In a water-cooled outboard marine engine, a heat transfer portion is provided in an exit passage located between an outlet end of a cylinder water jacket and a cooling water outlet passage at a position upstream of the thermostat valve. The blade assembly is disposed within the housing and the guide directs cornstalks toward an input port on the housing. Each louver is attached by fasteners and each stanchion has the capability to be reversible without modification to the louvers or stanchions.