Gas question:

[Amelia]

I just made the hour-long trek to buy ethanol-free gas, all ten gallons of it at a time, and decided that was a stinky chore I would like to minimize. So: anybody know if I can burn 100LL (hundred octane low lead aviation gasoline, which doesn't contain ethanol) in our Yamaha T-60 outboards? When we take the travel time into account, it's not THAT much more expensive, and it's readily available ten minutes from home. We don't use enough to keep the ethanol stuff fresh, even with stabilizer added.

[easttnboater]

I don't see why it would not work fine. I would contact Yamaha and see what they say.

If you want more opinions, then you might want to post over on boatered.com. There is a guy over there GeeBee that is a boater/pilot that talks about sharing between his boats and plane.

[OLD HOUSEBOATER]

Yamaha requires 86+ Octane fuel contaning no more than 10% Ethanol. In other words car gas. Why would you want to spend more money and take a road trip to fill your tank with non spec fuel? You don't have modified racing engines.

From page 9 of the Yammi Manual.

[Knot Normal]

Yamaha requires 86+ Octane fuel contaning no more than 10% Ethanol. In other words car gas. Why would you want to spend more money and take a road trip to fill your tank with non spec fuel? You don't have modified racing engines.

From page 9 of the Yammi Manual.

The answer is in the first post...

We don't use enough to keep the ethanol stuff fresh, even with stabilizer added.

[OLD HOUSEBOATER]

Ok, got it now.

[Amelia]

Thanks for the thoughts! I called a Yamaha guy over at Manteo who said he didn't have the definitive official answer, but he DID know that the state ferry ops nearby had an outboard on a runabout they hardly ever used, and had continuing problems with gummed-up carburetors. He hied himself over to the local airport, bought himself some gallons of 100LL, and has had no further problems. I think we may just go with that! At $5.50/gallon, it's not cheap, but neither is $4.05 for ethanol free, an hour's drive (or 6 hours of perfect weather by homemade houseboat) away. And carburetor teardowns are really pricey. The local outboard guy thinks he has a license to steal. Bless his heart.

[Ike]

In a recent BOATUS magazine someone asked essentially the same question. Here is their response.

Avgas can be a good choice for many boaters, though there are two issues. First, avgas contains lead and cannot be used with many newer inboard and I/O engines that use catalytic converters to reduce pollution. It's likely that in a few years even outboards will employ catalytic converters. Second, avgas costs 50-100 percent more than marina gas (at the Baltimore airport it's $9.00 a gallon!). An alternative is to look for ethanol-free gasoline at local gas stations. A website — pure-gas.org — lists stations that sell it by state. Seaworthy would be interested to find out if the site is current, so if you use it, let us know.

And another member wrote:

You recently ran an article about ethanol-free gas and one person commented that he had used avgas as a replacement for non-ethanol fuel. As an aircraft mechanic, I thought I would pass along a warning.

When synthetic oils were first coming on the market, an aviation company started selling a 100-percent synthetic oil for use in aviation piston engines. It was not very long before the people using this oil started having oil pressure problems and engine failures. It was discovered that the synthetic oils could not keep the lead found in aviation fuel in suspension and it began settling in oil passages and oil pans. Currently, all aviation oils for piston engines use either a crude-based oil or a synthetic mix.

One-hundred percent synthetic oils are being used in boat and other piston engines. Since your basic automotive gasoline does not have lead, the use of synthetic oil is not an issue until the lead is introduced by way of aviation fuel. So if you are going to use the avgas in a boat, or any other piston engine, be sure you are not using a synthetic oil in it. They do not play well together.

Chip Woods
Memphis, TN

[Amelia]

$9/gal in Baltimore! Whew! THAT is why I don't buy much avgas when I fly into BWI with Angel Flight patients. Fortunately most of the parasite fees are waived for charity organizations, but for ordinary flights, they're mighty proud of their fuel, their ramp, their runway, their security theater, their tie-downs... If I didn't know better, I'd suspect they were trying to run us poor GA pilots off. But avgas is a lot less than that here in Edenton, and just ten minutes from home.

Thanks so much, Ike, for the warning about synthetic oil! I'll read the label on the Yamaha oil and see if it has synthetic ingredients. And I'll check that website to see if there's any 0-ethanol gas nearer here than Elizabeth City.

[kiohaa]

it's readily available ten minutes from home. We don't use enough to keep the ethanol stuff fresh, even with stabilizer added.

[pirate]

Non Ethanol is anywhere from a $1.99 to 2.50 within 30 miles of my place on the Tenn Tom