Abstract: An air filter assembly includes a housing having an interior surface that defines an interior volume, a filter element positioned within the interior volume and having a filter media, an air intake formed in the housing, a debris outlet formed in the housing, a filtered air outlet formed in the housing, and a plurality of ribs. The filter element is spaced from the interior surface so that a gap is formed between the filter element and the interior surface to allow air to flow between the filter element and the interior surface. The plurality of ribs extend into the interior volume of the housing so that air flowing from the air intake is directed into the gap and around the filter element to complete a cyclonic filtering pass before flowing along a second airflow pass through the filter element. The outlet passage is configured to direct filtered air into a third airflow pass in a direction opposite to the second airflow pass.

Abstract: An internal combustion engine includes an engine block, an air-fuel mixing device, and an air filter assembly. The air filter assembly includes a housing, a filter element, and a gap between the filter element and the housing. The housing includes a base and a cover which define an interior volume. The housing includes an outlet passage fluidly coupling a filtered air outlet to a final air outlet. The filter element divides the interior volume into a filtered volume and an unfiltered volume. The gap is configured to direct air in a first airflow pass before being filtered by the filter element. The filter element is configured to direct filtered air in a second airflow pass in a substantially opposite direction from the first airflow pass. The outlet passage is configured to direct filtered air into a third airflow pass in a substantially same direction as the first airflow pass.

Abstract: An internal combustion engine includes an engine block, an air-fuel mixing device, and an air filter assembly. The air filter assembly includes a housing, a filter element, and a gap between the filter element and the housing. The housing includes a base and a cover which define an interior volume. The housing includes an outlet passage fluidly coupling a filtered air outlet to a final air outlet. The filter element divides the interior volume into a filtered volume and an unfiltered volume. The gap is configured to direct air in a first airflow pass before being filtered by the filter element. The filter element is configured to direct filtered air in a second airflow pass in a substantially opposite direction from the first airflow pass. The outlet passage is configured to direct filtered air into a third airflow pass in a substantially same direction as the first airflow pass.

Abstract: An internal combustion engine includes an engine block including a cylinder, a horizontally oriented crankshaft, an air-fuel mixing device configured to provide an air-fuel mixture to the cylinder, and an air filter assembly configured to provide filtered air to the air-fuel mixing device. The air filter assembly includes a housing comprising a first housing end portion and a second housing end portion and defining an interior volume, a filter element positioned within the interior volume dividing the interior volume into a filtered volume and an unfiltered volume, a gap between the filter element and the housing configured to allow air to flow between the filter element and the housing, an air intake, and a filtered air outlet.

Abstract: An internal combustion engine includes an engine block including a cylinder, a horizontally oriented crankshaft, an air-fuel mixing device configured to provide an air-fuel mixture to the cylinder, and an air filter assembly configured to provide filtered air to the air-fuel mixing device. The air filter assembly includes a housing comprising a first housing end portion and a second housing end portion and defining an interior volume, a filter element positioned within the interior volume dividing the interior volume into a filtered volume and an unfiltered volume, a gap between the filter element and the housing configured to allow air to flow between the filter element and the housing, an air intake, and a filtered air outlet.