Ethanol in petrol

[michaeln]

There have been some posts relating to running problems with petrol outboards under the electric outboard thread so I thought it might be worth opening a new thread for this issue.

When collecting my chainsaw last week from my horticulture equipment supplier I was alerted to the increasing problem of moisture absorption in pumped unleaded petrol. This results from the inclusion of ethanol in pumped fuel and his recommendation is not to use any petrol that is over three weeks old in any 4 stroke or 2 stroke equipment.

My horticultural equipment supplier is now stocking Aspen ethanol free petrol for his commercial contractors. They are prepared to pay extra for this petrol rather than have their equipment damaged. This link has more information:

http://mooresmowers.co.uk/moore_horticulture_170216_014.htm

I then contacted my Tohatsu dealer and asked about ethanol-free petrol. He confirmed he had encountered countless problems arising from a higher ethanol content in pumped petrol this year. Accordingly he is now recommending using ethanol free petrol in outboards or to use a fuel stabiliser with pumped petrol.

Petrol quality maybe worth considering when encountering running issues.

[Andy Dingle]

Indeed Michael. I hear lots of stories on the same issues with fuel amongst the local fisherman's fraternity - mostly small beach launched boats with outboards.

I use this stuff -

http://sta-bil.co.uk/product/sta-bil-marine-fuel-storage-stabilizer-236ml/

It is a little pricier (about £13 - £15) than others you can pick up in motor accessory shops, but it is allegedly specifically for marine engines and I haven't used any where near a full bottle yet.
The dealers say it's not necessary and don't recommend it, but for the relatively small amount of fuel I use, and hence the time it takes to go through a tank full, I think it's got to be worth it against the price of repair .. or the engine conking out when you really need it. I always run the carburettor dry after every use as well.
But then I'm just paranoid about engines, inboard or out. Hate them!

[Michael Rogers]

A certain member of Teifi Boat Club - which hosts Gareth's splendid Cardigan rallies, and is just down the road from Swallow Boats, sorry, Yachts - with whom I have sailed even though I can't remember his name, is a retired senior member of a now defunct Department of Automotive Engineering at Southampton University. An otherwise genial and laid back character, you should have heard him when petrol (and diesel) additives were mentioned. 'Steam out of ears', 'blistering' are descriptions which come to mind. Completely ruining good fuel, marketing con tricks.... etc etc. I don't know whether this ethanol business is recent (the impressive denunciation I heard was three years ago), but I know the reaction it would provoke in that informed quarter.

Will do the sale of Lehr propane outboards no harm, though.

[garethrow]

Andy / Michael

You make some good points. I do worry about fuel quality as I use very little, (less than 5 litres / year) but his means it sits in the can a long time. I will endeavour to get hold of some of the fuel stabiliser that yo recommend - though currently their web site appears to be down.

Michael - I suspect you are referring to George Bazely at the Teifi Boating club but don't know for sure?

Regards

Gareth
Gwennol Teifi S17

[Michael Rogers]

Yes, Gareth, indeed it was George. My apologies indirectly to him for not being able to remember his name. We had some happy fellowship over two Rallies.

[SteveWD]

Water gets into fuel from the atmosphere. The vapour in the space above the fuel in the tank expands when the day is warm, expelling vapour through the tank breather. When the day cools it sucks in air, which contains moisture. The moisture is then absorbed by the the fuel.

If th tank has a permanently open breather, minimise the amount absorbed by minimising the vapour space - i.e. keep the tank as full as possible. If the tank is portable, close the breather screw when not in use to prevent the tank breathing in air - no moist air, no water.

[Salix]

This is also a problem in the eastern USA where I live and the gasoline contains ethanol.  The firm that serviced my outboard returned it filled with racing quality gasoline which does not contain ethanol because of this problem. 

Race fuel is not that widely available though so my own precaution is to put the contents of the fuel can into my car tank at the end of a sailing trip (on top of a nearly full tank of fuel) and buy fresh at the start of the next one. I also empty the outboard fuel tank for the winter.

[Graham W]

The Aspen 4-stroke alkylate petrol that Michael mentions in the first post to this thread is tempting, despite being 3x more expensive than garage-bought unleaded.  It seems to be particularly suited to people like us who use very little outboard fuel and are nonplussed when stale fuel causes carburettor problems.

Here's a link to Aspen that also includes a UK dealer locator http://www.aspenfuel.co.uk/products/environmental-fuels/aspen-alkylate-petrol/aspen-4-alkylate-petrol/

It has been suggested on another forum that Aspen 4 is also a 50% cheaper alternative to Coleman white fuel for multi-fuel cooking stoves.

Has anyone actually used Aspen 4 in an outboard or stove? I like the idea of being able to use the same clean fuel in both pieces of equipment.

[Graham W]

Answering my own question, I've now tried the Aspen 4 petrol in a multifuel stove with better results than with Coleman Fuel (white spirit).  I've also had my Mariner 6hp outboard tuned to run on Aspen so that in future I will avoid blocked carburettor misery, caused by ethanol in garage-bought petrol.  Thumbs up on both accounts.

[Andy Dingle]

Interesting stuff. Thanks Graham. I have several dealers quite close to me and I think I'll try this stuff this year - as I'm about to dispose of about another 10 ltrs of standard fuel which I give to my friend for flushing and cleaning use on his 'antique' engines he tinkers with.
You refer to having your 6 hp Mariner 'tuned' to use the Aspen fuel - any idea what this entails?
I'm about to take my Merc 6 (same engine I believe) in for servicing shortly so will need to speak to the mechanic about this...
It's got to be worth the price - even at about 4 times the price of standard as I use so little and Mercury are not in favour of using additives that I currently use.

Thanks

Andy

[Graham W]

You refer to having your 6 hp Mariner 'tuned' to use the Aspen fuel - any idea what this entails?

Andy,

Sorry, I don't really know.  I just read that because the fuel has less rubbish in it than unleaded, the tuning might need a bit of a tweak, which is what I told the mechanic.  I assumed that otherwise the engine would run a bit rich.

[Andy Dingle]

Thanks Graham ..  It's beyond me too. I'll do what you did and actually take some of the fuel up to him and let him play when I take it in for the 'compulsory service or your warranty will be invalid' con.
I'll report back at the end of the year!

[Matthew P]

I notice that the February edition of Practical Boat Owner has an article on how to clean an outboard motor carburettor.  After careful study my personal conclusion from this is Graham is right - pay an expert to do it! 

Matthew
BR20 Gladys

 

[Peter Taylor]

I actually did a day course in outboard maintenance and we stripped down a motor of the Tohatsu/Mercury/Mariner variety. It included the two most likely problems - replacing a damaged impeller and cleaning a blocked carburettor and it convinced me that there was no chance of me being able to fix either whilst on the water and, if not on the water, getting someone else to do it is money well spent!

The other thing I took away from the course was it''s worth buying one of the funnels which allow petrol through but not water. Water can get into the petrol while it's in the filling station tanks;  also if the funnel keeps out water it should keep out fine dirt particles.

With regard to the additives, a Honda generator I bought a couple of years ago (not for the boat) came with a free service pack which included a bottle of Honda branded petrol additive which they recommended to use because the petrol in the generator would likely sit around for a time. However, for longer term storage they did recommend emptying the petrol tank and draining the carburettor.

Peter

[maxr]

Diesel bug bad, ethanol petrol bad. So propane it is, unless you think they can mess that up too. How much is a pair of oars?