Pollution issues

[lnewqban]

Originally Posted by firstlog

....... I don't understand why the ktm 200 is 3 times more polluting than the honda 250. They both have 38mm carbs, the honda is an mx bike. I tend to think something else is going on here.........

"Two-stroke engines produce more pollution from:
-- The combustion of the oil in the gas. The oil makes all two-stroke engines smoky to some extent, and a badly worn two-stroke engine can emit more oily smoke.
-- Each time a new mix of air/fuel is loaded into the combustion chamber, part of it leaks out through the exhaust port."

http://www.deepscience.com/articles/engines.html

[anotherguy]

^^^^^^
Quoted from the the same article. Quite misleading. Don't pick through an article to suit your point. Use your own words. And that blue shit is difficult to read.

Most of what is written on advantages and disadvantages of 2 strokes Vs 4 strokes is not actually correct.

[GearHeadGrrrl]

Sure, that smoke looks nasty, but it ain't the really nasty stuff like particulate matter, etc.. And keep in mind that two strokes aren't obsolete, they can meet all the current emissions standards. For example, the 2 stroke diesel EMD locomotive engines are still being built and it looks like they may have an easier time meeting the upcoming tighter standards than the 4 strokes.

[FloridaSteve]

Sorry, late to this conversation but I have to jump in. I did not read every single post so take this as a stand alone to the original comment and a few responses I perused quickly. Two stoke biases are cocooned in myopic and willful ignorance and/or not looking at the total picture. These aren't your grand daddy's piston port oil splattering 2 stokes. We're talking about insanely efficient, often orbital or direct injected machines with engineered oils that are burned at about a tenth the percentages of even 15 years ago.

A KTM 200 is an amazingly clean and efficient 2 stroke power creating device in relation to a similarly performing 4-stroke machine (an in fact similar power per pound is essentially NOT possible for a 4 stroke without some pricy exotica) . That "similar" performing 4 stroke will use FAR more exotic and expensive metals with very short service intervals necessitating their rather frequent replacement. Ever been to a titanium mining facility? I have. Trust me, environmentally speaking, It's like earth raping.

Now, I realize that little puffs of smoke are psychologically more disturbing to people but it's simply not "just" what you can see that represents pollution. Last time I checked, "For off road use only" 4 stroke motorcycles usually have whatever catalyst device they "might" have been delivered with removed. AND the Increased weight of that "somewhat" comparably performing (yeah, right) machine also means a lot more fuel used. And don't forget, the fuel going through that engine is in reality only a portion of the total pollution "footprint of the machine over it's life cycle (see titanium mining comment above).

Look at the total "footprint" (carbon and otherwise) of similar machines over the course of their entire "normal" operating lifecycle and you will get a VERY different picture of how dirty or clean they are. And by that standard a modern, lightweight, efficient recreational 2 stroke is at a minimum on par and usually far FAR ahead of the comparable 4 stroke bike. By that view a Prius is actually a fairly filthy vehicle (go look at a nickle mine and what those impacts do to the environment and explain to me how "clean" they are). And don't even get me started on the orbital injected hyper efficient marine outboards that the marine marketing departments just can't seem to get rid of despite decades of trying. In that world the 2-strokes are cleaner, more efficient, and far better performing by any measure and for some reason people just keep buying them. Go figure.

If it makes you "feel" better, get one of the newer off road electrics. They are actually getting quite impressive for closed course joy riding. Just don't go researching where they get all those rare earths and elements to build the batteries and components. It might upset you.

[lnewqban]

Originally Posted by anotherguy

^^^^^^
Quoted from the the same article. Quite misleading. Don't pick through an article to suit your point. Use your own words. And that blue shit is difficult to read.

Most of what is written on advantages and disadvantages of 2 strokes Vs 4 strokes is not actually correct.

Don't read it then; anyhow, it seems that you are not willing to learn anything that may change your pre-concepts (right or wrong).

I don't tell anyone how to post, so please don't tell me how, unless you are a moderator of this site.

[anotherguy]

Wouldn't quoting the article tend to indicate I read it? You'll do well around here.

[FloridaSteve]

When I get some time I'll address that article and provide a few modern technologically comparable examples in response to this"deep science" blather regarding the most " technologically advanced" generation of engine being superior.. for the moment I'm calling it a night.

[lnewqban]

Originally Posted by anotherguy

Wouldn't quoting the article tend to indicate I read it? You'll do well around here.

If, showing such nice manners, you have done well, who wouldn't?

I have change the font's color of the unfortunate quote as per your suggestion.

Learning is my thing, not hostility.
Sorry, I just didn't expect such response to my first post in this site.

Still true, IMHO:

-- The combustion of the oil in the gas.

Modern 2S', with inlet and exhaust valves, direct fuel injection, ash free lubricants and pumped lubrication get close to 4S' regarding cleanness.

However, the whole amount of lubricant, although smaller than years ago, is exhausted.

-- ......., part of (fresh mix) leaks out through the exhaust port.

The power valve, can broad the curve of the engine flatter, but still some raw fuel escapes for any regime less than peak efficiency.

All this is achieved sacrificing the simplicity, lightness, cost and reliability of the original two-stroke engines.

I believe that nobody can accurately assess which engine is cleaner, since the many factors involved make it a moving target.

A huge 2S engine used in a ship rotating at steady speed (for which it has been designed) may be much cleaner that a little 4S engine used in a motorcycle rotating all over the range of rpm's and loads.

Evaluating the negative environmental impact of each type is equally difficult.
For sure, either 2S or 4S motorcycles, being the 3% of the registered vehicles in USA, cannot do more damage than the other 97%.

[ssregal39]

<> Btw. the Aspen gas is completly ethanol free and can be stored in years! I'am using it now for three years without any problems.<>

Man you folks in Europe are lucky not having to put up with the garbage fuel we have forced upon us here in the states. Stuff is terrible! That is all. and oh yeah 2 Smokes Rule!!!

[nsu max]

Sorry all, but this is how I feel and I'm sorry if I piss anybody off. After fortyfive years of watching/listening everybody tell us whats best for us and by "everybody" government and manufactures alike it's like this, I like my four strokes but you can't beat a nice light tourqie open class 2 stoke for tight trails, hell for two track and fire roads for that matter! The so called noise is music and the exhaust is prefume. end of story. One last thing if anybody has figured out how to get the spouse to dab a little castor oil or Klotz behind the ear please tell me after more than 30 years my wife still says no.

[anotherguy]

Buy one of these (not cheap 'bout $70/oz.) pour some out. Thin the bean oil w/VP C12 and pour into Joy bottle. Keep us posted on how it works.

[chollo9]