PDA

View Full Version : How long can I leave fuel in a tank before it starts to go bad? Advice please



quobbarockhopper
25-12-2014, 07:28 PM
Hi all

Just a fewquestions about the old fuel that’s been sitting in my tank for a few months Iwas hoping you guys could give me some advice on…

My boatsbeen sitting dry for about 3 months due to being away at work and crappyweather when Ive been at home. It’s a 150L tank and has about 25-30L left. Theoutboard is a Yammi 150 4 stroke with 56 hours. Obviously (and especially)being so new I don’t want to do anything harmful to it.A few questions aboutthis:

- is 2-3months long enough for the fuel to degrade/ separate etc?

- Will theapprox. 120L of new fuel Ill be putting in before her next run be enough tonegate any deterioration etc that may have happened to the old fuel that’s inthere?

- Is thereanything I could add to the existing fuel to freshen it up?

-Am Ibetter off just figuring out a way to drain the tank and disposing of the oldstuff all together? If so, any advice on how to do this? It’s a Yalta 555.

Cheers inadvance for any advice

Anthony

scorpo92
25-12-2014, 07:40 PM
I think theres a product called stabil thats a fuel reconditioner

Spaniard_King
25-12-2014, 07:50 PM
Stabil will not recondition old fuel!!!!.. it is designed to lengthen the life of good fuel.

Moonlighter
25-12-2014, 07:54 PM
Anthony, the question you pose is a little bit more complicated than it might appear.

In hot northern Qld climates, fuel seems to go off quicker than further south - it can happen in as little as a month or so. Since you don't state you location in your avatar we can't tell where you are. (It's a good idea to add your location)

Also, full tanks seem to last better than ones like yours that have only 20% left. Fuel stored in full sealed containers like jerry cans lasts better than tanks with open breathers.

I have seen and smelt unleaded that is off. It doesn't smell fresh like normal gas, it has an almost sulphur like rotten egg type of whiff to it.

If if yours has even a hint of that, drain it out. There is no alternative.

Fuel that has already gone off is like milk that has gone off, it can't be revived or refreshed regardless of what some people will try to tell you. Add fresh milk to rotten milk - all you get is a bigger lot of rotten milk. Petrol is the same.

Stabil and the like are intended to keep good gas from going off, not revive bad gas.
Petrol that has gone off is bad for engines. Pre-ignition can occur and burnt Pistons result.

If if in doubt ........

captain rednut
25-12-2014, 08:27 PM
These days treat petrol like you do milk in your late model four stroke and you will be safe and if it doesn't smell like its giving you a head rush dont use it.

Darren Mc
25-12-2014, 09:39 PM
I reckon if you didn't treat it with stabil, etc last time you filled it, to be on the safe side, drain it out. It's only 20 or 30 ltr's. Fill it with fresh stuff and definately use stabil or what ever your choice is of fuel treatment from now on.
It'll cost a little extra to buy the treatment, but then you know your fuel will be good if you don't use her for a while again. I like the peace of mind thing.

Fed
26-12-2014, 05:35 AM
Fill it up & go fishing.
http://www.bp.com/content/dam/bp-country/en_au/media/fuel-news/petrol-life-vehicle-tanks.pdf

scottar
26-12-2014, 09:21 AM
In a lot of years of using unleaded fuel, with layoff periods of up to 6 months at a time due to work commitments, I have never had regular unleaded go off. In some of my small power equipment, premix fuel would go anything up to 12 months before being used. If you have filled with E10 though it could be a different story. Could be a different story if you have any water in your tank too. I would have a quick check as some of the others have said via a sniff at the filler, then fill her up and go fishing

PaulyB
26-12-2014, 04:58 PM
Just Had my old 2 stroke 135 Merc major over hauled (pre mix).
Mechanic has advise me to go 98 octane and not to use E10 as he claims the E10 has a very short shelf life.
Also I have heard the the Army/Air force do not use E10 only 98 octane.
My opinion, dump the 30ltrs. Worth about $36 not worth the hassle if it fouls up.

quobbarockhopper
26-12-2014, 05:29 PM
cheers guys. Im probably going to drain it, but would like some more advice on how to... Im thinking about using an electric fuel pump and a hose, tilting the boat back to push all the fuel to the back of the tank (near the fill point) and doing it that way... would this be the best to go about it?

Im by no means a mechanical guru, so could anyone recommend which type of pump to get and approx. how much $ this would cost? (no to fussed on how quickly it would pump but am thinking if theres no major price difference between a strong and weak one it could come in handy at some stage when filling the tank from jerry cans when Im staying at fishing camps etc out bush)

thanks again

kizza1
26-12-2014, 07:07 PM
Certanly not worth draining. just add 50% or more of fresh stuff and there wont be a problem.
i have fixed many fuel systems plagued with old fuel but never one with 6 month old or newer fuel. water yes but not old fuel.
old fuel has a very distinct smell. it doesnt smell like petrol.

Darren Mc
27-12-2014, 01:36 AM
Mate, just do what your gut is telling you to do. It's not that much hassle and which ever way you decide to go, do what put's your mind at ease.
What some of the guy's are saying about just fill her up is probably fine, but there's no harm in being a little over cautious either.

Bremic
27-12-2014, 04:41 AM
cheers guys. Im probably going to drain it, but would like some more advice on how to... Im thinking about using an electric fuel pump and a hose, tilting the boat back to push all the fuel to the back of the tank (near the fill point) and doing it that way... would this be the best to go about it?

Im by no means a mechanical guru, so could anyone recommend which type of pump to get and approx. how much $ this would cost? (no to fussed on how quickly it would pump but am thinking if theres no major price difference between a strong and weak one it could come in handy at some stage when filling the tank from jerry cans when Im staying at fishing camps etc out bush)

thanks again

You can syphon it using the existing fuel hose to your motor, you just need to make sure the hose hangs below the level of the fuel tank, pump the priming bulb and it will all drain out. You may need to run the fuel hose out of the scupper or bung hole to get it low enough, no need to go and buy your self a pump. If you tip the boat up as mentioned, you will get it all out except maybe a few litres. I wouldn't worry about that if it is mixed with 120l of fresh fuel.

Fed
27-12-2014, 06:08 AM
From a practical point of view and if you have easy access to the tank you will be better off buying a few metres of fuel hose & connecting it to the take off point at the tank then syphon it out.

Getting enough height can be a problem, last time I did it I had to lay the jerry can on its side then slowly rotate it to its edge and now with a new trailer that sits lower I think I'd have to first jack the whole trailer up then tilt it as previously described.

tug_tellum
27-12-2014, 09:58 AM
Not trying to Hijack this thread, but how do you dispose of 30 litres of fuel without doing damage to the enviroment? We used to just pour it around the fenceline to kill weeds but I think that is kind of unacceptable now. There are places to dispose of used oil but I havent seen anywhere that takes bad fuel.
Mick

LittleSkipper
27-12-2014, 10:28 AM
Goodness gracious me! You've only got approx 25-30 Litres of not really that old fuel out of a 150 Litre tank, just go and fill up the tank with fresh premium unleaded and take it for a good long run. All this talk of draining fuel that's only 3 or so months old is really not necessary.
If the fuel had been sitting there for 12 months or more then that would negate draining it but not 3 months.

If your using premium unleaded it has a longer lifespan than most people think.

Sent from my iPad using Tapatalk

mitc69
27-12-2014, 11:27 AM
had fuel sittin for 6mth before, just top it up and all is good, never had problems :)

quobbarockhopper
27-12-2014, 11:35 AM
tug: yep, I live in a country town so I just usually go and pour it in the river or in the turtle nesting beach up the road....

THATS A JOKE before people start getting upset...

A friend owns a servo up here, he has an overflow/ waste tank that I will be depositing it in

back2boats
28-12-2014, 09:31 AM
If your using premium unleaded it has a longer lifespan than most people think.




The problem is, that's NOT what the fuel companies are saying. I have read about times as short as a month being problematic, and it's hard to figure out just how much topping up is necessary to keep the fuel sitting in a tank fresh enough.

I have purchased a smaller tank for my little outboard, just to increase the % turnover of fuel per trip.

LittleSkipper
28-12-2014, 09:48 AM
The problem is, that's NOT what the fuel companies are saying.

I see your point but I didn't mention anything about fuel companies.




Sent from my iPad using Tapatalk

Darren J
28-12-2014, 10:38 AM
A friend owns a servo up here, he has an overflow/ waste tank that I will be depositing it in

I imported a boat from then US, much to my surprise it arrived with FULL. Lets say the wife's late model car ran really well for about the next 400+ litres worth of fuel, and I spent quite a few hours with syphon hoses hanging of the tanks. It takes a long time when draining through the fuel lines. I would estimate that fuel would have been 8 months+ old by the time it was all used. There is no way I would be dumping your old fuel. It would at the least, go in the car, lawn mower etc even if topped up with fresh Premium. It will be used in no time at all that way. The car (assuming it is typically driven) is also not a "high revving" engine like a boat engine, so those concerns should be minimal. I think the wife's car would be lucky to hit more than 3000rpm on a typical drive.

Personally, for 30 litres or 20% tank capacity remaining, I would mix down with premium as others have suggested, particularly after reading the BP bulletin and getting some understanding of how the fuel state changes.

Biggest concern, you add another 100 Litres, don't get a lot of use and in 3 months for some reason have 80 litres of old fuel in the boat.

Best bet, go fishing more often!! don't let the fuel sit.

kizza1
28-12-2014, 06:33 PM
I have read about times as short as a month being problematic

i think this would be in regards to a high compression or boosted "performance" engine. ie the sort that will only run on 95 or higher tuned to the max. i dont believe that this would happen on an outboard.
just run it. mix in a bit of fresh stuff and there wont be a problem.

dnej
28-12-2014, 11:55 PM
Don't take the risk. Also do a search on this site, there is some previous information, worth reading.
Anything over 45 days has stated to loose its worth. People recommending other wise, are giving the incorrect advice. sorry guys.
I have actually seen it written in operation manuals as well.
David

Fed
29-12-2014, 06:54 AM
Outboard manufacturers would be happy to have us do a full service every trip including new fuel & battery.
People are already brainwashed into replacing water pump impellers, fuel filters and wheel bearings on an annual basis and now it's 3 Month old fuel.... Make it stop!

tunaticer
29-12-2014, 07:36 AM
jeez this old chestnut resurfaces a lot!

Do a search to find my answers.

juggernaut
29-12-2014, 01:49 PM
I ran 12 month old BP 98 fuel in my modified Nissan S15 when i was having it retuned after being modded - made 390 rear wheel hp and revved to 8,000. No such problems with detonation, pinging or the like. I still only drive it ocassionally and most of the time has a least 3 month old fuel in it - revved to 8,000 every time i take it out.

Out of interest - do modern 4 stroke outboards have knock sensors?

JulianDeMarchi
29-12-2014, 02:20 PM
cheers guys. Im probably going to drain it, but would like some more advice on how to... Im thinking about using an electric fuel pump and a hose, tilting the boat back to push all the fuel to the back of the tank (near the fill point) and doing it that way... would this be the best to go about it?

Im by no means a mechanical guru, so could anyone recommend which type of pump to get and approx. how much $ this would cost? (no to fussed on how quickly it would pump but am thinking if theres no major price difference between a strong and weak one it could come in handy at some stage when filling the tank from jerry cans when Im staying at fishing camps etc out bush)

thanks again

I have a new hilux fuel pump which I drained the tank on my 555 with. Worked fine, but took 30mins for 60ltrs.

I'm with the others though mate, you've only got what you think is 30ltrs left. Open the fuel cap at the rear, smell. If it doesn't smell like stinky rotten eggs, fill the tank and go fishing! Just remember to ask your mate at the servo for a good discount... :)

LittleSkipper
29-12-2014, 04:28 PM
Outboard manufacturers would be happy to have us do a full service every trip including new fuel & battery.
People are already brainwashed into replacing water pump impellers, fuel filters and wheel bearings on an annual basis and now it's 3 Month old fuel.... Make it stop!

Couldn't agree more


Sent from my iPhone using Tapatalk

dnej
29-12-2014, 10:30 PM
So the marine mechanics, and the fuel companies, and the manufacturers, and the technicians, are all wrong. Well OK then
David

fishing111
29-12-2014, 10:41 PM
I'm with the others on this one as well as I have used older fuel, sometimes over 6 months and haven't had any issues. In sayin that I'm not saying it can't happen, and i'll just have it on me if something goes a wry. Sometimes we take things to the extreme, i mean in my manual it says to pull the prop off before flushing, how many of us do that every time, not me.

kizza1
30-12-2014, 09:34 AM
heres a question for those that would drain it. do you think boat yards that have a boat on consignment for 3months drain the tank before someone buys the boat? and if so who pays for it and where do they dispose of that fuel?

you could be talking upwards of 2000 litres a month if this was the case.

the answer is no. they top the tank up. then they run the engine under load on a watertest and send it out.

if its been in there 12months or more then it would be drained.

juggernaut
30-12-2014, 09:57 AM
So the marine mechanics, and the fuel companies, and the manufacturers, and the technicians, are all wrong. Well OK then
David

Where do fuel companies say drain your tank? The BP link recommendations were to top up the tank, keep more fuel in the tank, use a better fuel and/or change your plug heat range.

Every mower, edger, blower and whipper snipper of the average bloke should have blown up by now if you hadn't tipped out the old fuel after 3 months. Yet this intermittently used high revving equipment lasts for years....often with neglect. How is an outboard different?

Darren Mc
30-12-2014, 10:00 AM
Yeah and boat yards always do the right thing by customers. Most of them are probably no different to car yard salesmen.

Darren Mc
30-12-2014, 10:07 AM
It's a bit different to have to repair or replace a mower or blower than an outboard worth up to 30 - 40 grand though don't you think. Not worth risking in my book.

I use fuel treatments religiously in all my petrol using toys so I don't have to worry about this very problem, except for my cars which get used every day.

juggernaut
30-12-2014, 12:45 PM
Cost is irrelevant, the fact is this equipment doesn't need replacing or repairing because of three month old fuel.

Darren Mc
30-12-2014, 01:03 PM
To you maybe,not me.

stue2
30-12-2014, 02:10 PM
Just put 45km on my 12 month old fuel. 190 lt tank topped up with 80 lts of premium. Been doing this for 25 years unfortunately not able to use the boat during the year because of work. If I'm lucky i get a fish over easter but that hasn't happened for a few years.
Had some trouble with water once but that was quite a while ago in the old boat. Don't have that trouble in this one.
Cheers
Stu

Darren Mc
30-12-2014, 04:58 PM
I was'nt trying to say you'd have to replace them or repair them from using 3 month old fuel. But problem's can arise from using old fuel one way or another. I would choose not to risk it in my outboard as it cost me a lot more than my blower or mower etc. Once in a while might be ok but what happens over time if you lose track of how long it's been between trips and how many times you topped it up.
Could it potentially cause unseen damage over time that you don't know about until something finally let's go on you one day when you least expect it.
You could be in a lot more trouble than standing in you're back yard holding you're blower in your hand thinking oh sh!t.
It's such an easy thing to avoid so why risk doing it.
Hey, if you think it's ok that's cool with me it's not my outboard on your boat.

I just think unless you use your boat regularly,use fuel treatment in your fuel so it's not an issue.

dnej
30-12-2014, 05:41 PM
Below are some comments from a boating company in Victoria on the dangers of using stale fuel highlighting the seriousness of running stale fuel in an outboard motor.



I have harped on about fresh fuel and good quality oil (for 2 strokes) for a very long time.

Unfortunately, we all have a bit of a mindset when it comes to petrol. We don't want to toss it out because it costs "so much".

Our perception (probably as a universe!) is that petrol is very expensive. BUT, people will pay $1 per litre or much more for BOTTLED WATER, $2+ for a litre of Skinny milk, $24 MINIMUM for 3/4 (50mls less) of a litre of Bourbon and so on it goes...

Sure, we don't use as much of these other products as we do fuel but it is a moderating thought.

The mental mindset of not discarding your boat fuel based on what it cost is what costs people much much more when their engine shits itself.

Stale fuel is a VERY bad thing but people generally do not understand that. They often think its the mechanics "excuse" for why their marine engine died. They need to understand the fuel lifespan and usage constraints.

If you need to lay your boat up for a few months and particularly if it has an underfloor tank which has a lot of fuel in it, then apply a fuel conditioner whilst the fuel is fresh and it should still be usable when out of hibernation.

But over and above that, fuel management is the key.
.................................................. .................................................. ................

An engine can run very easily when it is "free running", ie: no load. Unfortunately, a no load "all ok" is often reported and followed by a "won't run under load" scenario.

juggernaut
30-12-2014, 07:16 PM
Here's on old post from Spaniard King - and as I thought, the knock sensor will kick in a modern 4 stroke.

troy,

From experience, basically if it smnells like fuel use it.. if it smells like varnish toss it. The worst thing stale fuel will do to your honda is make it run rough until it gets good fuel !!!!!

If the fuel is "real"bad the engine will start and the knock sensor will take over and stop the engine if needed, but you will be able to start it again, this is how you can identify the fuel is bad if you ever get to that scenario.

Poor fuel aquaints for many 2 stroke issues but varry rarely causes isues in 4 strokes as they either run or not.

Link post #17.

http://www.ausfish.com.au/vforum/showthread.php/169216-Stale-Fuel/page2

JulianDeMarchi
31-12-2014, 08:03 AM
Who leaves their boat so long that fuel goes bad anyway? ;)

Fed
31-12-2014, 08:27 AM
Last Australia Day my Missus broke the top of her leg off, had to get a new one so My boat sat there for 10 Months with half a tank.
I topped up with new fuel a Month ago & took it out for a run so now I'm left with a 1/4 tank of 11 Month old fuel & a 1/4 tank of 1 Month old fuel all mixed up together.
What's that, 1/2 a tank of ~6 Month old fuel?
It will be another Month before I start using it again so when I top up I'll have a full tank of 3 Month old fuel, I'll slowly get back to the 'best before' date.

Easy to do with a dirty old OMC V4 dinosaur but if I had a stressed out HiTech $$$ motor I maybe would have considered draining the tank at nearly a year old... or not, maybe I would have gone for a gentle cruise to burn off the fuel instead of dumping it.

fishing111
31-12-2014, 11:56 AM
deleted, found manual

mutineer
31-12-2014, 07:21 PM
Besides gumming anything up old fuel won't do any actual damage to a motor ..it doesn't lubricate it burns in Burn cycle , top it up and go ...it only loses efficiency .. my opinion only , but my tinny is lucky to get wet 1 or 2 times a year top up and it's fine anyone thinks petrol does anything else then let mehave it , oil in 2 stroke is a different story it lubricate s ..

Spaniard_King
01-01-2015, 01:28 AM
Besides gumming anything up old fuel won't do any actual damage to a motor ..it doesn't lubricate it burns in Burn cycle , top it up and go ...it only loses efficiency .. my opinion only , but my tinny is lucky to get wet 1 or 2 times a year top up and it's fine anyone thinks petrol does anything else then let mehave it , oil in 2 stroke is a different story it lubricate s ..

Well you have a lot to learn then!!

old fuel can cause a carby 2 stroke to detonate resulting in a catesgrophic failure (spelling eludes me at this time)

Yes you can add new fuel to old, but who will stake their reputation on it? not I too many fuel related failures to do that

good night and Happy New Year

juggernaut
01-01-2015, 09:04 AM
Not sure how old it is but found this article which has a wealth on information re causes of marine engine failures:

http://www.marinesurveyor.com/boatpokers/data/piston.pdf

mutineer
01-01-2015, 10:14 AM
Lol Spaniard ... Yes I'm aware of real old fuel , but a few months hardly calls for a line drain filter change carby drain episode ... if anyone has legit happen ed to them evidence then I would be happy to hear it ...I personally have never seen nor heard of any ..and I know it's bad practice but I don't run anything out of its fuel , because corrosion and dry seals cause just as many theoretical problems ... my opinion only

jeffrey_h
08-05-2015, 03:54 PM
My 35 lts of unleaded petrol was not much over 12 months old so I emptied it all out, inc lifting the 130 lt tank out as well.
The highlight was the colour of the old, RED, compared to the new near clear. There was never any oil added.
2 stroke Mercury EFI 2006 200 hp. Actually got an electric mower, so no. Ford 2005 4.0 lt. What would you do?



Thanks
Jeffrey

Back In Black
08-05-2015, 04:03 PM
Mate, whatever you do, don't fill at the Liberty Noosaville across from the boat ramp.

Your stuff looks great compared to the filth I was sold!!

Tony

Chimo
08-05-2015, 04:37 PM
Tony

Maybe you could respond as invited with a review?

https://www.facebook.com/LibertyNoosavilleServo


http://www.localsearch.com.au/Noosaville,QLD/Liberty-Service-Station/profile/VHsf

(http://www.localsearch.com.au/Noosaville,QLD/Liberty-Service-Station/profile/VHsf)

Back In Black
08-05-2015, 05:55 PM
Tony

Maybe you could respond as invited with a review?

https://www.facebook.com/LibertyNoosavilleServo


http://www.localsearch.com.au/Noosaville,QLD/Liberty-Service-Station/profile/VHsf

(http://www.localsearch.com.au/Noosaville,QLD/Liberty-Service-Station/profile/VHsf)

Done!! And felt good too

myusernam
08-05-2015, 08:06 PM
I once had to be towed back with one tank full of fuel like that. It was shxt. 130l of puss. I primed the lot out with the bulb waiting for it to get good. I even jumped over the side to see if i had holed the hull and contaminated the tank. No just shxt fuel. darwin on way back from tiwis.. Alex O if you are reading this. thanks heap bud

fisho64
09-05-2015, 12:33 PM
3 months-just fill it up and use it, unless of course you have foolishly used Ethanol blend in it at some stage though we dont have much of it in WA.
If it has E10 in the tank get rid of it!

Fed
09-05-2015, 01:09 PM
3 months-just fill it up and use it, unless of course you have foolishly used Ethanol blend in it at some stage though we dont have much of it in WA.
If it has E10 in the tank get rid of it!
That fuel is now about 2 1/2 Years old.

TheGurn
09-05-2015, 07:30 PM
So new fuel won't refresh old fuel. I get that. But if you use 20% of a full tank when you go fishing, and top up on the way home, and do this every 3 or 4 weeks, some of your fuel in the tank will inevitably be 'old' after a few trips (months). Some will be in there for much longer. So it must be alright to use well diluted old fuel. Hope so.

Cheers
Reg
Sent from my HTC Wildfire using Tapatalk 2

back2boats
09-05-2015, 09:03 PM
So new fuel won't refresh old fuel. I get that. But if you use 20% of a full tank when you go fishing, and top up on the way home, and do this every 3 or 4 weeks, some of your fuel in the tank will inevitably be 'old' after a few trips (months). Some will be in there for much longer. So it must be alright to use well diluted old fuel. Hope so.


This happens, even in the tanks at the service station itself. They top up the tanks before they get completely empty, so even there, a certain (small) % of the fuel is old.

MyWay
09-05-2015, 10:32 PM
this is what the fuel and fuel tank looks like if you do not use motorbike for one year

Dogtoooth
10-05-2015, 04:47 PM
I use 98 octane shell for my Df90a since new. I have a external 100 ltr poly tank, and if I don't use the fuel in a month I pump it out, and put the old fuel into a gerry for the ute. I haven't had a problem yet. Every month I change the old fuel to be safe. Dogtoooth.