Aspen 4 Fuel

[AndyB]

I have a BC26 which is around 6 years old with the original engine a Mercury 9.9....  I have been filling it with standard E10 fuel. It does not gets used much unless I am against tide trying to get back to the pontoon.

Recently the engine failed to idle at an unfortunate time ( as it always happen - just as I was moving from astern to forward). The engine previously had a full service with gaskets changed etc and the servicer did point out how bad the rubbers were as engine manufacturers have not changed the compounds to cope with ethanol. He recommended I put in an additive....

After adjustments and tests we came to the conclusion that the carburetor needed replacement and since they are all the same I purchased a Toshiba one. Mercury being 3 times more expensive and unavailable for some 6 months.  This conclusion came from the semi blocked channels in the carburettor which you cannot get to with out drilling out. The standard deep cleaning to not clear them. One which we looked at had rubber compound from the carb gaskets. The engine runs much better now and it seems to me that regular replacement of the carb seems prudent - maybe every 5 years.

The real answer is to move to an EFI such as the Suzuki as they do not suffer from ethanol being fuel injected like cars ( although not sealed like cars) or electric.

In the meantime I have heard about aspen fuel which was originally made for loggers in Scandinavia to stop them getting cancer. It is much cleaner has no ethanol but a lot more expensive. Proponents say it keeps the carb clean and pristine , smells better, the engine runs better etc The reviews are primarily for garden engines.

Some boat owners, especially motor boats,use normal fuel with additives during the early part of the season  and switch to Aspen when the boat is starting to be laid up to remove the normal fuel from the engine.

I do not use the engine much so the cost is not too prohibitive so  I wanted to know if anyone has used Aspen in outboard engines and how they faired?

Thanking you all in advance
Andy B

[Graham W]

Andy,

There have been lots of recommendations on the forum over the years for Aspen 4, especially since unleaded E10 was introduced.  If you are only using your outboard for short journeys at the end of a sail, it's a no-brainer.  Compare the extra £5-10 cost of a litre or two of Aspen to having to get your carburettor de-clogged or even replaced altogether.  Not to mention the safety issues of having your outboard fail on you at the worst possible time.

For more frequent and longer journeys, the judgement may be a bit more finely balanced, particularly as the cost differential between Aspen and E10 has increased from 3 times more expensive per litre to an eye-watering 5 times.  You can always follow other advice (also on the forum) to mix in petrol additives to your E10, run your outboard dry at the end of each session and never leave petrol in the tank (or fuel pipes) for long periods and especially not over the winter.

If I was still running my old Mariner 6hp, I would be firmly in the first (short journey) camp and even if I was taking longer journeys, I would still probably de-risk myself by spending extra on the Aspen.  The smaller the engine, in all likelihood the smaller the diameter of its carburettor jets, so the more compelling the argument for Aspen.

Having outboards with EFI instead of carburettors seems to be a way forward but as far as I can see, fuel injection is so far only available on outboards from 9.9 hp upwards. 

[Nick Orchard]

Andy - you can still get E5 petrol at the 'Super' or 'Premium' pumps. More expensive than E10 of course, but nothing like the cost of Aspen, usually about the same as diesel. It's still got ethanol but only half as much, so only half as bad. I ran my Yamaha 9.9 on it when E10 was introduced and never had a problem. As you and Graham say, EFI is the best solution, now available from Mercury, Tohatsu and Suzuki at 9.9+ sizes (but not Yamaha yet). (By the way I think your new carburettor is a Tohatsu not a Toshiba - the small Mercury engines are re-badged Tohatsu's)

[garethrow]

Andy

I have only ever used Aspen type fuel in my Yamaha 6hp and enjoy a clean carb + reduced fumes. I am in the short journey category and get through around 10 litres a year. I have had no porbelm of dirt , failing seals etc after 4 seasons. There are 2 or 3 alternatives to Aspen which are essentially the same I'm told - all being alkalyite fuels. Husquavana supply their version and there is another similar brand name that I can't remember. I have used all 3 with no noticeable difference. Cost is about £20 to £22 for 5 litres. One big advantage is a shelf life of around 3 years plus, particularlyif unopened. You can also get 1 litre bottles  - one of which I carry as an emergency reserve to put in the engine top / integrated tank should my fuel line fail from the remote tank.

Regards

Gareth Rowlands
GRP BR20 Halen Y Mor

[AndyB]

Thanks all for you responses. I shall redo my search on the forum for the other posts.

Nick,
You are right I always mix the 2 up it is Tohatsu. E5 is just as bad as E10 just takes longer to break the rubber down. The additives don't do much in this area. Tohatsu stands out as the only one being able to start without an electric start so it says. Not that I can afford to buy one yet....

So since I use the engine for short journeys  and a new carb costs £260 I shall take your advice and try out Aspen/Husqvarna.

[Sea Simon]

I agree with most of the above.

As a retired professional Marine Engineer, this "green" fuel bollox is a subject about which I  have quite strong opinions, having been caused a great deal of wasted time, effort and expense over many years. Simply put it's  not fit for purpose, and under some circumstances can be hazardous to the end users...imho.

We used to think E5 was slightly dodgy cr@p, until they forced us to use E10, and most "premium" pumped fuels now have E5 (all do in my area).

Most said on here (probably several times!) over the years. Search Aspen or Ethanol.

Also lots on the Drascombe association site eg at
https://www.drascombe-association.org.uk/vbforum/showthread.php?4999-Tohatsu-engine-stalls-at-%91tickover%92&highlight=Aspen

Brands. It has been put to me...
Mercury, premium-think Audi.
Mariner, steady mid range-think VW.
TOHATSU, cost conscious-think Skoda....but all basically the same thing...you pays your money?

Diesel is rapidly heading the same, retrograde, way, as they adulterate that product too in the name of "eco", apparently with few thoughts for decreased reliability  and therefore, the safety of the end user.
I now have to use preemptive diesel fuel treatments too. £50 for 500ml.

I've  just got an EPROPULSION outboard for my "go-away" tender, having solved the issue of recharging the battery on the big boat.
Another £100 for a 12v charger, plus wiring, fuses etc....
This project primarily  because my little Honda 2.3 is doable with carefully managed fuel supplies, but it really doesn't seem to like being bounced about in a locker/lazerette then being expected to perform on the tender at destination port.

GW - you may now say "I told you so"...or something similar

[Graham W]

It definitely pays to shop around for Aspen 4 and competing alkylates, probably all made at the same refinery in Sweden.  My calculation of Aspen 4 being five times more expensive than E10 unleaded was based on a local price for 5 litres of £37.50.  However, looking around online shows a very wide range of prices of between £25 (some garden machinery companies) and £50 (Amazon) for the same product.  Best value seems to be Husqvarna Power 4 alkylate, especially if bought in bulk (25 litres from Oakleys for £100).  Gulf and Stihl also have their own versions.

[Sea Simon]

GW, you are right about shopping around for Aspen. Relative bargains can be had at garden machinery dealers, especially if buying a few "gallons".

I've been told "aviation fuel" is a good alternative,  but my local flying club (my only contact being a one-off lesson, years ago) are not keen on selling small volumes to casual punters.

Footnote.  Since my new EPropulsion arrived, the Honda 2.3 has performed faultlessly...I'm on the fresh fuel monthly, plus additives, regime atm.

I'm still too nervous, primarily from a security perspective, to use/leave the electric outboard on my "home tender". That £1000 battery with a plastic handle for security makes me twitchy. I've  engraved my postcode into it...carefully...
Any other suggestions?

[Graham W]

I'm still too nervous, primarily from a security perspective, to use/leave the electric outboard on my "home tender". That £1000 battery with a plastic handle for security makes me twitchy. I've  engraved my postcode into it...carefully...
Any other suggestions?

I nearly always take my eProp battery home, or at the very least padlock it away in the locker, leaving the rest of the motor locked to the transom.  Without a battery, the motor is pretty useless and therefore less likely to be stolen - so far.

[Sea Simon]

Trouble is, tenders, by definition,  get left unattended at destination...

My home tender has a fglass underseat secure locker, but too small for battery. Transom reasonably solid.
Lightweight inflatable go-away tender of course does not. As a "soft tail" it has no hard points at all...
Have to admit, I'd not thought enough about this issue.
Perhaps long cable lock to pontoon, when possible?

I do feel that as these things age (and so folk with drive legs need new batteries), and also become more popular,  the value of the batteries will become widely recognised...and very sought after...

I've engraved the battery case in several places, and the leg too.
I've a motorloc to secure the leg to the boat, and best bet seems a cycle lock to secure battery to leg? Perhaps by removing the battery from the leg, and a shortish cable lock battery-leg, you could also disable the boat?
Tenders regularly get "borrowed" hereabouts,especially in high season...

Insurers seem suspiciously silent on EXACT details of security arrangements required to maintain cover.