Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: To provide a small watercraft capable of suppressing vibration and noise of a vessel body, a jet pump is mounted to a hull via a thrust plate. A dynamic damper is disposed as an adjunct at a plate mounting portion that attaches the thrust plate to the hull. More specifically, the thrust plate is first mounted to the hull. Then, with a flange portion of the jet pump pressed up against a rear surface of the thrust plate, a second bolt is screwed in toward the thrust plate from an outward side of the hull. The jet pump is thereby attached to the rear surface of the thrust plate.

Abstract: 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.

Abstract: To provide a small watercraft capable of suppressing vibration and noise of a vessel body, a jet pump is mounted to a hull via a thrust plate. A dynamic damper is disposed as an adjunct at a plate mounting portion that attaches the thrust plate to the hull. More specifically, the thrust plate is first mounted to the hull. Then, with a flange portion of the jet pump pressed up against a rear surface of the thrust plate, a second bolt is screwed in toward the thrust plate from an outward side of the hull. The jet pump is thereby attached to the rear surface of the thrust plate.

Abstract: An intake system for a vehicle engine includes an air cleaner and a plurality of throttle bodies. The air cleaner encases an air cleaner element in an air cleaner housing for filtering air flowing from an unfiltered air chamber to a filtered air chamber of the air cleaner housing. The throttle bodies control the amount of air supplied from the filtered air chamber to a cylinder head. Operating noise of the throttle bodies is minimized by situating the throttle bodies within the air cleaner housing. Operating noise of fuel injectors associated with the throttle bodies is minimized by situating the fuel injectors within the air cleaner housing.

Abstract: An intake system for a vehicle engine includes an air cleaner and a plurality of throttle bodies. The air cleaner encases an air cleaner element in an air cleaner housing for filtering air flowing from an unfiltered air chamber to a filtered air chamber of the air cleaner housing. The throttle bodies control the amount of air supplied from the filtered air chamber to a cylinder head. Operating noise of the throttle bodies is minimized by situating the throttle bodies within the air cleaner housing. Operating noise of fuel injectors associated with the throttle bodies is minimized by situating the fuel injectors within the air cleaner housing.

Abstract: A reed valve includes a vibration suppressing member for suppressing transmission of vibration, caused due to opening and closing operations of a reed piece, to a fixed mounting portion of an engine part to which the reed valve is mounted. The vibration suppressing member includes an elastic annular projection formed on at least one of an outer peripheral surface of a gasket fitted around an outer peripheral edge of a valve plate and a pair of upper and lower surfaces of the gasket. The elastic annular projection is elastically engaged with the fixed mounting portion when the mount portion of the valve plate is mounted to the fixed mounting portion.

Abstract: A reed valve includes a vibration suppressing member for suppressing transmission of vibration, caused due to opening and closing operations of a reed piece, to a fixed mounting portion of an engine part to which the reed valve is mounted. The vibration suppressing member includes an elastic annular projection formed on at least one of an outer peripheral surface of a gasket fitted around an outer peripheral edge of a valve plate and a pair of upper and lower surfaces of the gasket. The elastic annular projection is elastically engaged with the fixed mounting portion when the mount portion of the valve plate is mounted to the fixed mounting portion.

Abstract: A buffer device for reducing the impact and noise of the coupling of a roller chain and sprocket. A groove is provided adjacent the teeth of a sprocket which receives a buffer ring. The buffer ring includes an outer resiliently compressible ring and an inner spring-like ring which is not compressible, but which is capable of resilient deformation. The buffer ring is sized to very loosely fit in the groove to avoid wear concentration. The outside diameter of the buffer ring is larger than the inscribed circle of the link plates of the roller chain engaged with the sprocket.