BOMBARDIER 1996 Ski-doo MX Z440 Handbook page 157

Air entering the bell of the carburetor has a speed of VI and pressure of P1. As the air is forced into
the smaller diameter of the venturi, speed increases (V2) but pressure drops (P2).
Passages in the carburetor connect the venturi to a reservoir of fuel (float bowl). The float bowl is
vented to the atmosphere (P1 ). PI is greater than P2 so fuel is pushed from the bowl to the venturi
via the jets and passages. Varying the size of jets varies the amount of fuel the engine receives.
Engine speed is controlled by varying the amount of air/fuel mixture that the engine receives.
Liquid gasoline does not burn, so for the engine to run efficiently, the fuel must be broken down
into small droplets, and mixed with the oxygen molecules in the incoming air. This is referred to as
atomization. The shape of the venturi an-d-the shape and location of the jets and fuel delivery
passages will determine how well the fuel and air are mixed.
A01C4AS
1. Float bowl
2. Needle valve
3. Float
4. Fuel inlet
4
Section ENGINE PREPARATION
04
– 2
3
04-55