A topic that as to be settled

[troy]

This is my situation regarding fuel.
In July this year i did what members advived me to do regarding stale fuel and i drained my fuel tank.
I was going on holidays so i refuled #the my boat and put in 200 litres.
I only used half of that and the next time i went out was September and i put 39 litres of fresh fuel in the tank.
Whether bad again and i have 120 litres in the tank.
Question is do i dispose of the fuel or just top it up.
I Have talked to a lot of boaties up where i live and they tell me the opposite to what members say on this site.
Confused
Troy

[snapperm8]

how old is the fuel? And if there is 120 litres i would say just top it up mayb try put some octane boost in it that u get?

[Chimo]

I'm with Troy on this Is "old" unleaded fues of more of a concern in newer direct injection motors than the old oil injected two stokes?

What does old fuel do to motors ?

Why not just use it in the boat?

Thanks

Chimo

[Decimator]

all ive ever done is put fuel conditioner / octane booster in the tank. hasnt failed yet.

[BilgeBoy]

Ok...this may help....not that I am an expert on fuel!!

I use as much as I can out of the boat between trips. Get yourself a hose and pump some into ya mower tin and into ya car... if its petrol yeah.

The fuel will actually stay ok for quite a while....bit of a how long is a piece of string question...but should be ok for several months. If you live in a really humid place...you can get some water condensation in tanks (especially under floor metal tanks)...1/4 cup of metho can help to disperse the water in the fuel so you don't get splutters etc. Just a word of caution here if you are running a modern EFI job!! But for older 4 & 2 strokes etc ...it will work just fine.

I was a mechanic for many years and I have drained the tanks of cars that have been sitting for months and months...and it's fine. If it was older than six months old...I would be draining.

Megsy

[Roughasguts]

Okay heres the risk.

Fuel older than 3 weeks starts to lose it's octane.
So you could guess that fuel 6 months old has lost a lot of it's octane.

The risk to the motor is pinging, or Detonating, which means the fuel rapidly explodes before it's suposed to even fire.

Now this detonating stuff puts a hell of a load on your pistons, cranks, and rods.

And when it has had enough, something lets go BIIIIIG Dollars.

In a car you can tell when it's detonating, shudder through the wheels or you can hear it., breaking down.

A two stroke is very hard to pick if it's detonating, and if your not sure you may give it more power, unlike the car when you would back off.

Of course giving the outboard more power increases the risk of your motor going bang.

[Chimo]

So is it correct to assume its less of an issue in the older oil injected 2 stroke motors ?

Chimo

[Roughasguts]

So is it correct to assume its less of an issue in the older oil injected 2 stroke motors ?

Chimo

Maybe more of a problem with the older models.
As the newer ones may have anti knock sensors.

But all the same, I wouldn't risk a new motor either there over 15K for a new one, what's a tank of fuel in comparison.

[Kerry]

Dilution with new fuel is basically a waste of time, sounds good but doesn't achieve much at all.

The other options are save a few bucks or risk blowing big bucks, the choice is yours, the decision is yours, the dollars are yours, the risks are yours and no point asking the same question over and over again as the answer does not change.

[youngfisho]

Will never be settled. #No one can really no for sure when the fuel is going to go off. #How long has the fuel been sitting in the station tanks before you got to it. #Maybe fueling up close to a port or near a servo that sees a lot of use (might ensure that there has been a good turn over in new fuel stocks). #Before heading out, try to guage how far you are going. #Maybe over compensate 30 percent in fuel load. #In case the weather turns bad.

Another point is how much does it cost to condition a tank of fuel say for twin 200 litre tanks. #If they have been sitting for weeks in the hot sun on the hard and one is concerned about off fuel. #

Also the amount of fuel you are carrying. #Ie if your fishing mud in your 21 footer then maybe its not so important to carry 250 litres of fuel.

These are just some suggestions. #

Does anyone know of a tool/device for measuring fuel quality at home?

here is a link to a site which has a product which is apparently quite good for cleaning and improving fuel quality by eliminating water and fuel organisms !!!! to improve the running of any engine. Maybe that would work. Never tried it and dont endorse it, just though if someone had or knew of this product then maybe it would help rejouvenate stale fuel.

http://www.liquideng.com.au/products.html


andrew

[Stumpy-USA2]

The main problem with old fuel is that the petrolium in the fuel will break down and gum up your carbs. or injectors depending on the type motor you have causing fuel starvation and fouling of plugs. This is mostly a problem during the winter months if your boat sits for more than a few weeks. I never run my tanks empty to avoid sucking any sediment in the bottom of the tank into the fuel system. I always leave about 5 gallons in the tanks and when I fill up I add Stabil or Seafoam, or whatever fuel stabilizer is available. In all the years I have run a boat I have never had a fuel related problem. The best thing to do is on your last trip out for a while add some fuel stabilizer to the tank before you go. Then when you get back add enough gas back to properly mix in another bottle of stabilizer. The fuel will be treated properly and can sit in your tank for as long as three or four months or until you go out again. I have a friend who lives in Green Bay Wisconsin, the lakes ice over every year, and he garage stores his boat for up to five months with no problems doing this.

Casey

[troy]

I would never risk blowing my motor up over 120 litres of fuel.
The first time i drained my tank was for this reason snd my son used the fuel which was 5 months old and he never had a problem.
I am aware this issue has been raised a lot of times but some members will say eg after 3 weeks they drain there tanks .
In my case i would be draining my tank all the time as i do not know when the next time i will be going out.
This is why i raised this again and i know the answer will not change and i am sorry if i am annoying anyone.
I Always use premiun unleaded and i asked the servo how long was it not safe to use and he said at least 6 months but then again he is selling the fuel.
Troy

[subzero]

Taken from Yamahas FAQ page

https://www.yamaha-motor.com.au/ssl/index.htm?marine_faq.asp

Fuels

ETHANOL BLENDED FUELS

OUTBOARDS

Q. Are Yamaha outboards motors, 4 stroke and 2 stroke, designed to operate on Ethanol Blended Fuels.


No, All current and previous models are NOT designed for Ethanol Blended Fuels at any percentage. (ie. E5, 5% and E10, 10%).

If Ethanol Blended Fuels are used you may experience driveability and running problems, fuel component deterioration and damage due to moisture.

PERSONAL WATERCRAFT (PWC's)

Q. Are Yamaha PWC's 4 stroke and 2 stroke, designed to operate on Ethanol Blended Fuels.


Year Models prior to 2000 are NOT designed to operate on Ethanol Blended Fuels. Year Models 2000 and after are desogned to operate on Ethanol Blends at a maximum of 10% (E10)


1. Will my early model Yamaha outboard run okay on standard unleaded petrol (91 ~ 93 ron)?


Yes! All Yamaha models, from the early 1970's have been designed to operate on lead free petrol in the octane range of standard unleaded.(91-93 ron).


2. Will I cause any damage to my outboard if premium unleaded or high-energy fuels are used?


No. However, if you encounter any running problems as a result of using such fuels, change back to standard unleaded (91-93 ron).


3. Fuel Notes

With any fuel, ensure you obtain it from a reliable source, and that the fuel used is always fresh. Stale fuel can damage an engine.

[subzero]

Taken from
http://www.faqs.org/faqs/autos/gasoline-faq/part3/section-2.html

8.6 What is "stale" fuel, and should I use it?

"Stale" fuel is caused by improper storage, and usually smells sour. The
gasoline has been allowed to get warm, thus catalysing olefin decomposition
reactions, and perhaps also losing volatile material in unsealed containers.
Such fuel will tend to rapidly form gums, and will usually have a significant
reduction in octane rating. The fuel can be used by blending with twice the
volume of new gasoline, but the blended fuel should be used immediately,
otherwise teh old fuel will catalyse rapid decomposition of the new,
resulting in even larger quantities of stale fuel. Some stale fuels can drop
several octane numbers, so be generous with the dilution.

[subzero]

Would I use stale fuel, dilute the fuel? No, mechanics charge to much money.
Cheers Lloyd

[perko]

We have lots of troubles in the small engine side of our business with fuel going off. Mowers sit around all winter and half of summer with the droughts. You can smell the varnish smell a mile away when it is bad and they won't fire on it. We are trying the Briggs fuel conditioner which makes fuel last 2 years if put in when fresh and at the right dosage. Might be a bit dear for boats by the size of the fuel tanks they have though.

[troy]

Subzero,
Thanks for that.
One interesting thing is that when i picked up my boat they told me if i could afford premiun unleaded it was the way to go.
Thanks
Troy

[Homer_Jay]

Just a couple of questions.

How many of the hundreds of people on here have ever had a problem with blowing pistons from using old fuel?

What is the length of time everyone on here keeps fuel for?

Does it make any difference if its premium or regular?

Does it make any difference if it has an additive? (i have to use an additive cause my sterndrive is supposed to run on leaded)

Does it make any difference if it is premixed?

I dont profess to be an expert and I dont really have any of the answers.
All I can say is that I have always used fuel for a long time (up to 6 months) in my old premixed outboards. Since I have been a member of this site I have realised that there is a problem and now I am very cautious of the problem. I now make sure I drain if it is over 2 - 3 months and I always use premuim.

[Kerry]

No, All current and previous models are NOT designed for Ethanol Blended Fuels at any percentage. (ie. E5, 5% and E10, 10%).

Then regardless if one can afford premium or not that statement also eliminates premium as many of the premiums now have blended ethanol and there is no requirement to advertize this fact or what % at the bowser either.

Regards, Kerry.

[troy]

Might be dumb here but they say outboards and pwc,s.
What do they mean.
Also is my 175 hpdi okay using Premiun unleaded.
Troy.
Are they referring to jet skis pwc,s.
They state it okay to use premiun i thought by using it and paying dearer for it was better for my motor.

[Deiter]

Troy. yes, pwc - Personal Water Craft or something like that. jet skis basically.

[troy]

Okay fess up,
Honestly how many of you have had your fuel for say 2 months and used it.
I have any more.
Troy

[Chimo]

yes me too

Chimo

[blaze]

me too

[Roughasguts]

Me too. But I top it up by about double with Pulp.

[Alex9797]

Hey Troy,

you''ve got a nice boat , live in a great place.............


get out a bit more and you won't have a problem ;D ;D ;D ;D

cheers

Alex

[troy]

Alex,
I would love to and will get out more often but my type of work does not allow me to choose when i can and this is where i get caught in this fuel situation.
Thanks for the compliment on my boat.
Troy

[PinHead]

I have not emptied the fuel tank in my boat and hopefully never will (means I will be stuck somewhere)..a few weeks back was the lowest it has been...still had 50 litres in it therefore I am always running a blend with new and stale fuel...there has not been a problem.