Seeing Red

[daniel123]

I upgraded the standard Sierra fuel filter my local marine mechanic installed on my 1999 200 Osprey last January and over the weekend installed a Moeller filter/separator with the clear reservoir on the bottom with the valve to drain water. That Sierra filter I replaced had no more than 20 gallons of fuel run through it since this past spring, and probably much less. The fuel was a combination of non-ethanol purchased from a gas station in Florida in December topped off with 10% ethanol fuel purchased in June at a BP station. The fuel was double-dosed with fuel treatment, primarily (light blue-colored) StarTron but perhaps with a double dose of (red) Stabil as well, since I knew it would/had been sitting for a few months.

The Osprey manual says the tank has a capacity of 45 gallons. The past two times I have filled it after the fuel had been drained by the local marina for winter storage, it accepted only 25 gallons, so I am still not sure if I have a 45 gallon or a 25 gallon tank, or if it was not actually completely drained each time, but that's not the concern at the moment (!)

Also, the outboards ran well with the fuel this spring/summer, both the old 115 two-stroke and the new-to-me 2013 ETEC 130 I just had installed.

The problem is, when I poured the fuel that was in the Sierra filter canister into a clear container, it came out red and quickly separated (see photo) into about 50% red at the bottom and 50% clear at the top, with a few small flecks of yellow goo suspended in the 'layer' that separates the two.

The filter apparently performed as intended: filtered the fuel and separated the water that was obviously in the fuel, from the gas it allowed to continue on to the outboards, which as I said, ran fine.

But what would cause that color? The red Stabil? If so, why would it color the water and not the fuel? And what might the yellow stuff be?

Regardless, I assume I need to drain and discard that fuel that remains in the tank. I also was told by a local marine mechanic that those Moeller filters with drain valves are not recommended in open boats as they can fail and leak gas into the bilge/water? I welcome any and all thoughts. As well as advice on how best to drain and try to clean the tank myself. 

[wingtime]

That is some nasty fuel.  It is either phase separated or fuel and water.  I'd draw some fuel out of the tank and put in a jar and see what it does.  Personally I'd drain all the fuel out of the boat.  The Etec is very sensitive to fuel quality.  I'm not sure about the smaller Etecs but I think it has a water separating fuel filter on it as well.

In the future I would not bother with the red stabil.  Odds are thered color is just that... red dye from the stabil..  I would not store the boat with fuel in it for the off season.  your better off draining it and using it in your car.

I personally only run Non-ethanol fuel in my boats. 

It is possible someone changed out the fuel tank with a smaller tank at some point.  I [ull the inspectiuon pie plates and see if you could find a tag on the tank to confirm its size.

[daniel123]

I'll try to pump a bit of gas out of the fuel filler and give it a look. I hesitate to remove the sending unit access any more often than necessary due to issues with stripped threads/resealing it in the past.

The stamp on the poly tank there says 45 gallons. But even after it's been drained I've never been able to put more than 25 gallons in it...

[wingtime]

Ok you have a 1999 200 Osprey. By then they stopped building them with a fuel tank hatch cover. So unless your floor has been cut, you have the original poly tank. 

Your pick up tube could have a hole in it or is broken off... so your not getting all the fuel out. Also... Is your vent clear?

If your not getting all the fuel out of the tank than your just mixing good gas with bad gas... and guess what the stuff that is on the bottom is the worst.

[daniel123]

That's good info about the tank hatch/tank size and it being original.

Both times the tank has been drained it was via the sending unit port atop the tank, accessed via a deck plate in the floor just aft of the center console. I assume they use a separate hose to suck out the fuel, and not the fuel line/pick-up. And they inspected the pick-up last winter and said it was fine. So that eliminates that being the culprit. Any other thoughts?

Dan

[daniel123]

I drained the Osprey's 50 gallon fuel tank yesterday at my marina and found no hint of red in the 25 gallons we pumped out. Which is weird because there was so much red in the filter when I removed it a month or so ago (reported here). But there was some water in the fuel we drained yesterday.

The bottom red layer in the jar of that gas I saved from the fuel water separator/filter tested positive for water with Gasoil paste. I still wonder why it was red? And why just the water and not the gas? I have used (red) Stabil but also (clear) StarTron, to treat the fuel in that tank.

The marine mechanic also recommended I put an anti-siphon valve in the fuel pick-up for safety's sake, citing its ABYC recommendation. I know that's been a frequent subject on this forum, and has been pointed at as a cause of fuel flow problems. I welcome comment on that.

When the tank was empty, we noticed it shifted when we applied some torque to the the filler port hardware, which means the straps to secure the 50 gallon poly tank have come loose/broken. How big an issue is that and how can it be fixed?

We were able to refill the tank with 45 gallons, which means my previous end-of-season drain jobs, after which it only took 20 gallons to "fill" it, were not complete drainings performed by  the crew at my previous marina.

Dan