Run Gas Out of Outboard?

[sdowney717]

If you simply add water to E10 gas, then shake and let set, the gas will phase separate, with alcohol-water mix on bottom and PURE gasoline on top. This will drop the octane a couple of points.

Thing is, if you buy mid or high octane instead of regular, add water, then pour off pure gasoline, you will have at least a regular rated pure gasoline grade to use.

So you dont have to buy aviation gas.
I do that with my lawnmower engines. Will work for small outboard engines also.

For lawnmowers, they have low compression ratios, so this works fine even starting with regular phase separated gas.

You lose 10% of your gas since it is E10.

 

[Peter B]

Can you not get unadulterated 98 octane, (sold as premium petrol here in Oz), without the ethanol..? Ethanol blend comes out at only 94 octane, and many new cars,especially from Europe need 98. We have no trouble getting ethanol free fuel. I always get 98 octane for things like outboards mowers etc anyway because the octane drops off over time, and fuel for those tends to sit around quite a bit.

 

[bayview]

I have only experienced one FI outboard stored after only water flushing flushing for a year with ethanol gas. It was hard to start and ran poorly until fresh gas got into the system. If I had it to do over I would find a way to empty the system. I always wondered what was happening to the injectors and pump with that junk in them.

IIRC I flushed the rail by venting at the schrader valve.

It did not seem to suffer any ill effects but my experience with running a two stroke dry was always better.

 

[psneeld]

The only time I left ethanol in my 8hp 2012 yamaha for more than a few weeks, it barely ran.

Took apart the carb 5times cleaned it the best I could....still ran rough but better.

Had one of the mechs soak it in carb cleaner overnight with 2 cycles of the ultrasound cleaner going .... finally ran normal.

You can only get ethanol in some US states, and if you follow a few simple rules (which I didn't once) and it is rarely a problem.

You still have other issues that regular gas has too...so ethanol is only incrementally worse....it's not the demon it is made out to be.

In the old days, I am pretty sure some of us ADDED alcohol based fuel additives to clean fuel systems and remove a little water....manage E-10 and it's not so bad.

 

[Ski in NC]

The difference between EFI and carburetor engines sitting is that the EFI fuel system is basically sealed and the gas has little opportunity to evaporate or contact oxygen. In a carb, both evap and oxygen contact readily happen. That's what degrades the fuel.

I have seen many many examples of EFI outboards that have sat for 6mo to over a year with fuel system full of fuel. Hit the key and fires up just fine.

Do the same with a carb engine and you better whip out the tools.

Regarding ethanol fuel, keep the water out and sump the tank periodically, and it causes no trouble. Problems start when water is not controlled. This is assuming the tank/engine parts are compatible. I run regular ethanol gas in the few things I run that are not diesel. Have not had trouble.

 

[bayview]

Ski are you saying e10 won't separate in a closed FI system?

 

[Ski in NC]

Ski are you saying e10 won't separate in a closed FI system?

The presence of water is what drives separation. If tank and system are kept free of water, then separation should not be an issue.

 

[smitty477]

"I have only experienced one FI outboard stored after only water flushing flushing for a year with ethanol gas. It was hard to start and ran poorly until fresh gas got into the system. If I had it to do over I would find a way to empty the system. I always wondered what was happening to the injectors and pump with that junk in them."


FWIW - I have had more than a few FI outboards and we need to store them for more than a few months here in the NE. When I do the winterizing and when I remove the fuel filters for replacements I disconnect the normal fuel line to the tanks - then temporarily attach a portable 2-1/2 gallon fuel tank with ethanol free gas and storage additives of your choice and concentration - prime and run in fresh water so all fuel is ethanol free and stabilized during the flush process. Per the manuals (Yamaha and Suzuki in my case) I do not release the pressure on the fuel rails but I then do drain the evap. tanks as per manual.
Replace fuel line back to the tank with the normal stabilizer in there as well.
Been doing this for quite a long time and they start up immediately each season and run with no affects.

 

[ranger58sb]

You can only get ethanol in some US states...

You meant "You can only get NON-ethanol in some US states..." yes?

As I mentioned, Av-gas and the little cans at Home Depot could be an alternative... but I've never seen those at any of our marine fuel docks.

-Chris

 

[bayview]

I probably would have done what Smitty says but this was an unplanned long storage just normal after use flushing.

 

[catalinajack]

I have 3 small outboards, all late model 4 strokes. I run the gas out of them any time they will be stored (like between trips). If you don't, you will eventually have clogged jets from the gas sitting in there. Mine always start and run perfectly as long as I don't leave fuel in them.

The larger outboards are likely fuel injected and this probably doesn't apply to them. If it has a carburetor, you will have problems if you let the fuel sit in there over time.

JD[/QUOTE

I have a Yamaha 25 carbureted four stroke. It started right up last spring after sitting all winter, about five months. It sat another four months before being statred again. Neither time was it run dry. Yes, the jets can gum up if using ethanol gas. I don't. Its the ethanol that's the problem. Talk to Senator Grassley (Iowa) about it. He's one of the primary political maintainers of welfare for farmers - the ethanol subsidy. Democrats or Republicans. They're all harlots in the end.

 

[BruceK]

Can you not get unadulterated 98 octane, (sold as premium petrol here in Oz), without the ethanol..? Ethanol blend comes out at only 94 octane, and many new cars,especially from Europe need 98. We have no trouble getting ethanol free fuel. I always get 98 octane for things like outboards mowers etc anyway because the octane drops off over time...

South of the border we can get 91 octane unleaded, as distinct from the ethanol blend. I buy diesel, not gasoline, but I thought our higher octane gas was 95. Our second car, a Hyundai I40, definitely develops more power on 95 and uses less of it, but can run on any grade.
Ethanol producer Manildra, seems to have the ear of Govt, so how long we have non ethanol fuels is debatable.

 

[Peter B]

Bruce, as of now, in Queensland, we can readily get non-ethanol 91, 95, and 98 octane petrol, (gas, for the USians), and E10, (effectively 94 octane), which does end up the cheapest, and actually my 1990 GT4 turbo loves it, but then it never sits around long in the tank. Much as they may want to increase the E10 share of the market, as so many late model cars prefer 98, or 95 octane as a minimum, I can't see us not being able to get ethanol free fuel for the indefinite future.

 

[BruceK]

Peter, E10 is usually cheapest at the pump but tests I`ve read and some experience suggests it yields less distance traveled. I buy 91 or 95 no ethanol, for the outboard, and the machines to combat the tyranny of grass.

 

[Art]

For 2 stroke or 4 stroke small engines; o/b's included:

I mix "Berryman B-12 Chemtool" at 1 oz per 6 gallons gasoline for general running purposes.

https://www.berrymanproducts.com/pr...-carburetor-fuel-system-and-injector-cleaner/

If there ever becomes some roughness in motor's idle or upper rpm range (which I do have happen every couple years) I simply give the gas a 1 oz to to 1 gallon Chemtool hot-shot. Been doing this for decades - Chemtool really keeps motors running well regarding fuel line circumstances!

I do not run my engines dry before letting them sit for up to 6 + months. If the span will be well over that range then I do run them dry.

 

[Peter B]

Peter, E10 is usually cheapest at the pump but tests I`ve read and some experience suggests it yields less distance traveled. I buy 91 or 95 no ethanol, for the outboard, and the machines to combat the tyranny of grass.

Quite true, it is less energy dense, so mpg, (using the old units) is a wee bit less, but the 94 octane means most modern engines, especially turbo'd, like the higher octane, and it is sufficiently cheaper than the 95 or 98 octane one would otherwise use to more than compensate for the slight loss in mileage. Besides, it smells nicer.

 

[BruceK]

Now now Peter, no petrol sniffing, or you`ll be restricted to "Opal"fuel.

 

[Peter B]

Now now Peter, no petrol sniffing, or you`ll be restricted to "Opal"fuel.

I meant the exhaust smells better...aaaagghhhh.

 

[ranger58sb]

The larger outboards are likely fuel injected and this probably doesn't apply to them. If it has a carburetor, you will have problems if you let the fuel sit in there over time.

Reminds me of something else I've thought about: carbureted one-cylinder outboards seem to have more trouble with ethanol than carbureted multi-cylinder outboards. Just a theory, but it seems I read folks with 2- and 3-cylinder models seem to have fewer issues than we did with the 1-cylinder carbureted 2-stroke.

-Chris

 

[bayview]

Chris: From what I have read the ethanol reduces the lubrication provided by the oil/gas mix causing engine wear.

 

[ranger58sb]

Chris: From what I have read the ethanol reduces the lubrication provided by the oil/gas mix causing engine wear.

Interesting, hadd't thought of that, but...

A few times, with the carbureted 2-stroke, at only starting levels of throttle, it seems like the engine would race, then almost stall, race, then almost stall, repeat several times...

As if fuel octane (or something?) was momentarily increasing or decreasing.

I remember wondering at the time if it was maybe burning alcohol (race), and then gas, and then alcohol (race), and then gas... due to phase separation in progress. I'd imagine if there were periods where it was trying to run on alcohol, that'd be pretty much devoid of lubricant...

-Chris