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"I'm still trying to figure out what's inefficient about 157 less friction producing , power robbing, moving parts? Enlighten us Derp.....please."
That is the reason why the older four strokes had less power. The lighter parts of the modern four-stroke have minimised those losses, resulting in more power (aka higher efficiency).
That is what is in this, and it makes 102 to the tire. weighs 280lbs.
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The only reason you are getting more power at every RPM is basically because its TWICE as much motor.
How is that a fair comparison?
While your thermodynamics argument may make sense to you, it's not the true story.
You've got things like port size, carb size, RPM, rate of flow, etc. in there too.
It's just too bad most of the MFG's turned their back on the 2-stroke....at least in the US.
Other flaws are your comparison of different displacement engines, and really engines designed basically in different decades.
If you compare updated DI 2 stroke technology to a modern FI 4 stroke of equal displacement the 2 stroke wins in every possible way.
The 2 stroke is cheaper to manufacturer, used less energy to manufacture, it's more reliable, it's lighter, it's quieter, it's very emissions friendly, and if tuning is designed to make hp just equivalent to the 4 stroke, the torque and breadth of the 2 stroke powerband far exceeds that of the 4 stroke. This has been proven in several applications already.
You have made the additional error of not recognizing that 2 strokes are peaky, in an attempt to keep up w/ engines 2x the displacement.
http://twostrokemotocross.com/2009/06/two-strokes-strike-back/
I see that you have your own definition of "Efficiency" in terms of the amount of fuel burnt. Most folks who ride a bike are going to only look at the fact that a 250 2stroke will beat a 250 4stroke to the first corner every time...that's the kind of real world efficiency that counts.
OEM's didn't take the fact that parts would be a big money maker when they decided to change completely over to turds.
sorry.
that was supposed to be funny or "bait" right? no?
please blow that smoke up someone elses ass.
carry on this is pretty good.
"Australian firm Orbital is testing a 200bhp, fully emissions-compliant 1000cc twin that’s lighter and more fuel efficient than any rival four-stroke. Aprilia craves an accessible performance middleweight, says it could easily render its seminal RS250 Euro-3 compliant and has twice already come close to releasing such a bike."
Pit Row
Nope. My definition of efficiency comes from thermodynamic cycles.
epa, polution control,remember?
but how i see it, a 2 stroke technology had the ability to correct this, but yamaha had that 400yzf,then the four strokers took into high gear from the other race teams.
side note, 500 2 stroke bikes disappeared because of low sales.
but now we have a 450 four stroke that in all practical purposes replaced the big bore 2 stroke .
if you ask me, the manufactures could of made the three class structure work again if it was 125 2stroke,250 2 stroke and 450 4stroke open class . and never make a 250 four .
and call the 450/open class the premier class.
Who actually believed that horse shit.
You don't HAVE to build a different type of motor to meet EPA requirements.
You simply HAVE to meet EPS requirements - and 2 stroke technology could easily comply and not only comply but exceed that of a 4 Skin.
Serious question...have you ridden both bikes? Based on your posts, the answer to that has to be "no".
funny.
a 450 is bascially the same as a 500 in those days. seems ok now?
also ,yea,450 is closer to 500 2stroke ergo than a 250 2 stroke, but it is a relaxed easier to ride big bore bike.
The separate issue from this is should the two strokes have been forced out of competition by an unfair displacement rule and fuel rule changes. I'd contend that the reason the Japanese wanted the AMA to switch to four strokes was to put up a road block to KTM and other small manufacturer's from competing in "their" sport - AMA racing. Do you think KTM wanted to fully commit to four stroke engine production in 2001? At the time they were a small manfacturer recently back from the brink of bankruptcy. The expense to re-tool and design the four strokes, seems to me, would have been a very significant and risky expenditure for them. They had no additional outlets for their engines to help justify the costs like the Japanese did. I know KTM did some racing of four strokes in motocross so maybe they, in a sense, helped start the change over, but I'd be more apt to believe they'd have preferred continuing to race two strokes. The Japanese probably hoped that KTM wouldn't pursue the four stroke and walk away from AMA motocross competition and hence limit them to being a niche market supplier with small sales volume.
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