Dynamic air cleaner and carburetor pressurization system for air cooled internal combustion engine

A blower for producing first and second high velocity air streams from a single air intake, the second high velocity air stream being substantially particle-free;

• the blower comprising:
• a centrifugal impeller having on a front side blades arrayed about a hub, the centrifugal impeller mounted within a fan housing for rotation to draw in air through an air intake located above the hub in fan housing and into the center of the impeller, and to blow the air radially outwardly into the fan housing to create a first high velocity air stream;
• an opening defined through the hub for communicating air from the front of the centrifugal impeller to a back side of the first impeller;
• a second impeller positioned for rotation on the back side of the centrifugal impeller, the second impeller creating a vacuum in the vicinity of the opening in the hub of the first impeller that draws air from the front side of the centrifugal impeller into the second impeller for creating a second high velocity air stream;
• and
• a screen extending radially outwardly from the hub's center and over the opening;
• the screen having a size and position whereby it does not substantially interfere with air flowing from the intake of the housing to the first impeller but permits some air to flow into the hub opening;
• whereby smaller particles tend to be carried with the air into the first impeller, away from the hub opening;
• and whereby larger particles that are not carried with the air deflect off the screen and into the first impeller;
• the screen and the hub opening thereby cooperating to produce a generally particle-free second air stream.