Sanshin Kogyo Kabushiki Kaisha

Yamaha Hatsudoki Kabushiki Kaisha

Yamaha Marine Kabushiki Kaisha

Seiji Inoue

Ryoichi Nakase

Masanori Takahashi

Masayoshi Nanami

Hiroaki Fujimoto

Seiichi Tanaka

Isao Kanno

Yoshikazu Nakayasu

Masahiko Katoh

Toshikatsu Koike

Norimichi Harada

Hidekazu Takayasu

Minoru Kawamura

Hiroaki Outani

Kanichi Tsunamoto

A watercraft has an engine that is controlled to reduce the likelihood of engine damage and rider discomfort when the watercraft engine speed is rapidly increased due to a lack of load on the propulsion unit. The engine is controlled by a method that detects engine speed and reduces the power output of the engine by varying degrees or restores the power output of the engine by varying degrees depending on the speed of the engine relative to plural predetermine speeds.

Fuel injection control for marine engine

A composite piston and method for forming such a piston for a reciprocating machine such as an internal combustion engine. A blank is formed from a pair of dissimilar alloys, one of which has substantially greater properties such as strength or abrasion resistance. The blank is formed by a process whereby he two materials are initially bonded and extruded into a composite blank. The blank is forged into a piston in such a way that the two materials are bonded together in the forging process. The higher strength and/or abrasion resistance material forms at least a part of the outer surface of the piston in areas where the better properties are required. The other material backs up the higher strength or hardness material in necessary areas so as to provide an integral structure that has lightweight, low costs and nevertheless the desired properties.

Method of manufacturing piston

A number of embodiments of cooling systems for marine propulsion units having water cooled internal combustion engines in which the cooling jacket of the engine is at least partially positioned below the level of the water in which the watercraft is operating. The described embodiments all permit draining of the engine cooling jacket when it is not being run. In some embodiments, the drain valve also controls the communication of the coolant from the body of water in which the watercraft is operating with the engine cooling jacket. Various types of pumping arrangements are disclosed for pumping the bilge and automatic valve operation is also disclosed.

Cooling system for marine propulsion engine

An improved air intake passage arrangement for use on an internal combustion engine is disclosed wherein intake passages are integrated with the crankcase such that an outer wall of the crankcase defines an inner wall of the intake passages. This construction minimizes the size of the engine and promotes heating of the air flowing within the intake passages. In addition, depending upon the location of the fuel supply lines, the air intake structure of the present invention can enhance the vaporization of the fuel sprayed therein.

Air intake passage arrangement for a two-cycle engine

Several embodiments of fuel injection systems for two cycle internal combustion engines wherein fuel is injected into a conduit for delivery into the combustion chamber through a port in the cylinder liner. A nozzle insert is positioned in the conduit and has a restricted opening that forms the discharge through which fuel and gas under pressure are supplied to the combustion chamber for facilitating servicing and replacement.

Fuel injection system for the two cycle engine

An exhaust silencing system for a two-cycle ported engine including an expansion chamber that communicates with the cylinder through a communication port that is opened before the exhaust port of the engine is opened so as to permit the exhaust gases to expand and reduce the noise of the engine. The communication port is either fully opened before the exhaust port is initially opened so as to achieve maximum silencing and/or is fully closed before the exhaust port is fully closed so as to avoid loss of effective compression pressure.

Exhaust silencer system for two-cycle engine

An arrangement for insuring that an internal combustion engine of an outboard motor will operate efficiently under all trim adjusted conditions of the outboard motor. The trim angle is sensed and the fuel delivery system is adjusted to provide good running in response to the trim condition. Additionally, embodiments are disclosed wherein the fuel delivery system is also adjusted during initial starting so as to provide adjustment of the fuel delivery in response to both the starting condition and the trim condition. Both carbureted and fuel injected systems are disclosed.

Fuel supplying system for engine of outboard motor

A number of embodiments of outboard motor constructions wherein an arrangement is provided for precluding inadvertent operation of the manual starting handle. In each embodiment, this is achieved by means of a safety member that precludes access to the starter handle. In some embodiments, this is achieved by means of a cover member which blends into the cowling and which protects the starter handle while in another embodiment, it is provided by a latch embodiment. In some embodiments, there is also a lubricant storage tank that has its fill cap accessible through the opening of the protective cover.

Protector for the starting grip of outboard motor

Several embodiments of additional fuel supply systems for internal combustion engines that supply supplemental fuel in addition to the normal charge forming device to satisfy certain specific requirements such as cold starting and cold running. In each embodiment, a separate fuel pump is provided for the supplemental fuel discharge but it is contained within and operated by the same operator of the main fuel pump for supplying fuel to the main fuel discharge. In some embodiments, the fuel pump is downstream of the supplemental fuel control and in other embodiments it is upstream of it. In one embodiment, the fuel pump and the supplemental control are all formed in the same housing.

Fuel supplying system for internal combustion engine

An arrangement for insuring that an internal combustion engine of an outboard motor will operate efficiently under all trim adjusted conditions of the outboard motor. The trim angle is sensed and an engine system such as the timing is adjusted to provide good running in response to the trim condition. Additionally, an embodiment is disclosed wherein the ignition timing is also adjusted during initial starting so as to provide adjustment of the ignition in response to both the starting condition and the trim condition.

Ignition timing control for outboard motor

A small watercraft having a number of embodiments of exhaust systems into which coolant from the engine are discharged and which insure that water cannot enter the exhaust ports in the event the watercraft becomes displaced. In all embodiments, a water accumulating volume surrounds the discharge end of the exhaust pipe within an expansion chamber for trapping water in the event the watercraft becomes displaced from its normal condition and for return of the water therefrom upon erection of the watercraft. In a number of embodiments, gravity operated normally open control valves are also provided for closing the end of the exhaust pipe in the event the watercraft becomes displaced from its normal upright condition so as to insure that water cannot enter the exhaust ports of the engine.

Exhaust system for small vessel

Several embodiments of jet propelled water vessels wherein the bull and jet propulsion unit cooperate to form an inlet opening so that the outer housing of the jet propulsion unit need not itself form the inlet. This facilitates servicing since the water inlet need not be removed along with the jet propulsion unit for servicing and minimizes the likelihood of damage to the inlet duct and support for the impeller shaft.

Water jet propelling vessel

An arrangement for insuring that an internal combustion engine of an outboard motor will operate efficiently under all trim adjusted conditions of the outboard motor. If it is sensed that a change in trim angle will adversely effect the running, for example, by varying the air/fuel ratio, the timing is adjusted to provide good running in response to the trim condition.

Ignition timing control system for outboard engine

A number of embodiments of silencing devices for marine propulsion units using acoustical lenses that are positioned across either the air inlet device, the air exhaust device or both. The acoustical lenses direct the sound waves in such a way so as to effect silencing while, at the same time, ensuring that water will not enter the engine combustion chambers. The invention is shown in conjunction with both outboard motors and inboard mounted engines.

Noise reducing device for marine propulsion

A watercraft incorporating improved warning devices for providing a warning signal in response to a abnormal condition. The abnormal condition may be either the condition when a rider is no longer present on the watercraft or when the watercraft assumes a non-normal running condition such as being capsized or inverted. In some instances, the warning is provided by a flag, a light, by a warning jet spray of water and, in others, by an audible signal. The warning may be combined so that more than one type of warning is given in response to an abnormal condition.

Growing community of inventors

Hamamatsu, Japan

Seiji Inoue