Pre Mix fuel how long does it last?

 I wonder if any one could advise how long it is ok to pre mix 50/1 fuel. A mate said six months but im not sure you can keep it that long? Do i need to add in some fuel additive? Thanks for any help much appreciated

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Jewskip


Feral's picture

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 if you think it's started to

Fri, 2017-09-22 20:02

 if you think it's started to go off you can just top up the tank with a fresh mix.  I've used it up to 6months with no issues but much after that I'd pour in half a tank of new fuel into the old stuff..  Be aware some oils will separate out of the fuel over time, it's more important to ensure that the oil is still mixed in 

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Date Joined: 17/06/10

Be aware that some oils are hydroscopic

Fri, 2017-09-22 20:35

Some oils will absorb oil and any moisture that accumulates in the tank can be absorbed by the oil in the two stroke mix. That is why if you are going to keep two stoke fuel make sure that the container is filled right to the top so that there is no space for moisture to accumulate and if the fuel is over 3 months old.

I would do what feral has suggested top it up with new fuel or to play it safe put the old fuel into your car and fill the tank with fresh fuel. Being out in the wide blue yonder and having fuel problems is not the way to enjoy a day on the water.

duncan61's picture

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Date Joined: 21/11/14

fresh

Fri, 2017-09-22 23:48

 Always make fresh 2 stroke as fuel and sparks are all that can go wrong.Why risk a high performance engine with dodgy fuel,Put it in your lawn mower or wipper snipper.I am calling a month on stored 2 stroke and then \I would shake the tank up a lot before using.If it is a large motor like a 200 etec and the oil is seperate it is not such a big deal.I use 91 as it is a slower burn you dont need high octane rated fuel in a 2 stroke and never use Ethanol based dual fuel it will gum up even large 2 strokes and potential damage the engine

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just do it.

Shimka's picture

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Date Joined: 06/02/14

 Not exactly the same but

Fri, 2017-09-22 23:50

 Not exactly the same but I've run 40:1 that was way over a year old through my MX bike before no problems at all. Plenty of dirt bike riders have with no issue. Moisture in 2 stroke is not much of an issue really. Petrol motors are far more forgiving of moisture in fuel, not like diesels. If you're really worried about it either chuck in 100ml of metho per 20 lt or stop being cheap & just dump the fuel & buy more.

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I have come to realise the "diarrhea of the mouth" is a direct side effect of "s#%t for brains". The best defence is to slap & run.

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metho and two stroke oil

Sat, 2017-09-23 05:59

Be aware some two stroke oils will jell if mixed with metho, which is Ethanol. most fuel additives use propyl alcohol. If you have a petrol vehicle , use it in that, the oil will be diluted and do no harm,

Shimka's picture

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Date Joined: 06/02/14

 Have you ever actually done

Sat, 2017-09-23 10:33

 Have you ever actually done it Marrisy? Because I have, many times & there was no geling/congealing of any sort. 

Yep, that's another alternative, chuck it in a petrol vehicle & it will burn no problems. Maybe a little smoke for a bit but at 50:1 it won't be much, if at all, unless you 1/2 fill the tank with the two stroke.

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I have come to realise the "diarrhea of the mouth" is a direct side effect of "s#%t for brains". The best defence is to slap & run.

Posts: 138

Date Joined: 08/09/11

yep. manny times.

Sun, 2017-09-24 17:30

and have had the occasional problem with a carby blocked with gell. Metho will pull water out of the atmosphere.
look up alcohol phase separation, interesting read.

Shimka's picture

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Date Joined: 06/02/14

 Don't need to look it up,

Sun, 2017-09-24 19:49

 Don't need to look it up, I'm reasonably familiar with the topic. If you have had issues with moisture getting drawn in then you should store your fuel better & keep your tanks full when you're not going to be using the car/boat/bike or whatever for a while. That will stop the moisture problems you have experienced. In my 41 years I've spent 35 years on bikes, boats, using chainsaws etc & performing my own maintenace for at least 25 of those years. I've never experienced an issue or even heard of anyone else having one. Technically it is possible but in the real world, it really shouldn't happen unless you are neglegtful of your fuel storage. 

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I have come to realise the "diarrhea of the mouth" is a direct side effect of "s#%t for brains". The best defence is to slap & run.

Posts: 138

Date Joined: 08/09/11

fair enough,

Mon, 2017-09-25 08:55

In my 63 years, including running an engine rebuilding business, I have seen plenty of engine damage, corroded carbys and carbys full of jelly. I raced motorbikes ,gokarts, speedway, have had boats all my life. guess you have been lucky. And we shouldn't hijack the OPs post. regards Marrisy.

Shimka's picture

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Date Joined: 06/02/14

 Fair call. Cheers Marrisy.

Mon, 2017-09-25 10:46

 Fair call. Cheers Marrisy.

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I have come to realise the "diarrhea of the mouth" is a direct side effect of "s#%t for brains". The best defence is to slap & run.

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Date Joined: 27/05/12

I have 65 liltres to ehther

Sat, 2017-09-23 07:29

I have 65 liltres to ehther use or get rid of. My car is diesel if idecide to dump it how do i get rid of that much fuel? Thanks again for your thoughts guys. Might just start a fresh rather than risk it in my new custom tank arround 70 litres.

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Jewskip

Shimka's picture

Posts: 435

Date Joined: 06/02/14

Big bonfire. Give it to a

Sat, 2017-09-23 10:37

Big bonfire. Give it to a friend with a petrol vehicle (explain what it is & that they should only add 10lt or so per tank), use it in your mower etc if you use them. Another possibility, though you would have to talk to the staff, is that Supercheap have free oil disposal bins. You may be able to dump it in those if they allow it but again, I'm not sure about that so check with the staff first.

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I have come to realise the "diarrhea of the mouth" is a direct side effect of "s#%t for brains". The best defence is to slap & run.

Poppy's picture

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Date Joined: 19/01/13

Yamaha 4 Stroke Fuel

Sat, 2017-09-23 11:44

 I have a near new 40hp Yammy 4 stroke and have been running it on 91 octane.  It performs very well (I love the motor) on the standard fuel, but wonder if any advantage would be gained on 95 or 98 octane.  Would welcome any views on this please.

 

Bazza

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A pessimist is never disapointed

duncan61's picture

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Date Joined: 21/11/14

octane

Sat, 2017-09-23 18:38

 As most are aware Octane is a measurement of the detonation point of fuel.lower compression engines can run anything,My jeep ran harder on 98 and went about 50 km further per tank.The major issue is running high compresion engines on lower rated fuel.However 2 strokes seem to run better on low Octane which I believe has a slower burn rate as well.

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just do it.