Swallow Yachts Association
Swallow Yachts Forum => Technical => Topic started by: michaeln on 10 Oct 2016, 19:26
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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.
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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!
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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.
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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
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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.
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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.
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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.
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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.
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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.
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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
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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.
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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!
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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
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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
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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?
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Good advice Peter to fill petrol on filling - I've just had my Tohatsu 6HP serviced by Keith Fairbrother (Chester) and he found corrosion in the carburetor caused by water in the petrol. The corrosion was so bad that Keith fitted a new carburetor. Ouch. Last summer the carburetor filled with jelly within months of servicing - same problem - water in the petrol. I use an external tank which Keith says are vulnerable to water ingress - he recommends emptying all petrol and wiping it out internally to make sure no water is left. For the amount of motoring I'll do I will just use the internal tank but be careful if I have to top it up when running and its hot...
I'm also giving Aspen petrol a trial, as recommended by Graham, which can be found at: http://www.aspenfuel.co.uk/products/environmental-fuels/aspen-alkylate-petrol/aspen-4-alkylate-petrol/ Not cheap at £20/5 litres and hassle to locate, until you cost lost time and fury when the outboard won't start.
Matthew
BR20 Gladys
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[quote I use an external tank which Keith says are vulnerable to water ingress -
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Matthew. Thanks for sharing your painful experiences .. new carb sounds pretty drastic.
I was very interested in your comment re external tanks vs internal. I've just had my Mercury 6 serviced too. (Same engine, my chap says the only difference is that if the Tohatsu needs warranty work the importers will always challenge it, whereas with the Merc they will authorise the work straight away to save the 'good' name of the Mercs!!).
I can't recall your set up on Gladys but most people I think keep their external tanks in one of the side lockers out of the way and in the dry. I do on my 23. As far as I can see the only way water could get in, unless of course it's already in the petrol, is through the breather release in the tank cap - if it's in a locker and the tank sealed down after use each time then I would have thought that was unlikely, whereas the breather on the internal tank is subject to rain and spray ingress..?
As I said in an earlier post I spoke with my mechanic about Aspen - basically he said don't waste your money, just make sure you use fresh fuel - just get smaller amounts of fresh fuel each time, a lot cheaper than buying special fuels - as I use quite a bit of fuel I think that is probably my best option.
He didn't think much of additives either, but said I could try 'quickare' which is a Mercury Quicksilver fuel additive, which I will try as they can't then dispute the warranty if it all goes belly up.
So all in all I'm still confused as to whats best ... I dare say this conversation will run and run .. (unlike some of our outboards..!)..
Cheers
Andy
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I was very interested in your comment re external tanks vs internal. ... As far as I can see the only way water could get in, unless of course it's already in the petrol, is through the breather release in the tank cap
So you take the boat out on a nice warm day and the wind drops and you motor back. While motoring the breather is open to allow air in to replace the petrol you use up. Warm marine air contains water vapour (order 10g/kg). You pack the boat away and close the breather. It's a cold night and water condenses from the air onto the insides of the tank and runs down into the petrol. Even without condensation the alcohol in the petrol is hygroscopic and can absorb water vapour from the air in the tank.
Not much water on each trip but for lazy people like me who simply keep topping up the petrol tank, then the water could collect in it. I assume that an exterior tank is likely to be more of a problem because there is more air space and it is rarely if ever emptied (at least mine isn't). One can imagine water collecting at the bottom of the tank only to go into suspension when you are out on a rough day.
I actually read my Tohatsu manual the other day (!RTFM - shock, horror!) and it mentions having a water excluding filter in the fuel line from the petrol tank. A Tohatsu Unikas UF-10K Outboard Fuel / Water Separator Filter costs about £70 bought from the USA on ebay. Force 4 has a different filter unit for £40 + cost of fittings to connect in fuel line and to fasten it so it and the fuel tank can still be removed to fill. I think I'll investigate!
Peter
p.s. the guy who services my outboard doesn't think additives are needed and thinks I'm worrying too much about fuel problems. However his main business is servicing RIBs and their outboards, and I can quite believe that outboards on RIBs don't have the problems which outboards on sailing boats experience!
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Sound words of wisdom as always Peter.. Yes. You are quite right of course and I see how that would introduce water into the tank..
A separation filter would I think be wise. After all diesel engines on yachts use one - glass ones so the collected water can be easily be seen and drawn off when necessary...
Maybe your servicing guy is right that we are worrying too much - The chap who does mine too doesn't seem bothered at all by fuel - as long as it's fresh. I know loads of other fishermen, sports motor boat owners, jet skiiers, sailors and all sorts who use outboards daily and none seem to fuss about this as much as I do - at least the bar empties when I start to mention it..!
And none of this answers the question of why my lawn mower - that I fill with last years ob fuel, never gets even an oil change just keeps on going - started second pull this year with fuel in it that I left in from last year....
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I know loads of other fishermen, sports motor boat owners, jet skiiers, sailors and all sorts who use outboards daily and none seem to fuss about this as much as I do - at least the bar empties when I start to mention it..!
Andy,
If they use their motors daily, then the fuel will always be fairly fresh. If, on the other hand, your small outboard sits idle for weeks on end, any fuel left in the pipes and carburettor will probably become stale. There's then the potential to cause the sort of fuel problems that have driven me up the wall with two different engines. Large engines (and lawn mowers) don't seem to suffer in the same way.
An economy solution to the problem is to use garage-bought petrol during the season but to run it dry just before the season's end. Then run some Aspen 4 through it on the last few days of use. It will still be in good condition the next season, allegedly. I'll let you know how I get on next spring, when I've been through the full cycle. I'm not worried about cost as I use so little fuel anyway.
The Tohatsu website says that the water/fuel filter is particularly recommended if you use fuel with ethanol in it, as the latter more readily attracts water. If I still have problems despite the Aspen, then water in the fuel from condensation will be the next thing to worry about....
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And none of this answers the question of why my lawn mower - that I fill with last years ob fuel, never gets even an oil change just keeps on going - started second pull this year with fuel in it that I left in from last year....
It's because mowing the lawn is much less pleasurable than sailing.
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I've now installed a Unikas UF-10K Fuel-water separator filter which is claimed to trap "over 99% of any water that may be present in the tank". It's advertised in the States as an accessory for Tohatsu (and other) outboards (the filter is distributed by Tohatsu America Corp.) but I couldn't find a UK source so bought it via ebay from 411-Marine who were advertising the filter assembly plus a replacement filter for $85. With shipping costs it was about £100.The filter offered by my Tohatsu dealer in the UK was about half that price but significantly more bulky and harder to accommodate than the Unikas version.
Whether this was worthwhile or a waste of money remains to be seen! I use a fuel additive which, if it works as claimed, will mean the filter collects no water... only time will tell! I'll report back at the end of the summer.
Peter
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Following warnings from a variety of sources, this forum included, I've just fitted a Yamaha filter/water separator unit for the 9.9 Yamaha on my BC26. It's rather larger than necessary as I didn't realise that Yamaha sell two versions, one for engines up to 70hp and another for engines up to 300hp, so my large version will allow me to fit a 300hp engine - should get me home a bit quicker! It has a paper filter to keep sludge etc out of the engine and any water in the fuel should separate out and settle at the bottom of the plastic bowl as it's heavier than the fuel. A red plastic ring will float on the water so it should be easy to see if there's any in there, in which case it can be drained off via the screw fitting on the bottom. The small version is about £70 and available from e.g. Bottom Line Marine. I understand that all petrol now has at least 5% of ethanol in it and is labelled 'E5' on the pump, but this may go up to 10% or 15% in future in order to meet emissions targets, so the problem of water in fuel is only going to get worse.
Nick
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Hi Nick, by coincidence I just discovered the Yamaha filter on Ebay this morning. I assume it goes in the fuel line to the motor and therefore can be fitted to any outboard, not just Yamaha. It's cheaper than the one I bought and available in the UK which is an advantage when it comes to replacement filters.
Peter
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Hi Peter
Yes there's nothing Yamaha specific about the filter and I'm sure it would be fine with any make of engine. Fuel goes in one side and comes out the other, hopefully cleaner and drier. Another advantage of buying the smaller filter is that I think it has the same 6mm pipe connections as Yamaha use for the fuel line on their small engines. The larger filter has 8mm or 10mm connectors, so I had to buy some 8mm pipe and 8mm-6mm in-line connectors (£3.99 on Amazon), so not a significant cost.
Nick
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Here we go (or not) again. After having two outboards last year clogged in carburettors with probably ethanol induced gunk and "varnish" I'm paranoid about fuel system cleanliness.
I have 9 year old external plastic tank and fuel line with bulb. The fuel line and fittings I shall replace with new on the principle I can't see what's inside. The tank itself looks clean through the filler cap - but is it? Has it got "varnish" contamination stuck to the inside? How can I tell? How can I remove it? Does it matter?
Matthew
Gladys BR20
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Mathew
My Yamaha 4 hp very rarely gets used but always starts. I add Sta-bil marine fuel 360 to the internal tank and after running the engine in the bucket I turn off the fuel and allow it to run dry the fuel available to it. Every two weeks I do this over the winter and after running dry it takes normally eleven pulls to get the fuel through again and start. After that 1st pull to start it again. So this works for me. I change my own impeller; fuel filter, engine oil, and marine quality grease the bits that need doing annually. The external tank is kept empty of fuel between uses along with the feed hose and priming bulb.
Peterc
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Having just collect my 9.9 Yamaha engine from its annual service yesterday I thought people might be interested in the thoughts of Chris Hoyle of Kingswear (Dartmouth). (Only took him 2 weeks this year, down from 3 weeks last year). (Mind you it cost an eye-watering amount - 40% more than a 10,000 mile service on my Tiguan at a VW main dealer!). Anyway, enough moaning, here's what he said when quizzed on the problems of water in fuel:
1. He recommends not buying cheap supermarket fuel. He reckons that after a while it turns from the pale green colour of new fuel to a brown colour, and it also loses its smell, so pay a few pence more for 'proper petrol'..
2. Don't use fuel more than 4 weeks old - put it in your car (no not the diesel one!) or lawnmower - how big is his lawn??
3. Don't switch the engine off to stop it, disconnect the fuel line while it's running and let it run dry.
He actually told me all this last year, but I have to confess that I've studiously ignored it all. I've used Sainsbury's fuel, I've never stopped it by disconnecting the fuel (turning the key is so much easier), and the can gets re-filled when it's empty. I've had a half full 12l tank sitting there all winter but it started pretty much first time before I took it off for the service, and that was after clearing the snow out of the cockpit! I asked Chris what state the carburettor was in when he serviced it and he said 'fine!'
I also looked at the colour of the fuel in the bowl of my filter/water separator today and it's still looking green and it smells very like petrol. I can also report that after running about 30-40 litres of fuel through the engine over the last year, the red ring that indicates the presence of water in the filter is still sitting firmly on the bottom.
I expect that I'll be now punished for ignoring all these wise words by the engine packing up next time I'm just about to park it in the marina - I shall report again in due course!
Nick
BC26 008 Luminos II
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It’s time to revive this topic. There’s an article in the Times this morning about the amount of bioethanol in standard UK garage petrol being doubled to 10% from next year. The idea is that although the net net effect on CO2 emissions from this move will be small, it will stand us in good stead once they’ve worked out an economic way of producing bioethanol from forestry waste, algae and baby foxes instead of from crops.
So if you’ve ever had any outboard carburettor problems from using E5 forecourt petrol, they’re likely to get even worse from next year with E10. You have been warned.....
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Very much agree with GW, below, on this.
The new EC10 petrol spec is all over the news today!
I've got no experience of this grade of fuel (perhaps our foreign readers may able to illuminate?) But I'm sure it's not good news for small 4 stroke outboards, nor for users of older petrol cars?
I'd stockpile more Aspen, but I've neither the money nor storage space since we "prepped" for the coming covid apocalypse ????
Is it a conspiracy!?!
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Due to soon take delivery of Coast 250 with 70hp outboard. Boat will be kept on pontoon so any engine failure will be very problematical. However this large outboard devours fuel, so Aspen is not an option. Went to Esso website to find following: "Esso super unleaded petrol (Synergy Supreme+ Unleaded 97) is ethanol free (except in Devon, Cornwall, the Teesside area and Scotland)" I'm no expert at all on engines and fuel, but is this Esso fuel an answer?
James Phillipps
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Well, this is a really interesting new issue. A first on this forum, I would think?
I ran a big dory for several years, with an older two stroke Mercury 60hp on it. You're right, I wouldn't want to feed it Aspen- ££££! Mine was carb fed. As that boat lived on a mooring, and we had (still have) no pumped petrol in Fowey, I fuelled mine by taking the big 25 ltr tanks to the garage. A pal with a big ski boat found it easier to haul the boat out, and take the whole thing to the garage, as he had an underfloor tanks of about 50 gallons!
Hopefully, yours will be fuel injected? Better for fuel consumption , emissions etc.
So, What does OEM say re E10 fuel?
If injected, my guess - as I have no experience- is that you should be ok if you try to avoid/minimise cheap and nasty fuel. Marina petrol is often not the best anyways?
The issue seems to be with this new crappy petrol in small carburated engines, as i can run our petrol car successfully on fuel that cannot be used in my small petrol outboards.
Similarly, but different. My garden machines run fine on reject petrol.
They are 2 stroke and so have more tolerant carb settings?
If a fuel injected outboard, i think you'll be ok.
Looking forward to learning more about this!
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Ironically, while they're busy stuffing bioethanol into supermarket petrol, there's been a rush on the bottled stuff by people who want to make their own hand sanitiser fluid.
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Will cars get gummed up while out of use during the virus hiatus?
Matthew
BR20 Gladys
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Will cars get gummed up while out of use during the virus hiatus?
Matthew
BR20 Gladysó
Lots of internet advice about, gues you've probably found that by now?
But may be best to go to oil majors, or in this case RAC or similar. It does seem to vary!
https://www.rac.co.uk/drive/advice/know-how/does-fuel-go-off-old-fuel-and-fuel-storage-questions-answered/
I think it perhaps depends on your car?
I'd more worried about older carburated cars, I think?
For example, my wife's fiat 500 will be ok with a can or two of fresh fuel, after layup. It regularly sits for 4 weeks or so for holidays. Not so confident about my colleagues DB 9!
Luckily, not a problem that I have, my suv is Diesel!
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There's nothing so useful as a spray can of Easy Start in a locker! Although an uncle of mine used to start his old diesel bread delivery van (you know, the ones in the 1960's with sliding doors) after a long lay off by dropping a burning rag into the air intake (after he'd removed the airfilter). It seemed to work every time.
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Update.
I've just cleaned the carb on my small Honda 2.3 (used on dinghy, and BRe when racing) for the first time this short season! This motor generally runs on supermarket fuel, as failure is an irritant, rather than a danger.
I'm using my ultrasonic cleaning bath now. Very effective, but obviously still need to strip the carb. The amount of crap disdlodged is amazing.
The new Honda 5 on the BRe still seems to be fine, generally run on Aspen fuel. Just as well, as is still under warranty and I don't want to pay dealer prices for carb cleaning.
More evidence that Aspen works?
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To me, the most important evidence was when I hauled out my Mariner 6HP from the shed last month, getting ready to sell it. It hadn’t seen any use at all for three years but with the small amount of Aspen 4 left in the internal tank started up almost first time and continued to burble away happily with no smoke and no smell. I was so impressed that I gave my purchaser a couple of litres with the admonition to use nothing else.
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I thought people might be interested in an update to my post of 3 years ago regarding using a fuel filter/water separator to combat the effects of ethanol in petrol.
I fitted my filter about 5 years ago and I've not touched it since. I've checked the water indicator from time to time but never seen it show any signs of having any water in (the red ring at the bottom of the bowl will float at the interface between the water and the lighter fuel). I thought it was about time I changed the filter element this year so before draining it I took a photo of the bowl and the red ring still on the bottom. As you can see there's no evidence of a single drop of water, so maybe it's not as bad as we feared. Over the 5 years of use I estimate that it's had about 250 litres of fuel through it, most of it from Sainsbury's. I've not taken a great deal of care to avoid leaving part-filled fuel cans on board - I don't have a petrol car or lawnmower so what do you do with half a tank of 3 month old fuel? The only measure that I have taken recently since unleaded went up to E10 is to use super unleaded which is still E5.
Having said that, I'm pondering changing the engine to a bigger 15HP unit, not for the extra power but because some manufacturers (Mercury/Tohatsu/Suzuki) are now using fuel injection instead of carburettors on smaller engines, but only down to 15HP. The other advantage is that they come with 12A alternators instead of the 6A that you get on the 9.9HP engines, and now that I have the luxury of a fridge I need to feed those batteries!
Happy motoring!
Nick