Abstract: An outboard motor comprises an engine block having vertically-aligned first and second banks of cylinders that extend from each other in a V-shape, a vertically-extending central drain passage located below the first bank of cylinders and being configured to drain lubricant to an underlying sump, a vertically-extending crankshaft, and a central deflector located between the first and second banks of cylinders. The central deflector extends from the engine block towards the crankshaft and being configured to deflect lubricant away from the crankshaft to the central drain passage.

Abstract: A marine engine comprises a cylinder block that defines a cylinder bore; a piston that reciprocates in the cylinder bore under force of combustion in the marine engine; and a liner disposed in the cylinder bore between the piston and the cylinder block. The liner provides a running surface for the piston. The liner has a cylindrical liner body that is sized to fit snugly within the cylinder bore and a pair of diametrically opposing tabs axially extends from liner body into the cylinder bore. Methods of making a marine engine are also disclosed.

Abstract: An outboard marine engine comprises a crankcase; a crankshaft disposed in the crankcase and being rotatable about a crankshaft axis; a crankcase cover on the crankcase, the crankcase cover enclosing the crankshaft in the crankcase; and an air intake plenum that is integrally formed with the crankcase cover. The air intake plenum conveys intake air for combustion in the outboard marine engine.

Abstract: An outboard marine engine has an engine block; a crankcase on the engine block; a crankshaft disposed in the crankcase for rotation about a crankshaft axis; a cover on the crankcase; a bedplate disposed between the engine block and the cover, the bedplate having a plurality of bearings for supporting rotation of the crankshaft; and a cooling water jacket that extends parallel to the crankshaft axis along a radially outer portion of the plurality of bearings. The cooling water jacket carries cooling water for cooling the plurality of bearings and at least one oil drain-back area is located adjacent to the cooling water jacket. The at least one oil drain-back area drains oil from the crankcase.

Abstract: An outboard marine propulsion device comprises an internal combustion engine having a cylinder head and a cylinder block and an exhaust manifold that discharges exhaust gases from the engine towards a vertically elongated exhaust tube. The exhaust manifold has a plurality of inlet runners that receive the exhaust gases from the engine, and a vertically extending collecting passage that conveys the exhaust gases from the plurality of inlet runners upwardly to a bend that redirects the exhaust gases downwardly towards the exhaust tube. A cooling water jacket is on the exhaust manifold and conveys cooling water alongside the exhaust manifold. A catalyst housing is coupled to the exhaust manifold and a cooling water jacket is on the catalyst housing and carries cooling water alongside the catalyst housing. A catalyst is disposed in the catalyst housing.

Abstract: An outboard marine propulsion device comprises an internal combustion engine having a cylinder head and a cylinder block; and an exhaust manifold that discharges exhaust gases from the engine towards a vertically extending catalyst housing. The exhaust manifold has a plurality of horizontally extending inlet runners upwardly that receive the exhaust gases from the engine, and a vertically extending collecting passage that conveys the exhaust gases from the plurality of horizontally extending inlet runners to a bend that redirects the exhaust gases downwardly towards the catalyst housing.

Abstract: A support system for an outboard motor provides a restricted member that is attached to a bottom portion of the outboard motor and a restricting member that is attached to a support structure that is, in turn, attached to a transom of a marine vessel. The restricted member is prevented from moving in a starboard or port direction by a magnitude greater than a preselected magnitude that is defined by a gap between restricting and restricted surfaces that move into contact with each other when forces on the outboard motor cause a lower portion of the outboard motor to move by a magnitude greater than a predefined limit in either the port or starboard directions. Preselected gaps between restricting and restricted surfaces are sized to allow nominal vibration at low operating speeds of the outboard motor while restricting excessive lateral movement during operation at high speed.

Abstract: A four-cycle internal combustion engine is provided with a scavenge pump and a pressure pump that are both attached for rotation to a crank shaft of the engine. The inlets and outlets of the scavenge pump and pressure pump are located at positions within the structure of the internal combustion engine which inhibits the drainage of lubricant from a lubricant reservoir to the engine when the outboard motor is either tilted at an extreme angle from vertical or stored in a horizontal position. The scavenge pump and the pressure pump can be gerotor pumps and can either be located proximate each other at one side of the engine or displaced from each other on opposite sides of the engine.

Abstract: A cover for an outboard motor is provided to protect an operator from a flywheel. The cover is disposed under the cowl of the outboard motor. The cover is made of a generally rigid material, such as plastic, with first and second sheets being associated together to form conduits with openings extending therefrom. In one particular embodiment, one of the openings is shaped to receive an inlet of a compressor and this provides a positioning aid in attaching the cover to the engine. This device eliminates the need for flexible hoses and accomplishes two tasks with one component. It provides air conduits for the air passing through the cover and it provides a generally rigid means for locating the proper location of the cover.

Abstract: A lubrication system for an internal combustion engine directs a dedicated flow of oil to the cylinder bores of an engine. In addition, a more traditional oil circuit is provided to lubricate the components within the crankcase of the engine. A 2-way valve is used to alternate the flow of oil from an oil pump through the two alternative circuits according to a duty cycle that is selected as a function of a pre-selected engine parameter. The engine parameter, in a typical application, is shaft speed or rpm. By directing oil to the cylinder bores at a higher duty cycle when the engine speeds are low, the pistons are adequately lubricated when, otherwise, the low engine speed could cause difficulty in providing a proper flow of lubricant to the cylinder bores.

Abstract: An outboard marine drive having a midsection between the upper power head and the lower gear case and having a removable midsection cowl assembly including first and second cowl sections. The midsection housing includes an oil sump in one embodiment and further includes an exhaust passage partially encircled by cooling water and partially encircled by engine oil for muffling engine exhaust noise. The midsection housing also has an oil drain arrangement providing complete and clean oil draining while the outboard drive is mounted on a boat and in the water wherein the operator can change oil without leaving the confines of the boat and entering the water.

Abstract: A latch system for securing upper and lower cowl sections of an outboard motor. The latch system comprises a catch assembly located at one end of the cowl assembly, and a latch mechanism located at the other end of the assembly. The catch assembly includes a catch block mounted to one of the cowl sections, with a catch slot formed in the catch block. A roller member is mounted to the other of the cowl sections, for engaging the catch slot. The catch slot is formed so as to provide an end wall against which the roller is maintained when the cowl sections are secured together, with the material of the catch block engaging the roller member to prevent relative vertical movement between the cowl sections. A cam block is located at the same end of the cowl assembly as the latch mechanism, and is mounted to one of the cowl sections. A cam follower is mounted to the other of the cowl sections, and engages a cam surface formed on the cam block for facilitating movement of the roller member into the catch slot.