Sanshin Kogyo Kabushiki Kaisha

Yamaha Marine Kabushiki Kaisha

Tetsuya Ishino

Kazumasa Ito

Yoshihiro Gohara

Naoki Kinomoto

Chihiro Matsumoto

Yoshihide Fukuda

A cooling system particularly suited for use in a small watercraft, which supplies coolant to, and evacuates coolant from, an engine of the watercraft. The engine includes an engine body defining at least one water jacket therein. An engine coolant supply passage desirably routes the coolant into thermal communication with a portion of an exhaust system, such as an exhaust manifold, before supplying the coolant to the water jacket of the engine. When the engine is shut off, coolant is permitted to drain from the water jacket through a drain passage. The drain passage is connected to the coolant supply passage at a position upstream from the exhaust system such that coolant draining from the engine travels in a reverse direction through the supply passage and is drained from the watercraft cooling system. Upon normal operation of the engine, a restriction orifice within the drain passage permits only a relatively small amount of coolant to be supplied to the engine water jacket, without being routed into thermal communication with the exhaust system.

Cooling system for marine engine

An induction system for a watercraft is configured to guide air into an engine disposed within the watercraft for combustion therein. The induction system includes an inlet assembly. The inlet assembly includes various constructions for enhancing water preclusive effects.

Air induction system for small watercraft

An induction system for a watercraft includes a first intake air chamber communicating with at least one combustion chamber of an engine of the watercraft, and a second intake air chamber communicating with the first intake air chamber via a conduit. The second intake air chamber may be arranged in various orientations and/or with various other features which improve attenuation of induction noises and/or the preclusion of water from entering the engine through the induction system.

A jet propelled watercraft having an improved extension assembly for dampening pulsations from the impeller of the jet propulsion unit and also an improved exhaust system having a separate idle discharge for permitting lower idle speeds without restriction of the idle exhaust gas flow.

Jet propulsion system for watercraft

A jet propelled watercraft having an improved extension assembly for dampening pulsations from the impeller of the jet propulsion unit and also for mounting the jet propulsion unit. The structure simplifies the overall assembly and permits individual tuning with conventional units.

A jet propulsion system for a small watercraft including an arrangement for isolating the sound of water flowing through the water inlet portion of the jet propulsion unit from the occupants of the watercraft. This silencing is provided by providing a double wall on at least the portion of the jet propulsion unit water inlet portion juxtaposed to the passenger compartment to provide an insulating jacket. Water may be filled in the insulating jacket and this water can be derived by filling it with the coolant which is circulated through the engine.

Growing community of inventors

Shizuoka, Japan

Tetsuya Ishino