Astonishing two stroke outboard stats

NormanS said:
I don't understand why 2 stroke outboards are deemed to be so polluting, compared to things like chainsaws, of which there must be many more.
If you really want to get your teeth into a polluting waste, Dylan, let me point you towards a gas fractionating plant, not terribly far from my hometown. For days on end it has been flaring off vast quantities of gas, with a flame that can be seen for 60 miles. The noise of it can be heard for miles, and the amount of gas being burnt off would heat a city. That's real waste and pollution.
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Many of us have made similar comparisons on this and another thread, but he's well and truly got the bit between his teeth.
 
You know what its just Dylan to likes to talk .
He needs a cause but this cause is very tame
he needs to find something more substantial
that really will help save the planet
recycling is very good for-instance reusing all the old seagulls lying in sheds,the co2 has been released already from their manufacture many years ago
producing and transporting new outboards halfway round the globe releases new co2[China for-instance has masses of dirty coal powered power stations] and uses valuable resources and energy at this time when the planet is suffering from greenhouse gasses etc
 
Dylan, the comment about rainwater "wash-off" from urban areas is very telling. There are many millions of cars, almost all operating & parked on impervious surfaces. they leak & drip oil 24/7 & rainwater washes that into the drains, & into rivers & out to sea.

Now compare that to a few thousand O/B's, most of which are laid up in dry sheds or garages for 90% of their life. Cars must be contributing many times more oil waste to the seas & estuaries than outboards.
 
outboard420-420x0.jpg





Donald Stewart _ Polluter in Chief
http://www.odt.co.nz/your-town/wanaka/44961/seagulls-tackling-record-run

donald_stewart_readies_himself_for_a_325km_boat_tr_6662870064.JPG
 
I suspect that there is some truth in the assertion. But it's probably using extremes to draw pointless comparisons and conclusions.

2 strokes are notorious bad at using fuel. More than a little fuel does not get burned, it goes through the exhaust port. Nothing new here. The very latest 2-t designs use direct injection technology which gives big improvements.

"Perfect" combustion is when all of the fuel is burned with all of the air, called stoichiometric. The resulting byproducts of combustion are CO2 and water. Imperfect combustion creates CO, HC (unburned fuel) NOx (related to the speed and temperature of the combustion process) and PM, particulate matter (soot from diesel).

Most of the emissions get zapped by cats or filters so never make it out of the tail pipe. Diesels run very lean so there is by definition almost zero HC.

Modern day electrickery ensures that the fuel is burned in a gasoline engine; some also use leanburn technology. It wasn't that long ago, though, that a gasoline engines ran at 10:1, very rich, so leaving high HC tail pipe emissions. High powered engines also used "fuel cooling", that is, the engine and materials technology could not support the resulting 1000 deg C exhaust temperature. Reducing air/fuel ratio lowered the temperature.

Typical propoganda in support of some tree hugging interest.
 
dylanwinter said:
but there is a really good alternative to a two stroke outboard

it is a four stroke outboard.

If those stats are correct.....and I hope that some of the sharp minds on here will take a good look at the data and come back to us ... then continueing to use a two stroke when there is a perfectly good alternative would seem to be really rather irresponsible Dylan
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OK so I'm irresponsible but don't give a *hit! My rubbish Suzuki DF6 4/ is up for sale, replaced with 2nd hand 2/ Tohatsu. 4 HP more for same weight.
 
Niander said:
one hour with a ten hp equivalent to 25,000 car miles.....
That cannot be true...pure BS im suprised you believe it!
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a cursory glance at this proves its total BS, without going into the relative merits of the combustion process in 25,000 miles the average car would have at least 1 oil change say around 4 ltrs of waste oil and should have burnt at least 1 ltr (if it didn't its not working properly) - in I hour the 2 stroke would use say 50cc of very flammable degradable oil.
 
You've Just Reminded Me

To turn the kitchen into an Outboard workshop .... as my Yamaha 2~ 2hp is a tad-stiff to turn over .... so it's going to receive a jolly-good stripping & a mega-dose of ACF50 .... just about everywhere!

I can't do it in the shed cos I need light & power .... +! ..... I have heat & a kettle in the Kitchen .... :D

++! SWMBO is out! :D :D
 
Lakesailer thats a vintage Seagull 102 you have there
has a nice cover plate ..in very nice condition.
now that outboard will have been made just after the second world war and still going strong...fantastic mate!
 
dylanwinter said:
if it is true then it is amazing


http://www.kimointernational.org/Web...s/RESL102D.pdf

"Two-stroke engines used by many pleasure boats are a major source of hydrocarbon and
other toxic emissions in coastal areas. The high emissions from traditional two-stroke
engines are caused by the design of the motor. Twenty to thirty percent of the fuel and the
added oil that these two-strokes use are emitted unburned directly into the water. At low
speeds, up to 40 percent of the fuel entering a cylinder might escape unburned while at the
most efficient operating range eight percent of the fuel is expelled as exhaust. A one-hour
ride on a boat with a 10-horsepower traditional two-stroke engine emits the same amount of
hydrocarbon pollution as driving a modern automobile 40,000km (25,000 miles)."
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Dylan

The Swedes are notorious for over egging green statistics. I would not argue with banning 2-strokes on still inland waters (or Seagulls anywhere) but to ban new small 2-strokes on tidal waters as the EU has done is a nonsense.

The Swedish paper you quote does not say which 2 stroke – and which car they are comparing. Take the worst of the first and the best of the last and you might get the result they quote but that is not the consensus of most papers.

The Swedish paper goes on to argue that reducing 2-stroke use is fundamental to cleansing the North Sea. Now that really is mad. When did you last cross the shipping lanes on a calmish day? The whole of the North Sea lanes are covered by a layer of yellow/orange haze. Not even a fleet of Seagulls could achieve that. Shipping is the problem. The statistic the Daily Mail published of the 16 largest vessels putting out as much sulpher contamination in a year as the annual pollution produced by all the vehicles in the world may be as doubtful as the Swedish paper but you only have to look to see that there must be a significant problem.

So what extra impact does my little 4hp 2-stroke on the Orwell have compared to all those container vessels 5 miles down river. The answer is actually none because I was stupid enough to let it go with my last boat and buy a new 4hp 4-stroke. It is so much heavier that its dangerous to transfer it to the dinghy and I end up rowing all the time.
 
I surrender

PeterR said:
Dylan

The Swedes are notorious for over egging green statistics. I would not argue with banning 2-strokes on still inland waters (or Seagulls anywhere) but to ban new small 2-strokes on tidal waters as the EU has done is a nonsense.

The Swedish paper you quote does not say which 2 stroke – and which car they are comparing. Take the worst of the first and the best of the last and you might get the result they quote but that is not the consensus of most papers.

The Swedish paper goes on to argue that reducing 2-stroke use is fundamental to cleansing the North Sea. Now that really is mad. When did you last cross the shipping lanes on a calmish day? The whole of the North Sea lanes are covered by a layer of yellow/orange haze. Not even a fleet of Seagulls could achieve that. Shipping is the problem. The statistic the Daily Mail published of the 16 largest vessels putting out as much sulpher contamination in a year as the annual pollution produced by all the vehicles in the world may be as doubtful as the Swedish paper but you only have to look to see that there must be a significant problem.

So what extra impact does my little 4hp 2-stroke on the Orwell have compared to all those container vessels 5 miles down river. The answer is actually none because I was stupid enough to let it go with my last boat and buy a new 4hp 4-stroke. It is so much heavier that its dangerous to transfer it to the dinghy and I end up rowing all the time.
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I have given up
 
Any talk of Banning seagulls is ridiculous ...it could never be enforced for a start..isn't it enough the EU have banned new 2strokes?...even they knew not to ban 2strokes already in use....totally unenforceable and i think you'd be surprised the number of boaters still using them even just for backup...there would be a bit of an outcry, rebellion and refusal to comply...:)
...but im all for reasonable discussion but it must be reasonable any talk of seagulls polluting the vast sea is absolutely ridiculous!
 
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