Motorcycle Carburetor

A necessary component of a motorcycle engine. Some people didn't realize that a motorcycle has a carburetor, but it does. Like an automobile, they need a carburetor.

Motorcycle Carburetors are easy to understand once you have read up on how they work. Here we will give you a brief description on what exactly a motorcycle carburetor does.

Basically what a carburetor does is regulate engine speed. It does this by metering the amount of air and fuels required, to sustain combustion per the impute of the throttle servo. If the engine is in low speed idle, you would have a small amount of air and fuel entering the engine. This would in effect lower the chemical energy entering the combustion chamber thus lessen the engine power and subsequently lower the RPM's (Revolutions per minute). As you open the throttle (speed up) the carb will allow more air and fuel into the combustion chamber increasing the speed and rpm's.

The first principle you need to understand is atmospheric pressure. Atmospheric pressure is the pressure exerted by the atmosphere, not merely downwards, but in every direction. It amounts to about 14.7lbs on each square inch (PSI). By being able to manipulate the pressure in the engine and carburetor, you can change the pressure in the air and fuel.

Atmospheric pressure forces high pressure to low pressure. When there is low pressure in the carburetor, high pressure that is formed outside of the engine and carburetor force their way into the carburetor and engine until the pressure is regulated. The air moving through the carburetor will pick up fuel and mix together using the Venturi Effect.

The Venturi effect is what allows the carb to pull fuel form the fuel tank to mix with the air. This rule states that in a converging funnel, the entering fluids velocity increases as it passes through a reduction in the funnels throat diameter. This increase in fluid velocity decreases the localized pressure at the venturi throat to below atmospheric pressure. This low pressure region is exactly where fuel enters the carburetor throat.