Abstract: Mounting port, provided adjacent to a cooling water passageway, has a hole opening from the passageway for mounting an anode metal in the passageway. Lid member, which closes the outer end of the hole, has a head portion formed at its outer end and an externally threaded portion engageable with an internally threaded portion of the hole with a sealing member sandwiched therebetween. The lid member having the anode metal fixed thereto is inserted in and attached to the port with the threaded portions engaging with each other with a sealing tape sandwiched therebetween. Space is defined between an outer end portion of the port and an outer end portion of the lid member between the head portion and the externally threaded portion so that part of the sealing member protruding from between the threaded portions can be received in the space.

Abstract: In a structure for mounting a sacrificial electrode in a cooling water passageway provided in a cylinder block of a water-cooled engine for an outboard engine unit, the cooling water passageway is defined by a groove portion provided in the cylinder block and a lid member closing an opening of the groove portion, a gasket member is provided between the groove portion and the lid member, and a screw fixedly fastens the sacrificial electrode to a bottom wall of the cooling water passageway. The gasket member has an extension portion opposed to a surface of the head of the screw located remote from the bottom wall of the cooling water passageway.

Abstract: Mounting port, provided adjacent to a cooling water passageway, has a hole opening from the passageway for mounting an anode metal in the passageway. Lid member, which closes the outer end of the hole, has a head portion formed at its outer end and an externally threaded portion engageable with an internally threaded portion of the hole with a sealing member sandwiched therebetween. The lid member having the anode metal fixed thereto is inserted in and attached to the port with the threaded portions engaging with each other with a sealing tape sandwiched therebetween. Space is defined between an outer end portion of the port and an outer end portion of the lid member between the head portion and the externally threaded portion so that part of the sealing member protruding from between the threaded portions can be received in the space.

Abstract: In a structure for mounting a sacrificial electrode in a cooling water passageway provided in a cylinder block of a water-cooled engine for an outboard engine unit, the cooling water passageway is defined by a groove portion provided in the cylinder block and a lid member closing an opening of the groove portion, a gasket member is provided between the groove portion and the lid member, and a screw fixedly fastens the sacrificial electrode to a bottom wall of the cooling water passageway. The gasket member has an extension portion opposed to a surface of the head of the screw located remote from the bottom wall of the cooling water passageway.

Abstract: A four-cycle engine for an outboard motor includes an upwardly extending breather chamber which communicates with a projecting portion provided at a lower part of a crankcase and with an induction system via a PCV passage for returning a blow-by gas to intake manifolds. With this arrangement, it becomes possible to remove oil components from the blow-by gas within the PCV passage and hence to return the substantially oil-free blow-by gas to the intake manifolds.