Ethanol vs premium

[PugetSoundBoater]

I drain my portable fuel lines once a year at the end of the season, to avoid pumping old gas (even though it’s ethanol free with Seafoam or OMC4+2) into my winterized motor in the spring.
In the spring I drain whatever gas is in my 6 gal plastic tanks ,and from condensation and temperature changes,yep there is a bit of water in there. I get it all dried out by wrapping a piece of paper towel wadded taped securly around a stiff wire and tilt the tank up and swab it out. Leave the tank with the lid off in the sun. Shine a flashlight in there to be sure I got all the water out. Nice clean tanks and hoses for the first outing.

"Some people want to know how a watch works, others just want to know what time it is"
Robbie Robertson

[jerry-ahrens]

Beerman, to answer your question, it’s an aluminum bowl. Those pictures are pretty crappy, but it did have some rust along with a gooey coating all over everything. Never have saw one quite like it. Maybe the ethanol is not to blame? maybe he added a bunch of different additives to cause this problem, I’m not sure.

[20mercman]

I had a neighbor bring over a 4hp Evinrude a few weeks ago that he said would not run. I took the carburetor apart, and it looked just like the photo Jerry posted. I removed the integral tank, and found classic phase separation in the fuel. It came out like brown mud, but if left to sit in a clear clean glass jar, it would settle out and clear up. The water layer was about 30% of the mixture. I am sure if you Google "phase separation", you will find photos of it. I have run it in my newer motors when I didn’t have a choice, but I don’t keep it around and don’t put it in anything older than 1971. Even then, I find my 800 runs much better on pure gas. Smoother idle and easier starting. Not just imagining it, it really makes a difference.

Steve

[jerry-ahrens]

Steve, I have a 165 Mercruiser 6 cyl. in my service boat. Great old engines and they run forever. I have the distributor dwell and timing set perfectly, along with a rebuilt carb with perfectly set idle mixture. This engine runs perfect on ethanol free fuel. However running on the ethanol blend, it stalls after a warm restart, and needs one more start before you can put it into gear and go.I run service calls with this boat, so it sets for 30 to 45mins. between jobs. At first i thought i had a problem somewhere til I switched back to to ethanol free gas, then the problem instantly was gone! I’ve tried this a few times back and forth, with the same results. The old 165 doesn’t like ethanol, and runs great on pure gas. I had a similar situation on my Ranger bass boat that sits too much… my 150 OMC V6 is hard to get started after setting on ethanol…. fires up fine on pure gas. These tests were enough to convince me.

[shoestringmariner]

20Merc and Jerry, is this an ethanol blend without fuel stabilizer?

[Tubs]

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

• This reply was modified 6 years, 5 months ago by Tubs.
• This reply was modified 4 years, 1 month ago by Tubs.

[flathead]

Tubs, does ethanol make the problem worse? To me it seems to be much worse in the stuff I run. Not just outboards, but my lawn mower, chainsaws, etc.

[Tubs]

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

• This reply was modified 6 years, 5 months ago by Tubs.
• This reply was modified 4 years, 1 month ago by Tubs.

[outbdnut2]

Here’s my 2 HP on the subject: For those of you in Minnesota, the only ethanol-free gasoline is premium because the Minnesota Street Rod Association lobbied the state legislature when they were going to totally outlaw gas without ethanol. Premium is what the Street Rods and a lot of collector cars needed, so that’s what we have. I’m just glad we have something that’s ethanol-free, and that’s all I use in all my boats, small engines, and a couple old cars. I’ve seen ethanol in gas turn old rubber gas lines to mush, and I saw the phase separation in my neighbor’s inboard tank after sitting all winter, and the gas tank was under the floor – not removable to empty it out!
–
What I don’t understand is why the Sta-Bil gas stabilizer in the non-ethanol version is marketed in Minnesota at all???? You have to go out of your way to find "sta-bil-ethanol" treatment here. I found auto parts store counter guys who give you a blank look of not understanding when you ask for sta-bil ethanol. Note that "sta-bil marine" has twice the amount of the chemical that prevents phase separation in ethanol. I called the Sta-Bil company when sta-bil ethanol first came out to see if it eliminated any other ethanol-related problems besides gasoline storage issues (their ads were vague on this), and it does not. I’m getting tired of explaining this to friends and neighbors who bring me their small engines and outboards to fix!
Dave

[Pete]

Back in muy young years in our outboards Dad always used regular in days of leaded fuel with no E in it. When I raced in APBA (1970’s) I used Amoco or Sunoco regular. Now I use 87 E free in the outboards, it’s available in the Orlando area. Standard Fuel station gas (87, 89, 93) have essentially the same energy available (BTU/pound), the octane difference is from the additives to get the anti-knock ratings and other stuff (some propitiatory) they put in there for cleaning, etc, so if the engine doesn’t need the higher octane premium will do nothing more than regular, but it will not hurt the engine just your wallet. Octane additives will change the burn time profile of the fuel, higher octane results in slower burn time.

See here for more detail:

http://www.factorypro.com/tech/tech_tun … power.html

If you determine the compression ratio of the service 2 cycle engines related to the top of the exhaust ports (not the full cylinder volume as used in 4 cycle engines) which is when the compression gasses are fully sealed from escape they are in the 6.5:1 range thus octane requirements are not that high and 87 will suffice. Even my race engine (Merc 25ss and Yamato) are in that range and run great on 87 E free.

Unless the old engine is properly modified for E fuel try to get the E free for no water issues in the fuel even if it’s the premium and the engine doesn’t need it.

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