2-strokes illegal in 2007?

[gonzo]

The new generation two stroke Evinrude E-Tec engines are so quiet they had to add a safety feature to the starter switch. You can't crank them unless the engine is stopped. Owners were damaging the starter and flywheel because they couldn't hear their engine idle. We tested one of the E-Tec 250 and a Volvo XP side by side, and we could carry on a conversation between boats at 40 MPH.

[Mychael]

I'm guessing that the larger engines would have the physical space/size to allow the fitting of the latest technology to make a 2 stroke "clean".
I wonder though would the same be possible with the small (under 8hp) engines?
To use my motor again as an example, it's new (less then 6 months old) but is not really happy at idle and even running a 50:1 ratio I notice quite an oil slick in the fresh water flushing tank I have at home. So if I am contaminating the 200litre(44gal) drum with 60 second run ups, how much must I be putting into the sea running the engine for half an hour or more every time I go out to my boat?

Mychael

[Ike]

One of the first 4 stroke outboards sold in New Zealand was a Chrysler Hillman Imp motor (55HP) stood on its`s end.There were not many sold.The reason for adding lubricating oil to two stroke fuel is to lubricate the motor it does not burn but finishes up all over the place and even drips out the muffler

Sounds like the first car I ever owned, a Hillman Husky

[tom kane]

Auto Union turned out in the 60`s a rather snappy three cylinder two stroke car which went very well,although head winds and hills needed extra gear changes.They did leave a trail of smoke though.It seems there is not and idea that has not been tried somewhere in the World.

[Mykul]

From what I have learned from my searching wheather 2>4. there are some lakes in the USA that CARBORATED 2 strokes are illegal. DI 2 strokes have much better emisions ratings than there carborated counter parts.

[mydauphin]

I dont think so. The VTecs are two strokes and they meet all emissions standards.

[Mykul]

Yes that is what I meant. The new Evinrude E-tecs & Merc Optimax are direct injection. The difference is how the fuel is mixed with air. The fuel dosnt go through the crank case so right there you use less oil because the fuel cant wash the oil off the moving parts.

[safewalrus]

this rising it's head again? instead of small engines why not try a pair of oars? healthy stuff, trolls easily can be stopped instantly, only lubrication needed is a can of beer every now and then - only problem is it requires somehing people are not much good at these days, it's called WORK! But hell it's a damn more satisfying and it does you and the enviroment good! (cheap too surprisingly enough - shame about the dirty four letter word!)

[mydauphin]

Quickie story... I have two outboards a Nissan 4 stroke 5hp and 115hp 2 stroke Evinrude. The Evinrude is attached to a 21' center console, the 5 hp sometimes to a canoe or jon boat I have. The 2 stroke uses oil mix with gas, never had a problem with it. The 4 stroke in huge fine waiting to happen. Everytime I move engine unless I keep it perfectly vertical the crankcase oil spills in carb and piston. I have to pull plug and oil shoots out of it falling in water covering with a nice blue sheen. I then have to refill engine with close to a quart of new oil to get it running and get the hell out of there.

Anyway I had a two-stroke motor before and replace it because I thought 4 stroke would be cleaner. Not true, with this thing it is always a pain to store or it spills oil.

Just something to think about!

[marshmat]

Anyway I had a two-stroke motor before and replace it because I thought 4 stroke would be cleaner. Not true, with this thing it is always a pain to store or it spills oil

Good point. Not an issue for something that lives in a slip or on a trailer, but a cartopper or other light boat where you're taking the engine off a lot will cause problems with the oil on some 4-strokes.

Yes that is what I meant. The new Evinrude E-tecs & Merc Optimax are direct injection. The difference is how the fuel is mixed with air.

A conventional 2-stroke mixes air and oil/fuel, then sends that mixture into the crankcase, then sends it from there into the cylinders. As both the intake and exhaust ports have to be open simultaneously so that the fresh charge can displace the exhaust gases, some unburned fuel inevitably gets into the exhaust. Hence the terrible emissions rating of a carb'd 2-stroke; they do OK on many counts but they emit piles of unburned (and toxic) hydrocarbons.
A DI two-stroke brings only the air into the crankcase, and only the air goes from the crankcase to the cylinder. The fuel is injected straight into the cylinder AFTER the exhaust port is closed, so virtually all the fuel is burned. The control of the air/fuel ratio is much better and no raw fuel escapes. Hence why they're so much cleaner.
The actual mechanism of injection is different in each make. If I recall correctly, Optimax injectors blow a charge of high-pressure air through a metered quantity of fuel, forcing it into the cylinder. The old FICHT injectors used a metal ram to inject fuel at high pressure through a tiny nozzle. There are any number of variations. It's worth noting that the direct injector concept is very similar to the injectors of most diesels, which as we know can be designed to last darn near forever- or fall apart in months.