How long does mixed fuel last?

[H-A]

I am not sure what the reason for fuel going off is, is this a new thing.

 

I realise that the more volatile fractions will evaporate, thus reducing the octane value, and the ethanol content will absorb water.

 

Other than that what else is going wrong.

 

How does this degradation effect the combustion in the cylinder to give seizing problems.

 

I would have thought that the saw would run less well with stale fuel, but from what I am reading, old petrol kills saws.

 

I am surprised that the oil manufacturers do not mix a stabilising additive in the oil.

 

Is the "stale fuel used" term, being wrongly accepted as an excuse for premature cylinder failure.

 

Perhaps I need to revue my "cost of Aspen" thoughts, if there is a definite answer to fuel degradation claims.

 

Does Aspen have any volatile components that evaporate in periods of little or no use?

 

H-A

[GardenKit]

Pump petrol contains around 100 different chemicals and is, by its nature "chemically unstable". Basically, it has chemical reactions take place within itself from the time it leaves the refinery. These chemical reactions cause the chemical structure to change, creating some new chemicals and destroying some of those originally present.

 

around 35% of pump petrol is made up of solvents, which are highly volatile and gas off, leaving behind the concentrated gums and resins which were formed in the chemical reactions and which are responsible for 'gumming' carburettors. In addition, the chemically changed petrol becomes acidic and starts to attack plastics, rubber and even alloys.

 

The 5% ethanol rapidly absorbs moisture and deposits water in the tank and carburettor

 

The changed petrol has lost its energy level, so in effect there is less petrol content in the air/fuel ratio which causes the mixture to become weak, resulting in hot running and eventually a lean sieze.

 

The stale petrol also rejects the 2 stroke oil and pushes it out of suspension. It does not fully recombine even with a shake, so engine lubrication is compromised.

 

Briggs and Stratton Fuel Fit will to some extend slow down the chemical deterioration by reducing oxidation which is the main chemical reaction.

 

Aspen has only 10 chemicals and is "stable", i.e no chemical change. It has no solvents so is less volatile, but equally combustable. The oil will stay in suspension indefinately.

 

Plus, there are other benefits too, such as being less harmful to the operator.

 

As regards "stale fuel used" being used as an excuse for failure. It is wrong to blame stale fuel for every failure. There are other causes that need to be investigated. But stale fuel is nevertheless a very major factor which is overlooked by many.

 

In short, keep your fuel fresh, treat it with Fuel Fit, or better still, use Aspen.

[Woodworks]

Excellent explanation Barry Thanks

 

I understood that the fuel looses it's energy but did not know this would in turn cause damage. I will look into Fuel fit.

[H-A]

The 5% ethanol rapidly absorbs moisture and deposits water in the tank and carburettor

 

I have just been reading this, http://www.nfahc.co.uk/pdf_files/ethanol/ethanol%20in%20petrol.pdf

 

Looks like the premium brands of petrol contain no ethanol, but this could be out of date.

 

I generally buy the super petrol for my saws, but am now thinking about "date batched" label on my combi can.

 

When I find a place selling Aspen I will give a can a go.

 

H-A

[Gareth Dalzell]

Fuel turn over isn't a concern for us but what is a concern us those machines we don't use so often the big saws. Should we be draining them and running them dry?

[Eddie@aspen]

I have just been reading this, http://www.nfahc.co.uk/pdf_files/ethanol/ethanol%20in%20petrol.pdf

 

Looks like the premium brands of petrol contain no ethanol, but this could be out of date.

 

I generally buy the super petrol for my saws, but am now thinking about "date batched" label on my combi can.

 

When I find a place selling Aspen I will give a can a go.

 

H-A

Hi, email your post code or check the Aspen website as we are adding new dealers every month if not every week!!!

 

Let us know how you get on with Aspen

 

Kind regards

 

Eddie

[GardenKit]

Fuel turn over isn't a concern for us but what is a concern us those machines we don't use so often the big saws. Should we be draining them and running them dry?

TBH, I am not a fan of running them dry.

The carb diaphragms will tend to dry out and harden, and they do not always rehydrate well.

Petrol residues and gum will harden and block jets etc.

 

I would rather store them wet, but ensure the fuel is kept fresh.

 

If thats not possible then Aspen is the ideal fuel to use.

[div_h]

After reading this thread and the poor guys sob story I ditched the fuel out my saws,hedge trimmer and the jerry can that filled them and the colour difference between them all was surprising.

[Gareth Dalzell]

TBH, I am not a fan of running them dry.

The carb diaphragms will tend to dry out and harden, and they do not always rehydrate well.

Petrol residues and gum will harden and block jets etc.

 

I would rather store them wet, but ensure the fuel is kept fresh.

 

If thats not possible then Aspen is the ideal fuel to use.

 

Thanks.

[Wood wasp]

I'd be interested in trying Aspen but even buying 200l drum it's more than twice the price (albeit you have to buy the two stroke oil also for forecourt stuff)… But I have to buy 200l Aspen up front to get lowest price.

 

200l is 44 gallon so not even two months worth of cutting, I could use normal stuff and just buy a new saw every 6 months with the "saving" by not using Aspen.

 

So… I'm interested but it's seems simply too expensive.