Abstract: A number of embodiments of outboard motors employing direct fuel injection systems having high pressure fuel pumps that are mechanically driven off of the engine crankshaft. A wide variety of driving arrangements are disclosed which include direct and indirect drives and drive that employs flexible transmitters and other types of driving arrangements. Furthermore, the pump operating mechanisms are also provided with lubricating systems that will permit servicing of the lubricant even though the drive arrangement may be positioned outside of the crankcase of the engine. Furthermore, arrangements for mounting various components including the fuel pump and other engine-driven accessories in an outboard motor are shown.

Abstract: A marine propulsion engine abnormal condition sensing arrangement, specifically a low oil pressure sensor, that is effective to permit a low cost sensor by using a separate power supply circuit that need not pass through the main watercraft control in order to drive the switch. The warning device that is operated by the switch is provided with a separate power supply so that its characteristics need not determine the current that is supplied to the sensor.

Abstract: The present invention is an ignition control system controlling ignition firing timing of an ignition element associated with an engine. The engine includes an output shaft powering a water propulsion device, an intake system including a throttle valve, and a sensor providing an output signal corresponding to each revolution of the output shaft. The ignition control system calculates a base ignition firing timing from a time between successive previous output signals, and determines if a low-temperature idle condition of engine exists from the sensed throttle angle and coolant temperature. If such condition exists, the ignition control system also determines a compensation value to compensate ignition timing to either the advance or delay side to generally match a target engine speed for a given coolant temperature, and modifies the basic ignition firing timing by the compensation value.

Abstract: A water cooled four-cycle outboard motor having an improved flushing system that permits flushing of the cooling system without removal of even the protective cowling and which permits flushing to be accomplished with a minimum of water usage. The flushing connection is coupled with a tell tale connection to provide a simple, but highly effective construction. In addition, the system effectively cools the engine and a temperature sensor is positioned in an area where it will be protected from overheating.

Abstract: An outboard motor having a multi-cylinder four-cycle, internal combustion engine as a power plant. An improved crankcase ventilating system is provided wherein the crankcase ventilating gases follow a circuitous path through the crankcase chamber, camshaft chambers and then to the intake system through an extended conduit passing over the exhaust manifold so as to reduce the emissions of hydrocarbons. The intake system is designed to preclude uneven distribution of the ventilating gases. The intake system also is comprised of a plenum device, a plurality of runners and throttle bodies and an intake manifold that are attached as a unit to the rest of the engine body. Portions of this unit are formed from a synthetic resin.

Abstract: A shock absorbing arrangement integrates in a compact manner into a fluid motor of a tilt cylinder, and consequently is particularly well suited for a small outboard drive that may only have a slimed tilt cylinder. The shock absorbing arrangement is provided in a piston for permitting flow from the first chamber to the second chamber upon the application of a predetermined force tending to cause the outboard drive to tilt-up. The shock-absorbing mechanism comprises a check valve assembly accommodated in a hollow space that is formed in the piston and is closed by a plug attached to the piston. A piston rod extends through the first chamber from the piston and is separately formed with the piston. The piston rod includes a passage that communicates with the hollow formed in the piston. A diameter of the passage provided in the piston rod is larger than the diameter of a valve seat for the check valve assembly in order to reduce fluid friction loss across the shock-absorbing valve assembly.

Abstract: An outboard motor comprising a water propulsion device and a cowling housing an internal combustion engine is disclosed. The engine has a body defining at least one combustion chamber and an output shaft arranged to drive the water propulsion device. The cowling has a front end and a rear end. The motor includes a handle which generally encircles at least a portion of the cowling, the handle having at least one gripping portion at the front or rear end of the cowling.

Abstract: A marine propulsion control that permits the use of transmission braking for a watercraft without the likelihood of engine stalling by increasing engine speed during this condition. Nevertheless normal idle speeds can be maintained when running in neutral. This is accomplished with a single lever control.

Abstract: A number of embodiments of engine control for marine application wherein the engine is called upon to operate for long periods at speeds substantially below normal idling speed. This is encountered when trolling. The arrangement includes a system for substantially retarding the spark to assist in shifting and also to maintain stability when running at these low speeds. Adjustments may be made in air flow and fuel supply amounts so as to further augment the smooth running and avoid stalling under these trolling conditions. Various control routines for achieving appropriate ignition timing under the widely varying instantaneous speeds during trolling are also disclosed.

Abstract: An outboard motor having a multi-cylinder four-cycle, internal combustion engine as a power plant. The engine is provided with an oil reservoir in the upper portion of the drive shaft housing and lower unit. Oil is drained back to this oil reservoir by separate drain passages formed in the cylinder head and in the crankcase. In addition, an improved crankcase ventilating system is provided wherein the crankcase ventilating gases follow a circuitous path through the crankcase chamber, camshaft chambers and then to the intake system so as to reduce the emissions of hydrocarbons.

Abstract: A cowling arrangement for an outboard motor for use in powering a watercraft is disclosed. The motor has an engine and a water propulsion device, the engine having an output shaft arranged to drive the water propulsion device. The cowling defines an engine compartment in which the engine is positioned and an air chamber having an inlet. The cowling comprises a cover and an air chamber base. The air chamber base is connected to the cover in a sealed manner and divides the engine compartment from the air chamber and includes a duct which extends upwardly into the air chamber. The air chamber base which defines an air passage leading from the chamber to the engine compartment. The air chamber base defines a surface sloping in a direction of a drain through the air chamber, whereby water drawn through the inlet is drained therefrom.

Abstract: An outboard motor includes an improved engine layout to provide a compact power head while simplifying the arrangement of components on the engine. In one mode, an induction system of the engine includes a carburetor that is arranged over a cylinder head. An intake pipe connects the carburetor to an intake port of the cylinder head. The pipe has generally a U-shape and loops around the upper side edge of the cylinder head. An air intake device is arranged upstream of the carburetor to supply air thereto. The air intake device includes a downward facing air intake opening that is located along a side of the engine below the upper end. This arrangement of the induction system that extends over the upper side of the engine produces a compact assembly without overly complicating the arrangement of other components on the engine, such as, for example, a manual starter device.

Abstract: An outboard motor throttle and transmission control that employs a bowden wire mechanism for transmitting control signals from the tiller handle to the engine throttle and transmission control. The control handle is pivotally mounted on the front end of a tiller arm and the wire actuators exit the control handle and enter the protective cowling on opposite sides of a longitudinal center plane or on opposite sides of the protective cowling so as to increase the length of the wire actuators in this area so as to facilitate their bending without kinking.

Abstract: One embodiment of an engine has an electrical system generally comprising a charge circuit and an ignition circuit. A primary power supply circuit connects the charge circuit and the ignition circuit through a non-contact switch circuit. The non-contact switch is adapted to connect the primary power supply circuit to the ignition circuit when the engine is started. A secondary power supply circuit is coupled to at least one electrical component and to the ignition circuit. The secondary power supply circuit has a main switch and a fuse arranged upstream of the main switch. Upon closing the main switch, the engine is started and the primary power supply circuit and the associated non-contact switch are closed. Another embodiment of the engine has an electrical system which adds control of a fuel injector circuit. The fuel injector circuit is in electrical communication with the ignition circuit and a switching circuit which controls the ignition circuit and the fuel injector circuit.

Abstract: The present invention is an ignition control system for an engine having an ignition system. The ignition control system is arranged to determine if a speed of the engine is decreasing at greater than a predetermined rate, and if so, to initiate an ignition timing compensation mode in which target engine speeds during the time of deceleration are set. These target engine speeds are compared to the actual engine speed and a firing timing of the ignition is advanced if the actual engine speed is less than the target speed and the firing timing of the ignition system is delayed if the actual engine speed exceeds the target speed.

Abstract: An outboard motor cooling system wherein the coolant is circulated through the various cooling jackets so that it first flows into proximity with at least a portion of the exhaust system cooling jacket and then into the cooling jackets of the main engine body that cool the cylinder bore and combustion chamber. Sacrificial anodes are positioned both in the main engine body cooling jacket and in the exhaust system cooling jacket. In addition, a temperature sensor is positioned in a low portion of the cooling jacket and where the water has passed through the exhaust cooling jacket and before it enters the main engine body cooling jacket so as to provide accurate temperature indication while protecting the temperature sensor from excess temperature conditions particularly after engine shut off.

Abstract: Several embodiments of outboard motors having four cycle internal combustion engines wherein one or more fuel pumps are directly driven by the lobes of the camshafts that operate the valves of the engine. This provides a very compact assembly, permits latitude in the location of the fuel pump or pumps and also minimizes the number of driving connections that are required.

Abstract: A crankcase ventilation system is provided for an outboard motor having a cowling and a water propulsion device, an internal combustion engine positioned in the cowling and arranged to propel the water propulsion device. The engine having at least one combustion chamber, a crankcase chamber into which blow-by air and fuel from the combustion chamber passes, a lubricating system including an oil filter and an ignition system including an ignition element for initiating combustion in said combustion chamber. The crankcase ventilation system includes an air intake member defining an intake chamber, at least one air intake port providing a source of air for the engine communicating with the intake chamber and an output port in fluid communication with the intake chamber for delivery of the air to the engine from the intake chamber. At least one blow-by port directs blow-by mixture from the crankcase chamber into the intake chamber at a point on the air intake member between the intake port and the output port.

Abstract: A cowling latch for an outboard motor having an upper cowling having a lower surface and a lower cowling having an upper surface is disclosed. The cowling latch comprises a first latching member connected to the upper cowling and a second latching member connected to the lower cowling. The second latching member is moveable between a first position in which it engages the first latching member for connecting the upper and lower cowlings and a second position in which it does not engage the first latching member. The second latching member comprises a first latching member engaging part movably mounted with respect to a support, the support positioned below the upper surface of the lower cowling.