Abstract: A control system for an internal combustion engine, the control system receiving an input signal from an engine speed sensor, receiving an input signal from an engine knock sensor, advancing the spark timing of the internal combustion engine until a knock signal is received from the knock sensor, and, in response to receipt of a knock signal from the knock sensor, retarding the spark timing of the internal combustion engine until a knock signal is no longer received from the knock sensor and thereafter maintaining a substantially constant spark timing until the signal received from the engine speed sensor indicates a change in engine speed.

Abstract: The outboard motor includes an engine driving a propeller. The engine cover includes an upper dome-like cover sealingly connected to a lower pan-like cover. A combustion air opening through the upper portion of said upper cover has a partition inside the opening requiring entering air to travel upwardly into a chamber between a baffle between the inside of the upper cover and the cover. The baffle includes a portion cooperating with the cover to define a downwardly directed duct leading air towards said lower cover clear of the engine. The engine draws combustion air from the region of the lower pan to a higher elevation at the front of the cover while entrained water is deposited in the lower cover a pump discharges the water.

Abstract: A marine propulsion device comprising a mounting assembly adapted to be mounted on a boat and including a tilt tube extending along a generally horizontal tilt axis, a propulsion unit mounted on said mounting means for pivotal movement relative thereto about said tilt axis and about a generally vertical steering axis, said propulsion unit including a propeller shaft adapted to rotatably support a propeller, an elongated member slideably housed within said tilt tube for axial movement relative thereto, an extendible and contractible hydraulic assembly having a first end adapted to be connected to the boat, and a second end connected to said propulsion unit for causing pivotal movement of said propulsion unit about said steering axis, a valve including a first member fixedly connected to said second and end of said hydraulic assembly, and a second member reciprocally movable relative to said first member, and a link member having a first portion pivotally connected to said elongated member, a second portion piv

Abstract: Disclosed herein is a marine propulsion device comprising a lower unit including a gearcase, a driveshaft having an end extending into the gearcase, a pinion mounted on the end of the driveshaft, a propeller shaft bearing housing located within the gearcase having a forward end adjacent the pinion, a propeller shaft rotatably mounted in the propeller shaft bearing housing and having a rear end portion and a portion forwardly of the rear end portion, a propeller mounted on the rear end of the propeller shaft, a bevel gear adjacent the forward end of the propeller shaft bearing housing and engaging the pinion, the bevel gear including an annular forwardly facing thrust transferring surface, and an annular thrust transferring element mounted on the propeller shaft bearing housing and engageable with the annular forwardly facing thrust transferring surface so as to transfer thrust forwardly from the bevel gear through the thrust transferring element and to the propeller shaft bearing housing.

Abstract: A marine propulsion device comprising a propulsion unit adapted to be mounted on the transom of a boat for pivotal movement relative to the transom about a generally vertical steering axis, and about a generally horizontal tilt axis, the propulsion unit including a rotatably mounted propeller, an engine drivingly connected to the propeller, and a wall at least partially defining a cooling water jacket and having therein an opening communicating with the water jacket, and a fluid cooler extending through the opening and including a portion extending internally of the water jacket and having therein a fluid passage adapted to communicate with a source of fluid to be cooled in the fluid cooler.

Abstract: A marine propulsion device comprising a propulsion unit adapted to be mounted on the transom of a boat for pivotal movement relative to the transom about a steering axis, the propulsion unit including a rotatably mounted propeller, and an engine drivingly connected to the propeller and including a water jacket, a water pump connected to the water jacket for forcing cooling water through the water jacket to cool the engine, a fluid pump driven by the engine, a conduit communicating between the water jacket and the atmosphere, and a fluid cooler communicating with the conduit to receive cooling water from the water jacket and communicating with the fluid pump for cooling the fluid pumped thereby.

Abstract: Disclosed herein is a power steering system for a marine propulsion device having a propulsion unit movable around a generally vertical steering axis, the power steering system comprising a tilt tube for affording tilting movement of the propulsion unit around a tilt axis substantially transverse to the steering axis, a steering ram within the tilt tube for bi-directional movement relative to the tilt tube and having a projecting end, a power steering cylinder fixed relative to the tilt tube, a piston reciprocable within the power steering cylinder, a piston rod having an inner end connected to the piston and having an outer end extending from the steering cylinder, a spool valve assembly including a first member mounted to the outer end of the piston rod, and a second member reciprocably moveable relative to the first member, an elongate bell crank having a first end pivotally connected to the projecting end of the steering ram, having a second end pivotally connected to the second member and being pivotally

Abstract: The marine propulsion device includes a propulsion unit mounted for tilting movement about a generally horizontal tilt axis and for pivotal steering movement about a vertical steering axis, and a power steering system adapted to operably connect an actuator to the propulsion for increasing the steering force applied to the propulsion unit by the actuator. The power steering system is wholly supported on the propulsion unit and includes a hydraulic cylinder-piston assembly having an axis extending in fixed parallel rotation to the tilt axis and including a cylinder, a piston mounted in the cylinder, and an extendable and retractable piston rod connected to the piston, and a control valve connected to a source of pressurized hydraulic fluid for selectively controlling the flow of hydraulic fluid to and from the opposite sides of the piston to extend and retract the piston rod. The control valve includes a valve member and valve housing rotatably and axially movable relative to each other.

Abstract: A marine propulsion device comprising a propulsion unit adapted to be pivotally mounted on the transom of a boat for pivotal movement relative to the transom about a steering axis, the propulsion unit including a rotatably mounted propeller, an engine including a throttle lever, and a shiftable transmission drivingly connecting the engine to the propeller and including a shift lever, a hydraulic shift assist system connected to the shift lever for actuation thereof, a hydraulic throttle assist system connected to the throttle lever for actuation thereof, a hydraulic fluid reservoir, a pump communicating with the reservoir, a supply conduit communicating between the pump and the shift assist system, a supply conduit communicating between the shift assist system and the throttle assist system, and a return conduit communicating between the throttle assist system and the reservoir.

Abstract: A marine propulsion device comprising a propulsion unit adapted to be mounted on the transom of a boat for pivotal movement relative to the transom about a steering axis, the propulsion unit including a rotatably mounted propeller, and an engine drivingly connected to the propeller and including a water jacket, a water pump connected to the water jacket for forcing cooling water through the water jacket to cool the engine, a fluid pump driven by the engine, a conduit communicating between the water jacket and the atmosphere, and a fluid cooler communicating with the conduit to receive cooling water from the water jacket and communicating with the fluid pump for cooling the fluid pumped thereby.

Abstract: An outboard motor comprising a mounting assembly adapted to be fixedly attached to the transom of a boat and including a cylindrical bore defining a steering axis, a propulsion unit including a rotatably mounted propeller, a power head drivingly connected to the propeller, and a steering arm shaft pivotally received in the bore in the mounting assembly for pivotal movement of the propulsion unit relative to the mounting assembly and to the transom about the steering axis, and a friction device mounted on the mounting assembly and frictionally engaging the steering arm shaft for damping oscillation of the steering arm shaft about the steering axis relative to the mounting assembly.

Abstract: A marine propulsion device comprising a propulsion unit adapted to be mounted on the transom of a boat for pivotal movement relative to the transom about a generally vertical steering axis, and about a generally horizontal tilt axis, the propulsion unit including a rotatably mounted propeller, an engine drivingly connected to the propeller, and a wall at least partially defining a cooling water jacket and having therein an opening communicating with the water jacket, and a fluid cooler extending through the opening and including a portion extending internally of the water jacket and having therein a fluid passage adapted to communicate with a source of fluid to be cooled in the fluid cooler.

Abstract: A marine propulsion device comprising a mounting bracket assembly adapted to be mounted on a boat transom for pivotal movement relative to the boat transom about a generally horizontal tilt axis, a propulsion unit including an internal combustion engine and rotatably connected to the mounting bracket assembly for rotation relative to the mounting bracket assembly about a generally vertical steering axis, and for common pivotal movement with the mounting bracket assembly about the tilt axis, a shroud substantially enclosing the engine, and a duct including a first rigid portion adapted for connection to and through the transom of the boat, and a second rigid portion communicating with and being rotatably connected to the first rigid portion for rotation about the tilt axis, and communicating with and being rotatably connected to the shroud for rotation about the steering axis.

Abstract: The electrical control for a hydraulically-actuated trim and tilt system of a marine propulsion device includes a trim-tilt switch movable between "off", "up" and "down" positions, a motion-actuated position switch movable from a "trim" position to a "tilt" position in response to a tiltable propulsion assembly being pivoted upwardly beyond the upper end of a range of trim positions, a pressure-actuated thrust switch which senses an increase in the hydraulic pressure in part of the hydraulic system due a placement of the piston of the hydraulic actuator under load in response to increasing propelling thrust and which is movable from a "low" thrust position to a "high" thrust position in response to the hydraulic pressure exceeding a predetermined level corresponding to a predetermined propeller thrust level, and a reversible electrical motor driving a reversible hydraulic pump which supplies pressurized hydraulic fluid to the hydraulic actuator.

Abstract: A marine propulsion device adapted for mounting to a boat transom and comprising a propulsion unit, a swivel bracket connecting the propulsion unit to the boat transom for pivotal movement of the propulsion unit relative to the boat transom about a steering axis, and an extendable and contactable steering link pivotally connected to the boat transom and to the propulsion unit for rotating the propulsion unit about the steering axis. The device also comprises an operator actuated extendable and contractable control link connected to the boat transom and to the propulsion unit and operably connected to the steering link for selectively effecting extension and contraction of the steering link in response to operator actuation of the control link.

Abstract: Disclosed herein is a marine propulsion installation comprising a marine propulsion device including a transom bracket having a mounting portion fixed to the rear of a boat transom below the upper edge thereof, and a pair of laterally spaced arms extending upwardly from the mounting portion and including respective upper ends located rearwardly of the boat transom and above the upper edge thereof, a swivel bracket comprising a mounting portion and a pair of laterally spaced arms extending upwardly from the swivel bracket mounting portion and including respective upper ends, a tilt pin connecting the upper ends of the transom bracket and swivel bracket arms to provide for pivotal movement of the swivel bracket relative to the transom bracket about a tilt axis which is horizontally located rearwardly of the transom and above the upper edge thereof, a propulsion unit including an internal combustion engine and a propeller mounted for rotation and driven by the engine, and a king pin connecting the propulsion uni