Running a 2-stroke outboard dry before storing ?

I've absolutely no knowledge of such engines, Vic, but wouldn't they have a pumped lubrication system? Or do they depend on plain old petroil?

AFAIK even with oil metering systems the oil is mixed with the gasoline and then fed to the carbs in more or less the usual way.
 
Crikey .... over the space of a few years we've gone from WD40 being a good lubricant to being a lubricant to being a poor lubricant to being the opposite of a lubricant. :)

Richard

Its never been a good lubricant. Some decades ago there was an article in PBO comparing WD40 with other products. As a lubricant WD40 came out poorly if not actually the worst of the products tested.

By Dr David White IIRC.
 
AFAIK even with oil metering systems the oil is mixed with the gasoline and then fed to the carbs in more or less the usual way.

As I wrote before, Vic, I've no idea what oil system big 2-stroke outboards might have used. Pumped lubrication in 2-stroke motorcycles dates back at least to the 60s. The more sophisticated versions, notably Suzuki's, had a direct oil feed to the bottom end via the main bearings, rather than simply dumping oil into the carbs. Oil fed to the carbs was more common, although I don't know of any version in which the oil was actively mixed with the fuel, except to the extent this would naturally happen as the oil, fuel and air rushed through the crankcase.
 
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As I wrote before, Vic, I've no idea what oil system big 2-stroke outboards might have used. Pumped lubrication in 2-stroke motorcycles dates back at least to the 60s. The more sophisticated versions, notably Suzuki's, had a direct oil feed to the bottom end via the main bearings, rather than simply dumping oil into the carbs. Oil fed to the carbs was more common, although I don't know of any version in which the oil was actively mixed with the fuel, except to the extent this would naturally happen as the oil, fuel and air rushed through the crankcase.

I thought motor cycles just mixed the oil with the petrol in the tank. I seem to remember garage forecourts had an oil dispensing pump for measuring out the right amount. I must admit I have not noticed them recently but then I cannot remember when i last saw anyone with a motor cycle in a filling station.
 
I thought motor cycles just mixed the oil with the petrol in the tank. I seem to remember garage forecourts had an oil dispensing pump for measuring out the right amount. I must admit I have not noticed them recently but then I cannot remember when i last saw anyone with a motor cycle in a filling station.

Petroil/pre-mix became steadily rarer from about 1970, although it continued in a dwindling number of cheap 2-strokes (mainly from the Eastern Bloc). By the Seventies pretty well all Japanese stinkwheels had separate oil tanks. Race machines mainly stuck with pre-mix. The garage dispensing pumps died out decades ago. Of course very few motorcycles are 2-strokes these days.

Our digressions would represent thread drift, were it not for the fact that motorcycles routinely ran their carbs dry: whenever the main fuel supply ran out and the rider had to switch to reserve. This never did any harm even to pre-mix engines, although it could certainly bother the rider's underwear if he happened to be overtaking with a lorry coming the other way at the time...
 
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Perhaps I should have been clearer; when laying up the engine for the winter I take out the plug, spray in WD40

- WD40 being the 40th grade of Water Dispersant the tried -

Pull the engine over a few times

then using an oil can inject a few dollops ( sorry to be technical, say 50ml ) of 2-stroke oil

Turn the engine over a few times again

Store engine in a warmish dry garage.

Keep an eye on the vertical gear selector shaft, this can seize up; oil poured to dribble down it can avoid heaps of trouble.

Ditto the leg shaft join, separate it while it's still easy.

Apart from cuddling the engine in its own electric blanket every night ( which I probably would do if it was a Merlin ) I reckon this seems to do the trick.
 
My understanding of the reason we spray WD40 or similar into an engine that is being laid up is that it has little to do with providing lubrication, it is all to do with preventing corrosion. Any combustion process produces water and if during the laying up process you only run the engine long enough to drain the carb you are likely to be leaving the engine full of the stuff! For this reason the final run of the year should be a decent one to get the crankcases properly up to temperature. Incidentally, I've never bothered spraying the inside of any of my two-stroke engines with anything, there's enough oil coating everything inside and all you risk doing is washing that off.

I'm surprised nobody has mentioned fuel yet. I always run my outboard on Super unleaded because it contains less (in some cases none) ethanol where regular unleaded contains up to 10%. Ethanol is nasty stuff, especially in engines that are not run often or are being laid up.
 
Adding extra oil possibly risks fouling the plug at the start of next season.
Personally if I know an small engine is going to be idle for a month or more, I drain the carb.
I drain the carb at the first hint of a cough or sneeze mid season too, it's quite common to catch a few drops of water.
I normally turn the fuel off well short of the slipway so the carb is more empty than full.

I'm not having any problems with standard unleaded in small engines.
The alternative view is that the ethanol actually helps, it will dissolve/intermix (there is a proper word but it escapes me at this point) small amounts of water and get it out of the carb and through the motor.
I suspect there is some truth in that, sometimes....

Also I believe in using a decent 2T oil, preferably synthetic, but I'm less fussy for my outboard which gets through a fair amount of fuel in a year and is probably going to corrode to bits before any serious wear happens. But for little engines like the Chinese strimmer, I reckon synth oil might help shall we say 'value engineered' bearing parts last a bit better?
 
If you can get your 2 stroke chinese strimmer engine to start in the first place!!
Adding extra oil possibly risks fouling the plug at the start of next season.
Personally if I know an small engine is going to be idle for a month or more, I drain the carb.
I drain the carb at the first hint of a cough or sneeze mid season too, it's quite common to catch a few drops of water.
I normally turn the fuel off well short of the slipway so the carb is more empty than full.

I'm not having any problems with standard unleaded in small engines.
The alternative view is that the ethanol actually helps, it will dissolve/intermix (there is a proper word but it escapes me at this point) small amounts of water and get it out of the carb and through the motor.
I suspect there is some truth in that, sometimes....

Also I believe in using a decent 2T oil, preferably synthetic, but I'm less fussy for my outboard which gets through a fair amount of fuel in a year and is probably going to corrode to bits before any serious wear happens. But for little engines like the Chinese strimmer, I reckon synth oil might help shall we say 'value engineered' bearing parts last a bit better?
 
Is the word your looking for"Hydroscopic"?
Adding extra oil possibly risks fouling the plug at the start of next season.
Personally if I know an small engine is going to be idle for a month or more, I drain the carb.
I drain the carb at the first hint of a cough or sneeze mid season too, it's quite common to catch a few drops of water.
I normally turn the fuel off well short of the slipway so the carb is more empty than full.

I'm not having any problems with standard unleaded in small engines.
The alternative view is that the ethanol actually helps, it will dissolve/intermix (there is a proper word but it escapes me at this point) small amounts of water and get it out of the carb and through the motor.
I suspect there is some truth in that, sometimes....

Also I believe in using a decent 2T oil, preferably synthetic, but I'm less fussy for my outboard which gets through a fair amount of fuel in a year and is probably going to corrode to bits before any serious wear happens. But for little engines like the Chinese strimmer, I reckon synth oil might help shall we say 'value engineered' bearing parts last a bit better?
 
Nope .... it's probably "emulsify". :)

Richard
No, it's the opposite of that. The ethanol supposedly acts as a co-solvent and dissolve the water in the fuel. I suspect the flip side of this is if it's already got saturated and is bringing water into the carb.
AIUI, people used to put alcohols, usually methanol, into petrol for this purpose?

My personal experience is that cooking unleaded from local garages isn't causing any more gumming problems than unleaded from the olde days.
I do have a nasty Chinese generator that won't start, but that has only just been un-earthed from the back of a shed where it's been for 2 years, so I would expect to have to clean the carb, same as I would have last century.

But go-faster deluxe unleaded isn't going to break the bank, so if it's convenient, why not use it?
 
Apparently not but I think the word you are thinking of is hygroscopic

Who cares, it allows the fuel to carry the water rather than remain separated and float on top of it.... I believe that's why they don't use ethanol in Avgas.
 
. I believe that's why they don't use ethanol in Avgas.

Who cares ?

Does the composition of Avgas or whether it float,s or not, have any relevance as to whether, or not, to run a small outboard dry before storing
 
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