Fuel is then fed through tiny passages called "jets," which control how much gas flows into the combustion chamber-most carbs feature two jets, with the main jet controlling the fuel mixture at mid to high RPMs and the pilot jet controlling from idle to the middle of the rev range. While carburetors are elementary in function, tuning them properly is a long and arduous job that only veteran mechanics have perfected.
"Once you have a two-stroke 95 percent of the way there, that last 5 percent is really what's difficult to get down," says Joe Adragna, an amateur motocross racer who rode two-strokes throughout his childhood.
While a carburetor allows you to adjust the air-fuel ratio, it's more of a set-it-and-forget-it type of device. Fuel injection (or throttle-body injection in the case of KTM's two-strokes) is continuously variable. The process is now controlled automatically via an onboard engine management system that ensures a near-perfect air-fuel ratio all of the time. With more usable power and higher fuel efficiency, these engines feel much closer to a four-stroke when twisting the throttle open.
"We saw the benefits on the four-stroke side when we made the switch from carb to EFI more than 14 years ago," says Bretterebner. "Some of these benefits apply even more on a two-stroke engine, which is more sensitive in terms of air-fuel ratio."
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Denne historien er fra March - April 2023-utgaven av Popular Mechanics US.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
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Whether We Live in a Simulation - scientist Melvin Vopson, PhD, studies this exact thing- the possibility that the universe might indeed be a digital facsimile. And he claims to have evidence.
In the 1999 film the Matrix, Neo discovers A truth to end all truths-the universe is a simulation. While this premise provides fantastic sci-fi fodder, the idea isn't quite as relegated to the fiction section as one might expect. . In fact, University of Portsmouth scientist Melvin Vopson, PhD, studies this exact thing- the possibility that the universe might indeed be a digital facsimile. And he claims to have evidence.
The Ancient Language of Easter Island - Today, humans inhabit- or have, at the very least, explored- pretty much every corner of the planet. But that immense proliferation of Homo sapiens across the globe was a slow process.
With the first humans leaving Africa between 60,000 and 120,000 years ago, the species slowly spread across the Earth over many millennia. And one of the last places these ancient humans made their way to was the southeastern Pacific island of Rapa Nui, known more broadly as Easter Island.Located 2,360 miles off the coast of Chile, Rapa Nui is one of the most isolated places in the world. Its native people, who are also named the Rapa Nui, first arrived on the island's shores between A.D. 1150 and 1280, and lived in isolation until the arrival of Dutch navigator Jacob Roggeveen in 1722.
Underwater UFOs - A retired U.S. Navy admiral believes that the government should look to the oceans to help solve a mystery in the skies.
A retired U.S. Navy admiral believes that the government should look to the oceans to help solve a mystery in the skies. Rear Admiral Timothy Gallaudet, former Oceanographer of the U.S. Navy, recently published a paper arguing that unidentified anomalous phenomena (UAP, more commonly referred to as UFO) and unidentified submersible objects (USO) are linked, and should be studied further.
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If you've ever done any kind of long-distance travel, or just woken up feeling under-rested thanks to daylight saving time, you know how important your circadian clock is. Like many things in your body, your circadian rhythm is more complicated than it might seem on the surface. Rather than being entirely brain-based, it's actually controlled by a collection of several circadian clocks (central and peripheral) that all work together to keep your gears turning like a well-oiled machine.
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With people moving around so much these days, it's perfectly natural to wonder how an editor can just come along and stick like a barnacle to the hull of Popular Mechanics, lasting for 35 years.
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