Running a 2-stroke dry after use

I've run my outboard dry every time I put it away, as it may be a week or it may be a month, six months in winter, before I come back. It's what I was taught to do and I don't seem to have done any damage over the 15 years I had the engine - it didn't take any longer to start the day before it was stolen than it did when it was new.
 
Dan: whatever your preferred practice regarding fuel gumming, Mr Bane is just touting common myths.

So long as a pre-mix two-stroke is actually running, it's getting fuel and oil. This still applies as the engine is "running roughly" (usually not roughly at all: the revs simply rise briefly as the mixture weakens just before the engine stops). As someone else posted, the actually degree of mixture weakening is quite small: there's still plenty of oil going through.

You'll be aware that oil, unlike petrol, is rather reluctant to evaporate. If you've ever stripped a healthy two-stroke, you'll know that its internals surfaces are invariably coated with a beautifully clean veneer of oil. This doesn't instantly vaporise from the engine's working surfaces as soon as the mixture weakens. Two-stroke oils are engineered to be especially tenacious in this respect, and far, far beyond the needs of a humble tender donk.
 
I'm grateful to you, MacD, because now I feel I needn't go hunting for an out of date Mariner manual.

It's unfortunate that the contributor's article in the January 2017 PBO raised an unexplained and possibly unsubstantiated issue.

I think I'll run the engine dry as (I believe) it has always been, by former owners.
 
Agreed on the last few posts - it's a bit telling and bit weird that this has stretched to 3 pages.

Gentlemen, relax your sphincters; I've worked with two-strokes for thirty years. Just run the damn thing dry so it conks out and unless you're stashing it away for five years - it'll start up just fine next time you need it.
If you really feel the need to empty it - invert it, to empty the float bowl - but don't stress about that; you've got pre-mixed so there's oil in there and all is good in terms of carburettor internal surface corrosion issues as the fuel will evaporate off leaving a thin coating of oil as a preserving layer against the aluminium.

And, relax...

The best thing you can do for a two-stroke is buy good quality oil to do your pre-mix with. No Tesco stuff or Halfrauds.
And remember; a slightly smokey two-stroke (too generous with the pre-mix) is a happy two-stroke - though you might get some dagger-looks from the Extinction Rebellion lot on the shore. But don't worry about them; they're probably waiting for daddy to come round the corner in his Princess 40' to pick them up for a day of whale watching or some cr*p so they can post on Instasham.

Yes, it's Monday - and I'm in a bad mood but surely - enough - on how to wind down a bl**dy two-stroke engine.
 
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I think that was good news. :)

Nothing, I suppose, can answer why the chap wrote in to PBO and effectively advised the reader not to do what apparently we all do.

Is Quicksilver a premium o/b 2-stroke oil brand? When I brought a turboflame lighter at F4, they sold me a can of Swan gas to refill it, and I figured that was premium stuff. It wasn't premium enough...the turboflame never worked after I refilled it. I don't expect the outboard is so picky, but I definitely don't want second-rate oil.

Can anybody sum up when I'll need carb-cleaner? Helpfully, I mean. Every 2-stroke thread seems to mention carb-cleaner but I don't know when or why the carb would get dirty.
 
quicksilver is fine.
Carb cleaner is useful if the stale petrol leaves a sticky mess.
It may also remove little droplets of water from inside jets.
IMHO the main thing is to be able to take off the float bowl to ensure it's free of water or crud.
A squirt of carb cleaner is optional. Just removing the bowl and losing the water has got quite a few engines going for me.
Draining via the drain screw is 'second best' but worth a try.
Also, always carry a spare plug, plug spanner, shear pin and any tools needed to change that.
 
dancrane said:
I think

Can anybody sum up when I'll need carb-cleaner? Helpfully, I mean. Every 2-stroke thread seems to mention carb-cleaner but I don't know when or why the carb would get dirty.
Click to expand...

If you don't know what carb cleaner is or what it does then the best advice I can give you is to avoid it.
It is not to be used lightly.
 
lw395 said:
quicksilver is fine...always carry a spare plug, plug spanner, shear pin and any tools needed to change that.
Click to expand...

Thanks for all of that.

My Mariner has the shear-proof hub (I think). I have no idea what that means, except it doesn't have a shear pin.
 
I don't have my own outboard but I've used a lot of two stroke garden tools. The carb is different as it's just a simple membrane but the ethanol in the petrol is what gums up after lack of use in the winter. You can either run it dry, or as a special treat, run it on Stihls (expensive) Motomix as this is non ethanol high octane fuel with decent two stroke oil in it and safe to overwinter in the engine.

A litre of that in the tank for the last run of the season is cheaper than stripping the carb if you wanted to play safe or nuture a new engine.

https://www.stihl.co.uk/STIHL-Products/Fuel-Oils-and-Canisters/MotoMix/21098-1633/MotoMix.aspx
 
I don't believe ethanol is to blame.
Small carbs have always been prone to gumming up, since long before they put ethanol in petrol.
I think modern carbs are more vulnerable as they have very small jets, where old engines just ran rich at small throttle openings.
 
From the Esso site -

Esso super unleaded petrol (Synergy Supreme+ Unleaded 97) is ethanol free (except in Devon, Cornwall, the Teesside area and Scotland). We would therefore advise anyone who has concerns about the presence of ethanol in petrol to use Synergy Supreme+ – providing they do not fill up in Devon or Cornwall, the Teesside area or Scotland.
 
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