Niche Industries Yamaha Big Bear 350 Performance Carburetor ~ MSRP $479.24 USD. Save up to 75% at Partdiscounter.com. Click on the picture to see more.
What is a carburetor and what does it do?
A carburetor controls the proportion of fuel to air going into an engine. It accomplishes this by regulating the airflow to the engine and adding the appropriate amount of fuel to the air. It's an important mechanism that helps your engine run smoothly by ensuring that the optimal ratio of fuel/air enters the engine. To reach this optimal ratio, the carburetor uses a vacuum. But how does a carburetor actually work? To better understand the basic functions, let's examine the different components that make up a carburetor.
Air flows to the engine through the carburetor; and inside the carburetor is a chamber where a vacuum is created. The throttle regulates how much air is allowed into the engine. The more open the throttle, the faster the air flows, and the stronger the vacuum in the chamber, giving more fuel to the engine. Moreover, inside the chamber, is a jet that is connected to the float bowl that feeds fuel to the engine. The float bowl acts as a small reserve of fuel to accommodate the carburetor's fluctuating fuel demands. Attached to the float bowl is the float and float valve, which regulates the flow of fuel into the fuel bowl. In the picture above, you can see the throttle valve inside of the carburetor and the float bowl at the bottom. On the other hand, most of the other parts mentioned in this post are not visible as they are contained inside of the carburetor.
To ensure that the optimal ratio of fuel to air is entering the engine, the carburetor uses different jets.The pilot jet regulates the fuel/air mixture when the engine is in idle, while the main jet regulates the fuel/air mixture when the throttle is open. To further fine-tune the fuel/air mixture according to the changing needs of the vehicle, the jet needle (which sits in the needle jet seat) adjusts the amount of fuel as you open and close the throttle by moving in and out to obstruct the flow of fuel. This means that when the engine is idling, the jet needle restricts and obstructs the flow of fuel while at full throttle the needle is not restricting the flow. Lastly, a choke is present to help provide the engine with a rich fuel mixture during the start up process. Together, these components work to provide the optimal fuel/air ratio for your engine.
Does your ATV or bike have a carburetor? Have you worked on it before? Let us know in the comments.
Want to see more about the Yahama Big Bear 350 Performance Carburetor? Check out our video below: