articfriends

iTrader: (1)

When 10% Ethanol fuel replaced everything that you find at most pumps, they replaced the fuel additive (tolulene etc) that gave gas its octane WITH the ethanol. I read that the base stock of gasoline thats left once the ethanol has went thru phase seperation is in the 82-85 octane range. As far as "fancy electronics" saving anyones motor, they have a knock sensor and although it can pull timing out once it hears motor detonating, it can't fix your injectors once the water that was absorbed into the ethanol due to its high hygroscopic tendencies ruins them or your piston crowns or rings once those fouled injectors go lean start acting up. Every fall I run my boat down fairly low and then in the spring I pump the tank dry into my work beater and my sons beater, Smitty
http://www.blackjackcove.com/files/B...ransaction.pdf

But even if every drop of MTBE gas is out of your tank, ethanol’s properties as a solvent will still
loosen deposits in fuel tanks and lines leading to clogged filters, carburetor jets, or fuel injectors.
If you have an older boat, expect to change filters much more frequently this season. Keep
spares aboard so a clogged filter doesn’t leave you stranded when it starves your engine for gas.
The other concern with E10 is ethanol’s affinity for water. Ethanol absorbs water — for years
ethanol was sold as “dry gas,” an additive to remove water from gas tanks. And it works — to a
point. E10 gas will phase separate, or spontaneously divide out into its component parts in the
presence of as little as one half of one percent water. This means that if a boater with a 100-
gallon tank has as little as half a gallon of water in the bottom of the tank and adds E10 gas, the
ethanol in that gas will separate out and could render the gas unusable in many cases.
Without ethanol blended in gasoline, it reverts to low octane base stock. Typical 87 octane E10
that phase separates would become 83 or 84 octane fuel, which would cause knocking in most
engines, or not run them at all. Premium grades of E10 that were sold as 93 octane at the pump
would become 89 octane if separated, which would still run most engines, but could void the
warranties of some high performance engines.

jeffswav

I missed this one, this looks like some of the stuff I have posted lately. x2

jeffswav

You can post this 100 times and people just don't get it. It seems more and more people are trashing engines lately. The marinas are swaping out motors and collecting the cash. Most of them could have been prevented with fresh fuel.

Young Performance

Sorry John, but had i known the fuel was a year old, I would have had MAJOR concerns. I was under the impression that it was only a few months. I was also under the impression that it was 93 octane, non-ethanol fuel. There is a huge difference in older fuel without ethanol vs. fuel with 10% or more ethanol. Im sorry, but I must have misunderstood. Luckily, there were no issues.
As far as the knock sensors go, they are a wonderful safety tool. However, don't think for a second that they will save an engine from beating itself to death. The knock sensor can pull out the timing to help stop knocking, but as a consequence, the egt's shoot through the roof. That then makes the engine more susceptible to detonation, which takes out more timing, which raises the egt's, which makes it detonate more, which raises the egt's, which........you get the picture. Ultimately, you will just melt the pistons when the egt's get consistently over 1600 deg. There are no complete failsafes in a Merc engine, or any other engine for that matter.
Do yourself a favor and pump the gas out. You will wish you had when those new engines take a crap.
Eddie

45SS

It was more like 9 months old. It was 93 we pulled the engines. The new engines were set up to run on 91. I had no problems before they were pulled. We added more 93 to it before we ran them , and being new motors I have not yet beat the hell out of them. As the other guy said, the most common problem with fuel is that the refineries are not sending fuel that is up to it's proper octane knowing that adding ethnol will increase it's octane (ALL MERTO CITIES). I have done a lot of research on this subject. I GOT A BAD LOAD OF LOW OCTANE FUEL AND HAD TO PUMP IT OUT. Eddie has the pictures of the shifted around head gaskets.

stevesxm

so that's your answer ? that you have 9 month old fuel instead of a year and that the refiners are selling you junk anyway ?

so your ultimate conclusion is to put fuel that you suspect is weak out of the pump, on top of fuel that you already know as weak when you put it in and is now old as well ?

how you treat your equipment is up to you and your thought processes and decision making processes are your own as well. but to suggest to someone that they take year old fuel that they have poured all manner of sht into and then run that thru their NEW motors is plain stupid.

i would be VERY interested in overhearing that conversation that you have with eddie after you burn a piston as to whose fault it might have been

Young Performance

If I told him that it was ok to run it, then I would stand behind my decision if it broke. If it would have burned a piston, then I would put it between 2 pieces of bread and ate it.
My decision to run it was based solely on the fact that it was 93 octane, non ethanol fuel. There is a big difference. There also wasn't very much there and it was completely topped off with new fuel accounting for what I understood to be about 75% of the total. Combine that with the fact that the engines really only need 89 octane (we run 91 for a safety margin) and I saw no problem with it. That only holds true for this particular case. I made my decision based on what I knew. Every situation is different and should be handled on an individual basis. There is no blanket answer for what should be done. Every one is different. Hope that helps clear up any confusion.
Eddie

stevesxm

you are a very very smart and extremely clever guy, eddie and i suspect your clients are VERY well served.

Escape Velocity

This thread is enlightening and concerning for a northern Michigan boater that only runs between Memorial Day and Labor Day. Every year I have some 9 month old fuel left in the tank that's had Star Tron added to every fill-up all through the summer and then Stabil green added at winterization. Fill it full at the beginning of summer and all has been well. Maybe not in the future?

stevesxm

not if youre smart . if its injected, you put a some dry gas in it and some marvel mystery oil and run it for a bit so all that stuff gets in the injectors and then , if it were mine, i would get all the fuel out of it i can. 9 mos is , for me, the limit i would want fuel kicking around that i then intend to run thru a motor that makes any real power or has any meaningful compression ratio.
i mean, really... why take the chance ? it's not like you are on a desert island and you need every ounce to get home. when spring comes you put a few gallons in, then pump it out so it carries the condensation away , and put fresh fuel and away you go... a potential issue instantly turned into a non issue.