Abstract: A power lawnmower having a body, a motor mounted to the body with a vertical drive shaft, a cover over the motor defining a power source chamber and a cutter blade below the body. Located on the drive shaft below the motor is a fan enclosed within a cylinder having openings therethrough. An opening in the cover admits air in to the motor chamber through an air filter. Two rows of ribs extending downwardly from the cover provide a filter cavity for receipt of the air filter in this opening. A second filter is positioned atop the motor and compressed between the motor and the cover. This air filter is retained by positioning ribs extending downwardly from the cover to the motor. An attachment mechanism mounting the blade to the drive shaft incorporates an attachment plate to which the blade is attached, a socket receiving the end of the drive shaft and two collars. A first collar is located within the socket and abuts against the end of the drive shaft.