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Ethanol fuel damage

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Merco 6131/03/2015 12:49:31
55 forum posts
19 photos

I,ve just collected my garden machinery (2 stroke and 4 stroke) from service.The man alarmed me.He told me that pump petrol now contains a high percentage of ethanol(alcohol) which,as we know,attracts water and has a detrimental effect on petrol itself and some engine components. He sold me an additive called Ethanol Shield.If,like me,you are fussy about the care and maintenence of model engines,both petrol 2 strokes and glow 4 strokes,you might find it interesting to Google the product and study the claimed benefits.If the product does what it says on the bottle,it sounds like the perfect after-run for 4 stroke glows. Apparently there are moves afoot to increase the ethanol percentage to 30% in pump petrol-supermarket grade-so perhaps we should take notice.

Levanter31/03/2015 14:21:49
894 forum posts
439 photos

Merco. A big welcome to the forum and starting with a tip not a question!

I have many four stroke engines and corrosion worries me a lot. I have rebuilt a couple of second hand ones and the corrosion is often shocking, Maybe a good test article for RCME.

Dane Crosby31/03/2015 14:28:45
255 forum posts
23 photos

Hi, this problem has been known for a while. Classic car clubs and my kit car club have all discussed the move to E10 fuel over the last couple of year. The ethanol attracts water in to the fuel which can then form acids if the fuel is not used for a time. We recommend not storing the E10 fuel for more than one month. We all had snags with the new fuel when it was found that older rubber fuel pipes and seals would rot quite quickly. Steel and copper pipes can suffer as well. I found out he hard way that the E10 petrol rots older design fuel system sealants. All filters rapidly blocked up and an expensive EFi pump ruined.

I now use the "Nitro" fuels in my kit car. Although more expensive, the additives go some way to preventing the effects of the ethanol and I suppose that I only drive it for about 2000 miles a year it doesn't break the bank. Quite a few car club sites discuss the apparent variable low quality of supermarket fuel. People in the Pajero owners club suggest never putting supermarket diesel in our trucks. I haven't seen any scientific studies either way.

Any more modern engines should have been built with the knowledge that ethanol is being added to pump petrol so the effect will not be so marked although if the fuel is left undisturbed for a length of time it will still separate and degrade. Briggs and Stratton state that their engines and tanks should be drained of petrol if they are not to be run for more than one month.

The price of progress

andyh31/03/2015 18:33:37
429 forum posts
22 photos
Posted by Merco 61 on 31/03/2015 12:49:31:

If,like me,you are fussy about the care and maintenence of model engines,both petrol 2 strokes and glow 4 strokes

any reason why just glow 4-strokes? as I understand it, methanol is even more hydrophilic than ethanol

Don Fry31/03/2015 19:00:07
4557 forum posts
54 photos

I thought that ordinary 95 RON had no ethanol. The petrol labelled as E10 has ethanol in it. The thought came from memories of reading the instructions for a 4 stroke marine outboard, and they said that while the engine will run fine on E10, only if used within a month of purchase. Thereafter lies corrosion problems due to the hygroscopic nature of the ethanol.

Am I right in believing that ordinary 95 is ethanol free.

Cuban831/03/2015 19:00:59
3163 forum posts
1 photos

Hi Merco & welcome to the club.

As the forum's resident cynic I had to smile when you said your garden machinery supplier scared you into buying ten quid's worth of Ethanol Shield (never heard of it so had to Google it).

My wife's 100,000 mile 2002 Fiesta hasn't missed a beat on Asda cheap petrol for 10 years, so although I accept what others say about 'cheap' fuel I can't say we've had any problems with it. surprise

avtur31/03/2015 19:43:25
883 forum posts
20 photos
Posted by Donald Fry on 31/03/2015 19:00:07:

I thought that ordinary 95 RON had no ethanol. The petrol labelled as E10 has ethanol in it. The thought came from memories of reading the instructions for a 4 stroke marine outboard, and they said that while the engine will run fine on E10, only if used within a month of purchase. Thereafter lies corrosion problems due to the hygroscopic nature of the ethanol.

Am I right in believing that ordinary 95 is ethanol free.

I think you'll find that all 95 unleaded is an E5 fuel, so 5% ethanol. If I remember correctly I don't think E5 fuel has to be labelled as such because it is taken as read that 5% ethanol is now the norm. E10 fuel should be labelled because not all cars are designed to run on it yet.

The issue of water being absorbed by ethanol is well documented, however I'm not sure that the problems are quite as severe as some would have us believe. I move in two circles where none-ethanol fuel would be preferred, classic cars and light aircraft. both groups are coming to terms with using E5 fuels and in either circle I don't know anyone who is experiencing severe problems because of E5.

There is a dwindling availability of E0 fuel supplied as 'premium unleaded' (98 RON). In some supplies of some brands in certain parts of the country super premium is E0, however this is dwindling all the time. On the light aircraft side of things some users are testing their fuel to check the presence of ethanol. On the basis that there are no lay-bys in the sky the effects of an unreliable engine in an aircraft are potentially catastrophic, in a car its more of an inconvenience than a life threatening event.

E-fuel is with us and here to stay, I think it is an EU issue regarding the progress from E5 to E10.

Edited By avtur on 31/03/2015 19:43:59

Merco 6101/04/2015 00:43:34
55 forum posts
19 photos

Thanks for thewords of welcome.Sorry about the breach of etiquette-should have explained that my log-in failed so had to re-register. I am happy to use the cheapest petrol available for the car and do understand the posts. I think the lawnmower man was honestly trying to warn of the possible consequences of leaving fuel in the tanks of small engine machines during winter layup,rather than mechanical damage to moving parts during normal use.A Walbro carb is a delicate device,no matter if mounted on a chainsaw or a big model aeroplane,isnt it ,so anything that might prevent deposits or corrosion forming is worth a look. I learned the hard way years ago when model four-strokes first arrived that you cannot go flying for the day and just prop the model against the wall and forget it until the next time.Recreational dismantling may seem fun but the rust on the ball races mixes well with the blood from the cuts to your fingers as you attempt to drift them out of a hot crankcase.I know that the best procedure is to pinch off the fuel supply whilst the engine is running at normal temperature,but this can be impossible if it is fully cowled.Even more difficult if you have just crashed! I took WOO,s advice.Pump out tank and then liberally flush out with a mix of petrol and transmission fluid,leave to drain naturally nose down. Now I discover that the rinse-out actually may be introducing water from atmosphere so looking for a better way.

Edited By Merco 61 on 01/04/2015 00:49:13

Andy G.01/04/2015 08:03:39
413 forum posts
215 photos

This has been causing concerns within my other hobby, motor cycling, where not only the engine corrosion issues worry us but also the effects of the ethanol on the plastics used in some fuel tanks. The current rumour mill tales are that it can lead to perforations forming. The thought of fuel leaking onto your legs whilst simultaneously dripping down onto a hot engine as you ride along is not a pleasant one!!

onetenor04/04/2015 20:42:52
1901 forum posts

Some South American countries use alcohol fuels produced mainly from sugar I believe. Surely this corrosion problem must have been overcome in those countries. If I have it wrong I stand to be corrected. With regards to Methanol fuels I have never had problems with stored fuel as long as it is tightly sealed .Also Methanol has been used as racing fuels does any one know how they treat their engines. I have always used Castor as the oil of choice in both diesel and Glow engines and never had any corrosion problems . this includes engine stored for over 40 yrs. Sticky deposits of castor but no corrosion. I have always added a few drops of 3 in 1 type of oil after a run turning the engine over a few times to distribute the oil. My oldest engine is an AMCO .87 (Looking for a carb assy for this ;or whole engine ..any condition if cheap ) This hasn't been used for over 50 yrs but shows no sign of corrosion We must be aware that even paraffin has a liking for water and that things degreased in it must be oiled quickly or rust can form almost overnight afterwards. Likewise WD 40 I think the moral is always oil up after a run. also standing an engine in nose down attitude would allow left over fuel to pool on the bearings . But wouldn't the heat of a just run engine evaporate any alcohol and water still in the residual fuel. Just an afterthought. Might the moisture come from the air condensing on cooling metal on a slightly misty evening after a days flight.. I am no expert so please make allowances for an old man. Take my advice and oil up.This should stop the corrosion.

onetenor04/04/2015 21:04:33
1901 forum posts

Just had a thought . When ,years ago, we found water in petrol tanks on cars we would add about a pint of meths ( or Methanol   to the tank and give the car a good rocking that usually cured the problem. also years ago there were fuel filters that seperated water from fuel which had to be drained regularly. Small ones were about the size of half a good sized lemon made of a glass dome and had a drain screw ( like a butterfly nut ) on the bottom .Very like the seperatorrs / filters used on compressor systems. Perhaps they are still available but i doubt if they are available in model sizes.

Charles Smitheman04/04/2015 22:10:32
226 forum posts
18 photos

I fix lawnmowers etc for a living.

Most problems seem to be with little used machines.

The incidence of water in fuel tanks has increased markedly recently. Of course I dont know what people do with their mowers, a lot are very careless. (Leaking garden sheds, or left outside)

Our nearest station is a Shell one. I have several times tested their fuel with a Briggs and Stratton alcohol test bottle, there is no alcohol in it. I have heard that some supermarket and other brands do contain alcohol.

The other thing to remember is that there is no lead in fuel anymore. So they use other chemicals to replace it. Probably different brands contain different additives. This might be part of the problem.

Older carburetters particularly on two stroke machines have rubber parts that are damaged by modern fuel.

Briggs and Stratton market an additive called Fuel Fit which is supposed to stabilise the fuel for up to three years, and protect against corrosion.

Stihl sell a super two stroke oil which contains fuel stabiliser four up to one year according to their literature.

The problem I have seen with draining the fuel is that rubber parts can then dry out and get stuck.

I believe in the mentioned products. I do not know much about the other one mentioned in the OP, I have tried a sample, but I prefer to go with the manufacturers recommendations. How do you test something like this?

On the interesting subject of glow engines I now use Bekra 10 with good results. Previously I have noticed that the engines can become recalcitrant when using up the dregs of the 5l fuel bottle. What I now do when draining the model after flight is to keep the used fuel in a separate small bottle, and use it up first at the next session. The thought behind this is that the exhaust pressure would constantly blow moist gas into the fuel tank during engine running. (moisture from the air) This could be absorbed into the highly hygroscopic methanol.

I also make a point at the end of use of running the engines warm and removing the fuel pipe from the carb to let it starve. I then also remove the fuel pressure tap pipe from the exhaust, so nothing can back flush from the tank to the engine during transport and storage. I use an offcut of brass fuel tube or nyrod inner to join the two pipes from the tank together to stop the fuel dribbling out.

Mr. Laser engines, Neil Tidey' recommended to me the use of ordinary SAE30 lawnmower oil as an after run lubricant. As it has no additives it will combine with whatever other oils are in the engine. Also four stroke oil such as this is formulated to neutralise combustion byproducts which are acidic. Just what we need. And it is very cheap too!

So far so good with the above for me anyway.


Iain Middleton04/04/2015 23:20:13
2 forum posts

In Canada we suffer from ethanol in our fuel too.

Here in Edmonton our premium grade is ethanol free.

I have been using this fuel in my model engines for the last 2 years and all the fuel problems are gone.

Except that it is more expensive than the lower grades but no problems makes that very acceptable.


cymaz05/04/2015 09:01:46
9597 forum posts
1267 photos

I use. This. In my fuel mix for my plane engines. Do I need a fuel stabiliser as well?

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