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%.