Outboard was fine, now won't start.

skyflyer

skyflyer

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2-stroke, running fine at home in dustbin of water after winter service and spruce up. It started first or second pull every time. Only think I changed after that was fitting a new plug. It was stored inside since then until yesterday

Today I tried to start it on the dinghy having filled from - wait for it - half empty plastic tank of premix that had been on my boat all winter and was probably made up 9 to 12 months ago.

The outboard wouldn't start. I checked spark at plug, and noticed plug was damp but oddly it didn't smell much like petrol. The stuff in the tank does have a much stronger petrol smell

It occurred to me there might be water in the fuel so I drained the carb bowl by undoing drain plug and allowed the liquid to run free for a bit.. I noticed when some drips went into the water, accidentally, that rather than spread out over the surface in a rainbow, there were cloudy white billows dispersing beneath the surface.

I then tried starting it again and it sprang to life immediately for about ten seconds then died

So the obvious thing is now to try fresh fuel. But out of curiosity I have previously heard of old fuel going off, (which I had trouble believing) not least because the stuff I tested it with at home is probably almost as old! Does two stroke 50-1 mix spread out in the water like raw petrol or does the oil mixed into it make it emulsify and disperse?

Anyone like to make a best guess? Water in fuel or some sort of degradation? Similar experiences anyone?

I have undone air vent and fuel tap is on, by the way!
 
skyflyer said:
2-stroke, running fine at home in dustbin of water after winter service and spruce up. It started first or second pull every time. Only think I changed after that was fitting a new plug. It was stored inside since then until yesterday

Today I tried to start it on the dinghy having filled from - wait for it - half empty plastic tank of premix that had been on my boat all winter and was probably made up 9 to 12 months ago.

The outboard wouldn't start. I checked spark at plug, and noticed plug was damp but oddly it didn't smell much like petrol. The stuff in the tank does have a much stronger petrol smell

It occurred to me there might be water in the fuel so I drained the carb bowl by undoing drain plug and allowed the liquid to run free for a bit.. I noticed when some drips went into the water, accidentally, that rather than spread out over the surface in a rainbow, there were cloudy white billows dispersing beneath the surface.

I then tried starting it again and it sprang to life immediately for about ten seconds then died

So the obvious thing is now to try fresh fuel. But out of curiosity I have previously heard of old fuel going off, (which I had trouble believing) not least because the stuff I tested it with at home is probably almost as old! Does two stroke 50-1 mix spread out in the water like raw petrol or does the oil mixed into it make it emulsify and disperse?

Anyone like to make a best guess? Water in fuel or some sort of degradation? Similar experiences anyone?

I have undone air vent and fuel tap is on, by the way!
Click to expand...

Non smelly drips that disperse is water/petrol emulsion. Petrol, oil and 2 stroke mix all spread out on top.

The thing is old OLD fuel never went off, its the old NEW fuel that will not store.
 
skyflyer said:
2-stroke, running fine at home in dustbin of water after winter service and spruce up. It started first or second pull every time. Only think I changed after that was fitting a new plug. It was stored inside since then until yesterday

Today I tried to start it on the dinghy having filled from - wait for it - half empty plastic tank of premix that had been on my boat all winter and was probably made up 9 to 12 months ago.

The outboard wouldn't start. I checked spark at plug, and noticed plug was damp but oddly it didn't smell much like petrol. The stuff in the tank does have a much stronger petrol smell

It occurred to me there might be water in the fuel so I drained the carb bowl by undoing drain plug and allowed the liquid to run free for a bit.. I noticed when some drips went into the water, accidentally, that rather than spread out over the surface in a rainbow, there were cloudy white billows dispersing beneath the surface.

I then tried starting it again and it sprang to life immediately for about ten seconds then died

So the obvious thing is now to try fresh fuel. But out of curiosity I have previously heard of old fuel going off, (which I had trouble believing) not least because the stuff I tested it with at home is probably almost as old! Does two stroke 50-1 mix spread out in the water like raw petrol or does the oil mixed into it make it emulsify and disperse?

Anyone like to make a best guess? Water in fuel or some sort of degradation? Similar experiences anyone?

I have undone air vent and fuel tap is on, by the way!
Click to expand...

UGH!

When one starts a Seagull one almost always gets a few drips of fuel released into the water. Never noticed anything other than a film spread across the surface of the water. God knows what was in your tank ... perhaps he peed in it!

If you are going to store fuel from one year to another do so in full, tightly capped metal cans. The aim being to reduce exposure to air to a minimum. prevent evaporation of lighter components and exclude light.

I do this very year but I filter it before use and also mix 50:50 with fresh.

i think that as ethanol has been added fuel is less likely to store well for long periods and this will get worse if/ when the ethanol content is increased further
 
You say its a 2 stroke and now has old fuel in it, that's probably fatal. Best thing you can do is buy a nice shiny 4 stroke. I could probably give you a few quid for the 2 stroke parts if that helps.

So plug out clean and in the oven for 20 minutes, carb off and strip, wash out with clean new petrol. Re-assemble and listen to the zing and she fires up first time.

Oh something about a very small filter in the fuel tap springs to mind on some of the small outboards, worth a check that it and the pipe are clean.

Pete
 
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WE only buy ethanol free outboard fuel, fortunately our marina only sells that kind anyway, with an inflated price natch. Our outboard is a 4 stroke but I was warned by all and sundry when I bought it never use gas from the gas station which is10% ethanol. I also add (probably more than needed) Startron fuel stabiliser to the gas tank contents since fuel can sit in there unused for some time between dinghy outings. Back when we had a 2hp Honda (4 stroke again) in the UK that would periodically go on strike due to gummy fuel. One time it was resolved by swapping the fuel with fresh, othr times needed a visit to the honda docs and an exchange of beer tokens. Dealer stripped the carb, having removed all sorts of bolt on stuff blocking access, then cleaned it with some kind of spray solvent and blew compressed air through all jets etc. I bought an aerosol can of carb cleaner to use in extremis myself but it frightened the motor int submission and it never failed to start after that.
 
My BIL (mechanic) told me just the other day when I was trying to start a 2ST generator to always drain the tank dry if putting it away for some time
 
A couple of years ago, I was doing the service on my 3.5 OB and was amazed when I removed the fuel cap and smelt the contents, and the best description I can give was that it smelled like white spirit. I drained the tank, and replaced with fresh and the engine started straight away
 
Swap it for a "nice" four stroke? You've got to be joking, heavy, expensive, need to be kept upright - UGH!

The engine tank was dry when stored - in fact it was new - It was a plastic fuel can that the old fuel was stored in. Being airtight and leakproof I assumed it would neither allow water in nor solvent out!

In a dark locker so light not an issue

As noted in my original post the engine was running fine having stripped and cleaned carb, fuel tank, pipes etc. They don't suddenly gum up with three pulls if the starter handle!

I'll report back once I get some new petrol. Marina has run out right now so trip to a garage seems inevitable

:-)
 
The addition of the premix oil to petrol causes the petrol to go off. It has a very distinctive smell once it goes off. You can't store premixed petrol/oil for any length of time. Once petrol/oil mix goes off, in small quantities it turns to a jelly which causes real problems in the carburettor as it's hard to remove.

As for ethanol, this is causing problems in old vehicles, particularly 2 stroke bikes. Ethanol contains up to 35% oxygen, so when concentrations of ethanol reach 10%, it starts having an effect as more oxygen can cause some bikes to run lean, with potential results such as seizures and even holed pistons. It also causes some rubbers to degrade, such as needlevalve seals and hoses.

more info here: http://www.mag-uk.org/en/campaignsdetail/a6973

When a fuel is advertised as 'cleaner for your engine' or some such thing, then it has a high concentration of ethanol, which acts as a solvent, cleaning abrasive deposits form your engine. It may benefit you if you run a new car on this fuel since new, but for any older cars it can cause problems such as accelerated wear. The contradiction is that the fuel supply is so variable you have no idea what you are putting in the tank.
 
I had a similar problem at the beginning of last year. Engine wouldn't start. I opened the drain pug on the bottom of the carb bowl and like you no rainbow film on the water. It appeared to be water coming out. The engine had been stored the whole year on the transom and I thought I may not have closed the breather correctly (unlikely) but it's all I could think of at the time. I remember running the engine dry at the end of the previous season so I think it's more like just to have been condensation in the bowl or tank allowing water to form. After draining the carb bowl. I drained what little there was in the tank filled with clean fuel and off it went. After suffering several times from a gunged up float chamber I'm now under the impression "running dry is not such a great idea as there is always some fuel left and it will evaporate quicker than a full bowl leaving behind some crud. Best solution is to run regularly or even just open the fuel cock and give a couple of pulls on the starter cord. I used mine this weekend for the first time this year with last years fuel and it started and ran perfectly.
 
Spyro said:
I had a similar problem at the beginning of last year. Engine wouldn't start. I opened the drain pug on the bottom of the carb bowl and like you no rainbow film on the water. It appeared to be water coming out. The engine had been stored the whole year on the transom and I thought I may not have closed the breather correctly (unlikely) but it's all I could think of at the time. I remember running the engine dry at the end of the previous season so I think it's more like just to have been condensation in the bowl or tank allowing water to form. After draining the carb bowl. I drained what little there was in the tank filled with clean fuel and off it went. After suffering several times from a gunged up float chamber I'm now under the impression "running dry is not such a great idea as there is always some fuel left and it will evaporate quicker than a full bowl leaving behind some crud. Best solution is to run regularly or even just open the fuel cock and give a couple of pulls on the starter cord. I used mine this weekend for the first time this year with last years fuel and it started and ran perfectly.
Click to expand...

Two or 4 stroke?
 
Got petroil in my tank from the year dot - no problems BUT did have major probs, which my grandson sussed when he found a slight leak of air into the fuel supply line. - - disturbed by the gear change linkage - (Yamaha 5- 2 str)
 
These days I always disconnect the fuel line to run the carb dry ( takes ages) after use on our 9.9hp 4 stroke Mercury, then re-connect the fuel line ready for next time if the engine is to remain on the RIB in the davits. If the motor is to be lifted off for pushpit bracket stowage the tank remains in the RIB with fuel line coiled . Wen we had a little 2hp Honda the advice was to drain the carb via it's drain screw but it was not easily accessible but was very easily dropped in the attempt, so I turned the fuel tap off to run it dry, also took ages.

Edited to add. Not sure if running a 2 stroke dry might cause a lube problem?
 
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Robin said:
These days I always disconnect the fuel line to run the carb dry ( takes ages) after use on our 9.9hp 4 stroke Mercury, then re-connect the fuel line ready for next time if the engine is to remain on the RIB in the davits. If the motor is to be lifted off for pushpit bracket stowage the tank remains in the RIB with fuel line coiled . Wen we had a little 2hp Honda the advice was to drain the carb via it's drain screw but it was not easily accessible but was very easily dropped in the attempt, so I turned the fuel tap off to run it dry, also took ages.

Edited to add. Not sure if running a 2 stroke dry might cause a lube problem?
Click to expand...

No it doesn't. Not at idle speed anyway because it is then well oiled. It'll die due to a weak mixture before it has totally runs dry anyway. Not advisable though on large multicab engines, I understand, because the design of the fuel system can lead to some cylinders running dry while others are still getting fuel .
 
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