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Tips or tricks to getting sediment out of the gas tank...

GAS engine, transmission and generator repair and maintenance discussion forum.
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Tips or tricks to getting sediment out of the gas tank...

Postby 390Express » July 30th, 2018, 1:07 pm

I've drained my starboard tank twice now, gas looks good when I drain it. I've been draining it right from the rubber line that attaches to my Oberg fuel filter, so it should be the same gas that the fuel filter is getting, but when I clean the filter and run it, I only get about 2-3 minutes of run time out of it before the filter is clogged again.

The supply line failed, and gelled shut. The return line was always open and looked good, but it had a small amount of the gel like substance (the substance you get when separated ethanol reacts with rubber fuel line) in the hose. I'm wondering if my return line failed and is deteriorating, thereby introducing sediment back into the tank, and causing my issue. I'm going to replace both return lines this week. They're about $40 each, it's a fairly cheap investment.

This is maddening. I've drained my starboard tank twice, and my port tank once. Still bad gas. The gas is now clean, smells right, and its useable when I drain it, but has a lot of sediment clogging material, only when its ran through the boat. Ran out of the boat it looks great and I dump it right into my truck.

I've also considered hooking a pump up to the motor, and running a continuous loop from the supply line, to the pump, to a filter, to the return line, and letting the gas cycle through a filter for 20-30 min. intervals.

The other option is to nix the Oberg fuel filter, and replace it with a can style filter that can hold more sediment.

I never thought that getting bad gas out of the tanks would be the single hardest part about getting this boat right. Everything else runs well. (Aside from erratic idle on the port motor, but I can't diagnose that, until I'm sure that the gas is right.)

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Re: Tips or tricks to getting sediment out of the gas tank...

Postby bud37 » July 30th, 2018, 1:29 pm

One of the interesting properties of ethanol gas as I understand it, is its ability to clean things.....so if you have a system that has never had ethanol ,then does, it will now clean the residues from all it touches, but as it does this it keeps it in suspension that passes thru filters , so while running all is well, upon shutdown it drops back out and clogs stuff.
Just something I came across while reading about fuels, sounds like it might be reasonable given the problems boaters are having after switching.

I think if one really wanted to clean a tank and be done with it, you would have to hire a service that can vac it out and wash the tank etc...good luck man.
The above is strictly my opinion.
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Re: Tips or tricks to getting sediment out of the gas tank...

Postby 390Express » August 2nd, 2018, 12:55 pm

I'm pretty confident that I was right that the return fuel line had in fact failed and was introducing new sediment back into the tank. There is a fuel filter before the pump, so there should be no sediment in the "system." The TBI injectors are not clogged, so no sediment should be getting to the injectors themselves. (they have little screen filters on them, and those filters are not clogged) However, when I disconnected the fuel return line, and emptied the small amount of gas that was in the fuel return lines, there was all sorts of sediment in them. There really isn't any other place, other than the lines themselves, for the sediment to come from - ergo, it's likely or proven that the fuel return lines were bad.

I replaced the fuel return line on the starboard motor, hooked up a pretty large 12v, 10gph pump, hooked a can style fuel filter/ water separator to the pump, and connected the pump and filter to the system in the same manner as the factory pump and filter. I ran the system for 30 min like that, just cycling the gas that was in the tank. I went to the gas station, picked up another 10 gals of fuel, and ran the pump again for 30 min, while I was adding the new 10 gals to further agitate and stir up the gas in the tank... knock on wood, seems like I'm good to go.

Boat ran for an hour on the main tank. It's the longest its ever ran on the main tank, and has restarted twice since running for an hour, with no issues. I plan on taking it out this weekend. We'll see... I'll keep you updated.
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Re: Tips or tricks to getting sediment out of the gas tank...

Postby 390Express » August 16th, 2018, 6:08 pm

I was still having sediment issues, and I was sick of having to constantly pull the Oberg filter and clean it out, so I went ahead and added a 2nd can style filter, in addition to the Oberg fuel filter. After adding the can style, I can that emphatically that I believe the can to be superior in virtually every way to the Oberg filter. In a perfect world, the Oberg works, and it has bonuses (easy to take the screen out and have a look at what's going on), but the can style filter is much, much more effective, and acts as a water separator, whether it's branded that way on the filter or not. I'm currently using FRAM EXTRA GUARD PH8A oil filters for $3.99, and they're working wonderfully. I'll edit my post to add pics of my setup, but it's worked great. In addition to sediment, I have found that I still have small amounts of water in my system, even after draining the tank twice and refilling with stabilize, enzyme treatment, and 30-40 gallons of good gas.

I've been cautioned on here about running two filters, and did not want to do it for a number of reasons, but read that it is perhaps necessary on the WIX page, whom seemed to provide an endorsement of the same. I know - Wix sells filters, they'll tell you anything, right? Well, they could say to eliminate your old system and install theirs, but the actually recommend adding a 2nd filter. After adding the 2nd filter I can now run my boat for about an hour and half. It's the size of the filter vs the Oberg that makes the biggest difference, and I love that the can style is trapping more water than my prior filter. (water was getting past my prior Oberg filter, and causing me RPM issues) Motor used to hesitate and sputter around 3000 RPM. I believe that was caused by the small amount of water in the gas. Now it rpms to 4000k no problem, and I'm confident that it will hit 4,500 if I ask it to. Ran the motor for about 5 hours last night. I had to drain the fuel filters of water twice, but was able to recycle them more or less (turn them upside down, and drain out the water and gas, and use them again). I plan on keeping 4 of them on the boat for when I'm out on the lake, but it's running for over an hour with its current setup. The extra filters are more precaution than anything.

If you don't have a can style, I would recommend adding one asap. Pics to follow. The system that I installed required no bolts, no modification, and can easily be switched back to the factory configuration in 10-15 miuntes. After running 40-50 gallons through it, I think I'll try going back to the Oberg alone. We'll see.
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Re: Tips or tricks to getting sediment out of the gas tank...

Postby mjk1040 » August 19th, 2018, 8:02 am

My Friend 2 items I would like to make you aware of! The Fram Filter using is an oil filter, not a fuel filter I do believe and I would suggest not using Fram Oil filters on your engines if you have seen any of the oil filter comparisons on You Tube, etc.
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Re: Tips or tricks to getting sediment out of the gas tank...

Postby Viper » August 19th, 2018, 7:04 pm

mjk1040 wrote:Source of the post My Friend 2 items I would like to make you aware of! The Fram Filter using is an oil filter, not a fuel filter I do believe and I would suggest not using Fram Oil filters on your engines if you have seen any of the oil filter comparisons on You Tube, etc.

++
PH8A is for oil! Ditto on the Frams.
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Re: Tips or tricks to getting sediment out of the gas tank...

Postby 390Express » August 22nd, 2018, 1:39 pm

mjk1040 wrote:Source of the post My Friend 2 items I would like to make you aware of! The Fram Filter using is an oil filter, not a fuel filter I do believe and I would suggest not using Fram Oil filters on your engines if you have seen any of the oil filter comparisons on You Tube, etc.


The Fram extra guard can be used for fuel or oil, and is marketed as such. I'm using it more as a large sediment filter, with another filter behind it. There's no way for the quality of filter to hurt my motor(s). They're working great and doing exactly what I want them to do. The only thing I'm considering is buying a sierra fuel filter/water separator with a drain on the bottom, but I'm having trouble finding said filter with a 3/4 thread.
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Re: Tips or tricks to getting sediment out of the gas tank...

Postby 390Express » August 26th, 2018, 2:09 pm

Gah, at a crossroads (again)...

I talked to the mechanic at my marina, and he said that they would have pulled the fuel sender, and drained the tank(s) completely. I wish I would have done that from the beginning, but at at this point I'm pretty close to being good. It's fairly simple to get to the starboard fuel tank sending unit (I can access it from the aft cabin, I wanted to avoid running a hose through the aft cabin to get the fuel out), but I think the port sending unit is beneath the fridge in the cockpit area. That fridge has been acting up (cabin fridge is fine), so it may be a good idea to pull it anyhow, but it seems like a huge headache.

Both motors start and run for hours at this point, even with a small amount of water in the tank(s). The starboard motor will operate under a load, and drives fine, the port motor will not currently maintain a steady RPM or operate under a load, but it's getting close. Both motors will run for over an hour with a BS Fram PH8A filter. I can drain the PH8A and re-use them, it's water that is giving me the brunt of my problems.

Should I

1) start over (again) and drain the tanks (again)?
2) Run the boat for 10-12 hours until the tanks are near empty (as empty as they can be with the pickup tubes); or
3) Add a ton of good gas (approximately 100 gallons per side), to further disburse the small amount of water in the tanks.

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Re: Tips or tricks to getting sediment out of the gas tank...

Postby Viper » August 26th, 2018, 2:32 pm

390Express wrote:....The Fram extra guard can be used for fuel or oil, and is marketed as such.......

Yes but is it specifically designed to separate water? That is a must in a marine application.

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Re: Tips or tricks to getting sediment out of the gas tank...

Postby Viper » August 26th, 2018, 2:56 pm

390Express wrote:Source of the post......There's no way for the quality of filter to hurt my motor(s)......

You may want to re-evaluate that statement. I'd say a sudden loss of oil pressure at high rpm due to a failed oil filter would be enough to harm your engine if not caught in time. Had it happen three times. In each case, the fault was the filter. Of every brand I've used, the only oil filters I've had fail were Frams. Giving them 3 chances over a two year period was enough for me to not recommend them anymore. That's a pretty high failure rate considering they weren't the main brand I was using at the time. Maybe they've changed but there's no way I want to risk anything I work on or own until the general concensus convinces me otherwise. For now, that's not the case, but don't take our word for it, there are many wright-ups on the internet of similar experiences.

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