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Tanks and Ethanol

hangloose

New member
"Ethenal gas: I have a 25 HP

"Ethenal gas: I have a 25 HP Evenrude;
1.What type tank should I use? I understand that the wrong type of tank ethenel will desolve the tank and change it into gunk and get into the
motor. Also I heard Ethanal may delute the oil in a 2 cycle and could tear up the motor.

2. When I flush the motor after fishing, should I run the motor dry or leave the fuel in the engine.

3. When I shut down for the season do I run it dry, or leave gas in the in the engine?} Some say leaving leaving the motor dry ruins the seals???"
 
"Victor, so many questions [im

"Victor, so many questions


Most modern gas tanks are fine - so plastic (poly) tanks are excellent - don't rot/rust etc.

Aluminum tanks are also acceptable.

You want to stay away from fiberglass tanks - those are the ones that will disintegrate on you - however, unless you have a vintage boat with a built in tank that should not be something you encounter.

Ethanol up to 15% is generally safe in most motors. However, on some older models (pre-80's), the rubber in the fuel lines may be at risk for deterioration, so on older motors it's worth spending a couple of bucks at the local auto-parts supply to get a couple feet of gas hose and replace it.

Ethanol (alcohol or methanol) does asborb moisture at a far greater rate than gas. Because of that you need to take a few extra precautions when running the blended fuels.

First off, you should keep your tank as full as possible during storage. Keep the vent(s) closed and sealed tightly when not in use. If you have a built in tank that means you have a hull vent that is often overlooked - make up a rubber cap for it to seal it off as well.

ALWAYS add fuel stablizer (sold under a number of brand names, marine or otherwise).

You could install a water separating filter between the tank and the motor - and keep spare cartridges handy - more pratcial with larger motors/built in tanks, but even an "in-line" version (as opposed to a canester model) sure wouldn't hurt even on a portable. The current recommendation is a 10 micron water separating filter.

Ethanol gas gets old quickly - in as little as two weeks it's octane level drops way down. Not a problem in your car because a tank of gas rarely lasts you more than two weeks - but could take you all summer to burn a tank in your boat depending on usage. So stabilized or not, it's best to plan ahead so that you have just enough gas for what you will burn - and at today's gas prices you don't need gas to be going bad or old on you.

Alternately, if you are using a portable tank 3/5/6 gallon etc, simply take the left over gas and put it in your vehicle. Some guys would cringe at adding mixed gas to their vehicle, but I have never had an issue running it in my pick-up truck - the 2 or 3 gallons that may be left, mixed with the 20 to 30 in my tank turns that 50:1 blend into about 500:1 and my motor never seemed to mind (and my truck is only a few years old - modern injection system etc). If the motor is a 4 stroke or an oil injected model, that's not even an issue since it runs straight gas anyhow.

Running the motor out of gas when you are finished with it for the weekend or whatever is generally a good practice. It reduces the amount of gas in the carb(s) which can help prevent gumming. If you plan on leaving the motor for more than 2 weeks between uses it would also be prudent to remove the carb and empty it completely. Simply running it out of gas helps, but it does leave some fuel in the carb (and fuel filter).

On some particular "multi-carb" set-up's it is not advisable to run them out of gas - some models are fed from the fuel bowl in the top carb. Running it dry can leave you in a position where your top cylinder(s) are out of gas (and oil) while the lower cylinders continue to fire - that can be spell disaster - however, in the case of a 25 horse (single carb) that is not an issue.

You don't have to get really psycotic about ethanol fuel - a couple of simple practices and it will work well without causing issues for you..."
 
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