Two stroke fuel

[fivefishes]

Hello all,

I'm sure this question's been asked 100 times but, how long is considered too long to keep both premixed 2 stroke fuel and plain unleaded fuel before it starts to "go off". FYI i'm talking about in a plastic fuel tank in a garage not out in the elements. I've disposed of about 100l of premixed within the last 6 months cause i haven't been 100% on it, by the way disposed of means a mate of mine ran it in his Hilux (yeah yeah i can hear you all laughing and wondering how far he got), it appears as though small top up's were ok but a full tank 60L stuffed it for a while. Anyhow advice or thoughts are appreciated.

Matt

[Hamish73]

a guy I know on another forum (dirtbikeworld.net) who is an oil specialist, says premix will last just as long as standard unleaded.
If its in a sealed plastic container it should be good for 3 months or more.
I has some premix in my KTM300exc , and I fired her up last week for the first time since january with no problems. I changed it anyway because it is only 10 litres, but it still looked and smelt fine when I drained it.

[Outsider1]

Hi Matt,

there are quite a few threads on this subject. Try searching on "Stale Fuel" or similar. Here are links to the more recent ones;

http://www.ausfish.com.au/vforum/showthread.php?t=114659&highlight=stale+fuel

http://www.ausfish.com.au/vforum/showthread.php?t=124364&highlight=stale+fuel

http://www.ausfish.com.au/vforum/showthread.php?t=121087&highlight=stale+fuel

http://www.ausfish.com.au/vforum/showthread.php?t=117684&highlight=stale+fuel

The short answer is premix has the shortest shelf life, probably 6 to 8 weeks seems to be the consensus, no more than 3 months. Getting rid of it in batches in a petrol vehicle was also probably the best disposal method. There are some additives and management practices that can help minimise the problems. Happy reading!!;)

Cheers

Dave

[Outsider1]

a guy I know on another forum (dirtbikeworld.net) who is an oil specialist, says premix will last just as long as standard unleaded.
If its in a sealed plastic container it should be good for 3 months or more.
I has some premix in my KTM300exc , and I fired her up last week for the first time since january with no problems. I changed it anyway because it is only 10 litres, but it still looked and smelt fine when I drained it.

Hi Hamish,

that's interesting. I did some extensive searching on the subject a few weeks ago in one the threads I posted above. The petrol companies seem to be silent on the subject, and the only comments I could find were mower retailers and the like that sold 2 stroke motors. If we could find a counter view It would be interesting.

I don't think that anyone doubts that fuel deteriotiates over time, it is just the shelf life period that seems to contentious.

Cheers

Dave

[fivefishes]

Dave,

Ta for those threads seems the questions been asked a lot more than 100 times.BTW i'm not being tight about the value of the fuel but i'd be an idiot to throw it away if it's gunna be fine, 6 month old O/B i don't want to risk crap fuel.

Matt

[Outsider1]

Hi Matt,

I am assuming from your opening post that your tank is 60 litres or so in capacity. If you are adding fresh fuel, say a least half, and what is already in the tank is no more than 3 months old, then I would think you would be pretty safe.

Beyond 3 months I would empty most or all into a vehicle to be sure and use fresh fuel. Alternatively add 2 + 4 fuel conditioner to each batch (at the time of mixing when the fuel is still fresh). They reckon it will last up to 12 months with the conditioner in it. A bit of Fuel Doctor every other tank will also help keep your tank clean and clear of any fuel bugs and water, and help clean up any varnish, gum etc in the motor.

Cheers

Dave

[fivefishes]

Dave,

A sensible man would assume a 60l tank, yet no. I run 2 x 25l tanks and had about 10l at home in a bucket, hence the 60l into the hilux. I go offshore a bit up here and never know where i'll end up so often take 50l and only use 10-20l, i've already picked up on not premixing the spare 25l before heading out, then i get extra life out of that but the fuel doctor stuff sounds interesting, i'll check it out.

Others might say only take what you need or go fishing more often etc etc, but i'm Mr Carefull after nearly running out of fuel on maiden voyage offshore, scary.

Matt