Fuel issues in the U.S. ethanol in the gas

[pathalla]

Called Yamaha here recently regarding recommendations on fuel water separator filters and was told their minimum recommendation for filters was a 10 micron filter/ 90 gph for the 250's. This was not what I had installed. We then changed them. Apparently ethanol acts as a dispersant, breaking contaminents down into smaller particles and if you do not have a adequate fuel system filter guess where it ends up? I like my motors running just as they are without fuel system problems and thought others on this forum might want to know about this so... check with your manufacturer.

[jyasaki]

FWIW, this is more of a problem with older fiberglass tanks, and in that case, a filter will not help. The ethanol apparently dissolves some of the resins that were used in older glas tanks, and this ends up separating out when the fuel is burned, coating valves and other internal parts with a thick black goo.

Also, rumors of MTBE and ethanol being imcompatible (also forming a sludge type material) are starting to surface.

Alcohol in the fuel *may* break down other deposits that are present in the fuel system, causing them to head engine-ward. This is the reason for a small particle filter. You should, ideally, watch for filter clogging for the first few months after going to an ethanol/gasoline blend.

And, as always, the infamous phase separation rumors (alcohol pulling water from the air, and then having the water settle out, rather than being distributed through the gas (this is the part of the water separator recommendation.)

As I recall (and I may very well be wrong on this one) the standard Yamaha in-line water separating cannister filters are 30 micron filters. I *think* that 10 micron Racor elements will fit on the filter mount that is supplied by Yamaha.

[Note that if you have the filters mounted in an enclosed area (or maybe it's just the engine room), the USCG requires metal bowls, not the see-through plastic ones.]

My boat, luckily, came with a 10 micron Racor on a Racor mount.

Luck;

jky

[Poly]

Originally Posted by jyasaki

And, as always, the infamous phase separation rumors (alcohol pulling water from the air, and then having the water settle out, rather than being distributed through the gas (this is the part of the water separator recommendation.)

I'm not sure the thermodynamics of that make sense to me...

[jyasaki]

Originally Posted by Polwart

I'm not sure the thermodynamics of that make sense to me...

Not sure what part of my statement raises thermodynamic questions, but to be honest, none of it makes all that much sense to me. Just reporting the rumors and concerns I've heard.

http://www.epa.gov/otaq/regs/fuels/rfg/waterphs.pdf

http://www.chevron.com/products/prod...concerns.shtml

The problem, as I understand it is that an ethanol/gas blend, when undergoing phase separation will settle the alcohol/water mix out, but it will still be combustible (to a degree.) MTBE oxygenated fuel will also separate, but the water will not combust, so the motor stops. Running on the alcohol/water mix essentially creates an extremely lean mixture, which may (probably will) cause engine damage.

Of course, that condition is exactly what the water separator is supposed to stop, so that's all theory anyway.

jky

BTW, if you specify what your question is, I might be able to give you better info, or at least point you to where you can find it.

[pathalla]

Originally Posted by jyasaki

As I recall (and I may very well be wrong on this one) the standard Yamaha in-line water separating cannister filters are 30 micron filters. I *think* that 10 micron Racor elements will fit on the filter mount that is supplied by Yamaha.

[Note that if you have the filters mounted in an enclosed area (or maybe it's just the engine room), the USCG requires metal bowls, not the see-through plastic ones.]

My boat, luckily, came with a 10 micron Racor on a Racor mount.

Luck;

jky

Yamaha makes a 10 micron filter which is what we installed. I got the impression from the folks at Yamaha that the problem was related to contaminants already in the fuel in certain areas of the country, not contaminants in your boat, so err to the side of caution, and install the better filter.

[jyasaki]

Makes sense in any case.

Fuel contaminants from bunkered fuel are, while a concern, not going to be widespread, I think. One tank, and most will be gone (hopefully clogging someone else's filters and injectors.)

I personally worry more about the rumors of MTBE and ethanol not playing nice together.

jky

[Poly]

Originally Posted by jyasaki

Not sure what part of my statement raises thermodynamic questions, but to be honest, none of it makes all that much sense to me. Just reporting the rumors and concerns I've heard.

http://www.epa.gov/otaq/regs/fuels/rfg/waterphs.pdf

http://www.chevron.com/products/prod...concerns.shtml

The problem, as I understand it is that an ethanol/gas blend, when undergoing phase separation will settle the alcohol/water mix out, but it will still be combustible (to a degree.) MTBE oxygenated fuel will also separate, but the water will not combust, so the motor stops. Running on the alcohol/water mix essentially creates an extremely lean mixture, which may (probably will) cause engine damage.

Of course, that condition is exactly what the water separator is supposed to stop, so that's all theory anyway.

jky

BTW, if you specify what your question is, I might be able to give you better info, or at least point you to where you can find it.

I think the EPA document answers my questions. And basically what is says is that ethanol based fuel will take around 2 years under normal storage conditions to soak up enough moisture to cause phase separation (and until that happens the effect of the moisture will not be noticeable). So contrary to the rumours you may have heard ethanol based fuel will not "suck the moisture out of the air and then separate it out" (it was this part I was strugling with). There is a slightly higher risk of condensation or direct water contamination causing you a problem but I doubt that a modern engine would run well enough on a water/ethanol mix that you wouldn't notice the problem, and as you say almost all boats have some sort of fuel water separator. I doubt the majority of people will ever notice the difference.

[jyasaki]

FWIW, I agree with you, Polwart.

However, like many things that happen here in the US, people start screaming and crying wolf whenever a change is mandated.

I was not voicing my fears and suppositions; simply relaying concerns and problems that have been tossed around on various forums on this side of the pond.

jky