Abstract: An internal combustion engine includes an engine block including a cylinder and a muffler assembly configured to receive exhaust gases from the cylinder. The muffler assembly includes a housing defining an interior volume and including an exhaust inlet and an exhaust outlet, and a baffle assembly positioned within the interior volume. The baffle assembly includes a plurality of chambers in fluid communication with each other. The plurality of chambers are in fluid communication with the exhaust inlet and the exhaust outlet so that the plurality of chambers are configured to cause exhaust gases to be directed through the muffler assembly from the exhaust inlet to the exhaust outlet through four passes in the baffle assembly before exiting through the exhaust outlet.

Abstract: An internal combustion engine includes an engine block including a cylinder and a muffler assembly configured to receive exhaust gases from the cylinder. The muffler assembly includes a housing defining an interior volume and including an exhaust inlet and an exhaust outlet, and a baffle assembly positioned within the interior volume. The baffle assembly includes a plurality of chambers in fluid communication with each other. The plurality of chambers are in fluid communication with the exhaust inlet and the exhaust outlet so that the plurality of chambers are configured to cause exhaust gases to be directed through the muffler assembly from the exhaust inlet to the exhaust outlet through four passes in the baffle assembly before exiting through the exhaust outlet.

Abstract: An engine assembly includes a crankcase, shaft, blower housing, and cooling fan. The shaft is rotatably coupled to the crankcase and defines a rotational axis. The blower housing includes an internal space. The cooling fan is disposed within the internal space, includes a plate defining an upper surface, and is positioned to rotate with the shaft about the rotational axis. The cooling fan includes a band having an inner band radius and an outer band radius. The cooling fan includes a plurality of reversed fins extending between the band and the upper surface and between a root adjacent to the rotational axis and a tip adjacent to the outer band radius, each fin offset at an angle measured in a counterclockwise direction from a plane passing through the rotational axis and the tip to a plane passing through the root and the tip when viewed from above the cooling fan.

Abstract: An engine assembly includes a crankcase, a shaft, a housing, and a cooling fan. The shaft is coupled to the crankcase and defines a rotational axis. The housing has a sidewall that defines an internal space. The cooling fan is disposed at least partially within the internal space and is coupled to the shaft. The cooling fan includes a plate defining an upper surface and a lower surface. The plate is positioned to rotate with the shaft about the rotational axis. The cooling fan also includes a band that has an inner band radius and an outer band radius. The cooling fan also includes a plurality of reversed fins coupled to the band and extending from the upper surface of the plate, further radially outward from the rotational axis than the band.

Abstract: A mower blade includes two symmetrical body portions disposed on either side of an axis of rotation, wherein each body portion includes a straight leading edge having a first sharpened edge formed along at least a portion of the leading edge, and a curved trailing edge having a second sharpened edge formed along at least a portion of the trailing edge, so that each body portion tapers to a rounded end.

Abstract: An engine assembly includes a crankcase, shaft, blower housing, and cooling fan. The shaft is rotatably coupled to the crankcase and defines a rotational axis. The blower housing includes an internal space. The cooling fan is disposed within the internal space, includes a plate defining an upper surface, and is positioned to rotate with the shaft about the rotational axis. The cooling fan includes a band having an inner band radius and an outer band radius. The cooling fan includes a plurality of reversed fins extending between the band and the upper surface and between a root adjacent to the rotational axis and a tip adjacent to the outer band radius, each fin offset at an angle measured in a counterclockwise direction from a plane passing through the rotational axis and the tip to a plane passing through the root and the tip when viewed from above the cooling fan.

Abstract: An engine assembly includes a crankcase, a shaft, a housing, and a cooling fan. The shaft is coupled to the crankcase and defines a rotational axis. The housing has a sidewall that defines an internal space. The cooling fan is disposed at least partially within the internal space and is coupled to the shaft. The cooling fan includes a plate defining an upper surface and a lower surface. The plate is positioned to rotate with the shaft about the rotational axis. The cooling fan also includes a band that has an inner band radius and an outer band radius. The cooling fan also includes a plurality of reversed fins coupled to the band and extending from the upper surface of the plate, further radially outward from the rotational axis than the band.

Abstract: A mower blade includes two symmetrical body portions disposed on either side of an axis of rotation, wherein each body portion includes a straight leading edge having a first sharpened edge formed along at least a portion of the leading edge, and a curved trailing edge having a second sharpened edge formed along at least a portion of the trailing edge, so that each body portion tapers to a rounded end.

Abstract: A mower blade includes a body including an axis of rotation about which the blade is configured to rotate, a first body portion extending in a first direction from the axis of rotation, and a second body portion extending in a second opposite direction from the axis of rotation, wherein the second body portion is asymmetrically shaped with respect to the first body portion such that the center of mass of the blade lies on the axis of rotation.