and the engine mounted one, check frequently for contamination to catch it befor it gets inside VST and the injectors.

Stuff can be also stuck on the baffles, thats maybe the reason why after cleaning first time sludge returned as it got washed away by boats movement and by the fresh (ethanol) fuel.

Without photos it's difficult to say what the contamination is, "brownish, oliy much" let me think that its also old 2 stroke mix.

Chris
 
Yes, we used this using a car fuel pump in the ship yard but it was slow as hell but some pumps may be faster.
My buddies shipyard has a professional system with a high speed pump and 3 racor filters in series to either pump it out in to jerry cans or barrels or recircle polished fuel introducing the exit hose to the fuel filler cap. However, in both cases it's important to check the fuel filters bowl to realize when the bowl is full of water or debris.
That is what i would build if i would have serious problems with contaminated fuel tank/s.
Chris
 
here is a sample of what i got out of the tank
 

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rmf4grady said:
This gas came from BP station. Says 10% Ethanol(BP Silver)
Click to expand...
The ethanol will strip varnish off tanks and break down old non-ethanol hoses. Color may not be related to that. Doubt it's oil - should have been oil injection before). Sometimes it's the red fuel stabilizer. 40 gallons of the fuel is 36 gallons of gasoline and 4 gallons of ethanol. All it would take is a cup of water (48 teaspoons) to saturate the ethanol in the fuel and have it drop out.

Whatever it is you have to get it out! Get the bow of the boat up high. Remove sending unit. I use my automotive pump with a non-sparking copper tubing straw to go into the sending unit hole and get the water out of the bottom of the tank. I put a little dry ice in the tank before I start to reduce explosion risk (tank 1/2 full of air and gasoline vapors). I don't take all the fuel out - just get as much water out of the bottom of the tank as you can.

There will still be water in the fuel tank and fuel. I run it out. I use Sierra clear bowl fuel/water separator/filter. Take the boat out, shake up the tank and run it. The idea is to get water into suspension and collect it in the filter. Stop and check the bowl. If it has a lot of water stop and drain it. You have to repeat this over a couple of hours of running.

The fuel that you are burning will have lower octane without the ethanol. Don't run it too hard. Once cleaned up give it a treat of premium fuel. Keep an eye on that clear bowl.

I have tried to dispose of bad fuel but have never found a way to do it. Someone told that Northstar Salvage will at about he same price per gallon as you put in. Best answer I found was burn it!
 
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