Honda Motor Co., Ltd.

Masatsugu Matsumoto

Yoshiaki Noda

Toshinori Hanai

Yosuke Hoi

Takayoshi Miura

Tsuyoshi Kumasaka

Yoshitaka Hayama

Junji Higashiyama

Noboru Yokoya

Takeshi Kimishima

Hajime Shogase

Atsushi Kusuda

Yasunori Okazaki

Takeshi Koyabu

An exhaust system for a small watercraft for effectively reducing exhaust noise and allowing a high output of an engine to be easily obtained at the time of high speed operation. An exhaust outlet of an exhaust pipe extending from an engine provided in a watercraft body is disposed at a position that allows it to sink in the water at the time when a travel speed of the watercraft body is a predetermined speed or less. The exhaust outlet is raised above the water at the time when the travel speed of the watercraft body exceeds the predetermined speed. An open surface of the exhaust outlet is offset toward a side wall surface of a pump chamber from a center of a jet pump in the pump chamber and is made oblique toward the side wall surface toward which the open surface of the exhaust outlet is offset.

Exhaust system for small watercraft

An exhaust apparatus for a small boat for reducing exhaust noise. A water muffler is provided at a midsection of the exhaust pipes extending from an engine which is provided in a boat body. An interior of the water muffler is partitioned into an expansion chamber and a resonator chamber with a front exhaust pipe connected to the engine and a rear exhaust pipe opening out of the boat being interlinked with the expansion chamber. The resonator chamber is directly connected to the midsection of the rear exhaust pipe via a connecting pipe. The water muffler is arranged in a longitudinal direction that is oriented in the fore-and-aft direction so as to extend along the side of a pump chamber in which a jet pump driven by the engine is arranged. A second resonator chamber is arranged along the water muffler on the outer side of the water muffler.

Exhaust apparatus for small boat

An air intake structure for a small watercraft for ensuring the capacity of an inter-cooler and for connecting the inter-cooler to a supercharger by a simply shaped communicating portion. In an air intake structure for a small watercraft, an intake passage and an exhaust passage can be disposed on the left side and the right side, respectively, of a plurality of cylinders. A turbocharger is disposed rearwardly of the engine with the turbocharger is connected to an intake passage via an inter-cooler. In addition, the inter-cooler is disposed rearwardly of the engine, with the distribution passage being disposed forwardly of and on the left side of the inter-cooler so as to extend in the forward and rearward direction. The inter-cooler is connected to the rear end of the distribution passage with an intake pipe contiguous to cylinders being bent rearwardly along a side surface of the engine body.

Air intake structure for small watercraft

To provide an exhaust structure for a small watercraft that can cool exhaust gas, reduce the size and weight, and thereby cost of a backflow prevention chamber. An exhaust structure for a small watercraft is configured to be able to cool exhaust gas in the course of leading it to the outside when the exhaust gas of an engine is led to the outside for discharge. This exhaust structure includes a water muffler containing water therein. A backflow prevention chamber is disposed above the water muffler and adapted to prevent water from entering the side of the engine from the side of the water muffler. The backflow prevention chamber is provided with a cooling water injecting portion adapted to spray cooling water to the exhaust gas in an internal space. An outlet is formed in the bottom portion of the backflow prevention chamber to communicate with the water muffler.

Exhaust structure for small watercraft

An air intake device for a watercraft adapted to suppress noise generating from an intake system of an engine and can obtain good intake efficiency. The air intake device includes intake ports opening to a side surface of the engine, and an air cleaner located on the rear side of the engine. An outlet of the air cleaner is connected through an intake passage to the intake ports of the engine. An air duct extends from an inlet of the air cleaner along the side surface of the engine to the position corresponding to the front end of the engine. The air duct has a front opening that faces downward.

Air intake device for watercraft

An open/close valve can decrease the exhaust resistance as much as possible in a usual operation. An open/close valve includes a valve casing and a valve element that is housed in the valve casing in a vertically movable manner. The valve casing includes a cylindrical portion that extends vertically. A through hole is formed in the cylindrical portion. A bottom portion is formed on a bottom of the cylindrical portion. A discharge inlet is formed in an upper portion of the cylindrical portion. The valve element includes a cylindrical body that is arranged along an inner surface of the cylindrical portion and has a height that maintains an opening of the through hole and a seal plate that covers an upper portion of the cylindrical body and has a size capable of closing the exhaust inlet.

Exhaust device of boat

An exhaust system for a small-sized boat which can efficiently reduce exhaust noises in a low frequency band includes a water muffler provided at one location along exhaust pipes extending from an engine disposed in a boat body. The inside of the water muffler is divided into a single expansion chamber and a resonator chamber, and a front exhaust pipe coupled to the engine and a rear exhaust pipe opened to the outside of the boat are connected to the expansion chamber. Between the front exhaust pipe opened to the inside of the expansion chamber and the rear exhaust pipe, a water-controlling plate is provided in an upper side of the expansion chamber.

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Saitama, Japan

Masatsugu Matsumoto