 Two show carburetors are so common in the refined nowadays that you might think that there's no way it can get any better without having to get some electronics into the mix. But smart carb has proven differently. Let's understand how this next generation carburetor works, how to adjust it and what makes this mechanical carburetor so simple yet so innovative. Stay tuned. The concept of a jetless single circuit carburetor is not a new one. This development started in the late 60s by William Redd Edmundston, a renowned American inventor. Unfortunately, Redd passed away in 2008, but Corridis, founder and CTO of Smart Carb Fuel Systems knew how valuable Redd's research was after having worked together for several years and wanted to pick up where Redd left off. Corriden bought the rights to Redd's research and after some R&D, Smart Carb introduced to the market the first single circuit, jetless, internal-evented with air-density self-compensation mechanical carburetor. That's a lot of features at the same time. But before we get into it, let's do a quick recap on how a traditional carburetor works. To enrich the mixture on startup, we pull the choke, which provides additional fuel to make it easier for the engine to start when it's cold. Once the engine starts, the choke closes and the idle circuit keeps the engine running. This circuit provides a small but steady amount of fuel whenever the engine is running on idle and a little over idle, through the pilot jet. When you twist more than around one-eighth of throttle, the main circuit steps in. Initially, the amount of fuel is determined by the space between the needle and the jet needle, and near full throttle, the main jet determines the amount of fuel going to the engine. A carb works like a charm when the jetting is spot on, but its biggest achilles heel has always been the inability to compensate for different air densities. If you usually ride at sea level and decide to ride at a higher altitude, where there's less air going through the carb, the mixture will become too rich for the same amount of fuel, and all these jets have to be retuned for the new air density. And not to even mention the fuel spillage of a carb. Hard and raw folks will know the struggle. But smart carb claims have solved all these problems and eliminated jetting once and for all. Let's take a look. At first glance, the smart carb 2 looks like a traditional machine carburetor without all the typical hoses. If we take a closer look at the Venturi, we note that it's not like the typical round Venturi in a traditional carb. Smart carb claims that this patented variable shape is responsible for providing a crisp bottom and response like in small bore carbs, but also a high mid to top end power delivery as in big bore carburetors. A smart carb is similar to a traditional carb, but essentially way simpler. You only have a choke, a float pole, a slide, a metering rod replacing the needle, and a fuel nozzle instead of the main jet. Something else. It almost sounds like a joke, but smart carb is that simple. Let's see how it works. On idle, the engine sucks fuel through the fuel nozzle, as opposed to the idle jet on a traditional carb. The position of the rod determines how much fuel the engine gets on idle. Once you start twisting the throttle, the slide and the metering rod lift. The increased low pressure point created by the airflow going around the metering rod sucks fuel from the float pole, and as the slide lifts, the variable cross section of the metering rod with the fuel nozzle is what determines the amount of fuel that gets mixed with the air according to the throttle input. The biggest breakthrough of this carb lies on how the fuel behaves when it goes through the metering rod. The metering rod has a flat like surface as opposed to the needle shape of a traditional carb. The shape of the metering rod helps the air create a sprinkler effect of the fuel, which provides an increased atomization of the fuel particles in the air. What does this mean? It essentially makes the fuel droplets in the air smaller, which are a lot easier to burn. This not only allows for a better combustion on the cylinder, increasing the power up to 10%, but also reduces emissions up to 50%. And being a jetless single-circuit carb, it will be up to the shape of the metering rod to determine the different engine behaviors. But luckily, you don't have to worry about any of that, as it all comes pre-tuned for you out of the box. And what about the elevation and temperature self-compensation? In essence, it means that the smart carb is able to compensate for different air densities. The smart carb has an intake scoop on the air filter side that is directly connected to the float pole. If you're riding on top of a mountain or in the African desert, the lower density of the air will apply less pressure on the fuel on the float pole, which will prevent too much fuel from getting sucked into the engine, avoiding a mixture too rich. In the other hand, if you're riding at sea level or during really cold weather, where the air density is higher, the air incoming from the scoop will apply more pressure onto the fuel on the float pole, making it easier for the fuel nozzle to suck more fuel into the engine, preventing the mixture from becoming too lean. So no matter if you're using the bottom end or riding flat out, the fuel on the float pole will always be pressurized accordingly by the incoming air from that scoop. In addition to this super clever venting system, which eliminates the need to have all the hoses you have on a traditional carb, the smart carb has no fuel spillage. On the venting circuit, the air can easily flow to the float pole, but there's a check valve in the middle made of two spheres. The bottom one is made of steel, and the top one is made of a special hollow plastic which floats in fuel. If the bike is leaning too much, the plastic sphere will float and block the fuel passage. If the bike is completely upside down, the metal spheres will push the plastic spheres, blocking any fuel passage. This internal venting system, combined with the increased atomization of the metering rod, allows you to increase your fuel mileage up to 30%. That's a lot more fuel in a tank or money in your wallet. But die-hard fuel injection fans might say, two strokes with carbs will be a thing of the past and will become useless when there's electronics involved. Smart carb has that covered as well. Not only can smart carb have a throttle position sensor included to match current oil injection systems on Betas or 3D ignition mapping on Japanese bikes, but their proprietary linear magnetic design on the slide is simpler and more reliable than TPS sensors found on traditional carbs, which have a moving mechanism. Pretty nifty, isn't it? However, the home tuners might wonder how they can tune their smart carb if they need to. After all, there's only one fuel circuit with a metering rod and no jets to change. On the smart carb, you can tune the bottom end response of the engine without any tools by changing the idle speed and the height of the metering rod. When you completely twist a throttle, the slide reaches the top of the carb. If you then press down the top adjuster, it engages with the metering rod. Then, if you turn the top adjuster clockwise, the metering rod goes up, allowing more fuel flow and making the mixture richer. If you turn it counterclockwise, the metering rod goes down, blocking more fuel flow, which makes the mixture leaner. And to help with tuning, the top handle works with clickers, the same way as in suspensions, so it becomes a lot easier to keep track of your changes. And what if you want to change the mid to top end response of the engine? For that, you have to open the carb stop cap and remove the slide to change the metering rod. But considering the clever adjustment system on the slide, you really don't have much to go wrong with when replacing the metering rod. The smart carb combines simplicity and innovation with significant improvement figures, making it the next generation carburetor and perhaps even delaying the need for fuel injection. Only time will tell. I'll also be doing some performance and fuel mileage tests, so keep an eye on the next episodes. Hope you liked it, thank you for watching and if you have any questions, leave them in the comments below.