Abstract: A seat cushion includes an edge portion and a three-dimensional fiber structure including core-sheath fusible fibers and skeletal fibers thermally fused at intersections thereof. The sheaths of the core-sheath fusible fibers are made of a thermoplastic elastomer to fuse the intersections and form a bulging portion at each of the fused intersections. The skeletal fibers and the cores of the core-sheath fusible fibers are made of a non-elastomer resin. The skeletal fibers are crimp-processed bulky fibers, and a fineness of the skeletal fibers and a fineness of the core-sheath fusible fibers are in a range of 1 to 200 dtex. The seat cushion has a layered structure including a plurality of layers fused together, each of the layers has the three-dimensional fiber structure, and the seat cushion has a density distribution based on regional variations of the layered structure and a stiffness distribution that depends on the density distribution.

Abstract: A seat cushion includes an edge portion and a three-dimensional fiber structure including core-sheath fusible fibers and skeletal fibers thermally fused at intersections thereof. The sheaths of the core-sheath fusible fibers are made of a thermoplastic elastomer to fuse the intersections and form a bulging portion at each of the fused intersections. The skeletal fibers and the cores of the core-sheath fusible fibers are made of a non-elastomer resin. The skeletal fibers are crimp-processed bulky fibers, and a fineness of the skeletal fibers and a fineness of the core-sheath fusible fibers are in a range of 1 to 200 dtex. The seat cushion has a layered structure including a plurality of layers fused together, each of the layers has the three-dimensional fiber structure, and the seat cushion has a density distribution based on regional variations of the layered structure and a stiffness distribution that depends on the density distribution.

Abstract: A boat includes an engine, an input that receives an input operation performed by an operator, and a controller connected to the input. The controller is powered off when the input does not receive the input operation within a first length of time after the engine is stopped. The controller is not powered off when the input receives the input operation within the first length of time after the engine is stopped.

Abstract: A small watercraft includes an input, a second storage, and a controller. The input receives an operation to switch the small watercraft into one of a plurality of control states, and includes a first storage that stores first control information indicating the one of the plurality of control states associated with the operation received by the input. The second storage stores second control information indicating one of the plurality of control states. The controller is able to write to one of the first and second storages. The input is supplied with electric power by supplying the controller with the electric power.

Abstract: It is difficult to move forward/backward a water jet propulsion boat at very low speed through use of right and left operation elements each provided on a handle. In order to move the boat forward/backward at very low speed through a simple operation, under a state in which neutral operations have been carried out, an operation state of an engine is maintained in an idling state, and a movement position of a jet flow adjustment member including a deflector and a reverse bucket is controlled so as to adjust a difference between a “thrust generated by a forward jet flow component” and a “thrust generated by a backward jet flow component” of a jet flow divided into a forward jet flow and a backward jet flow by the jet flow adjustment member, based on an operation on a third operation element provided independently of the right and left operation elements.

Abstract: A small boat includes an engine, a display that displays a speed setting image of a boat body and an acceleration setting image of the boat body side by side, an operator including a speed setting operator through which an operation of setting a speed set value is received and an acceleration setting operator through which an operation of setting an acceleration set value is received, and an engine controller that controls the engine based on the operations received by the operator.

Abstract: It is difficult to move forward/backward a water jet propulsion boat at very low speed through use of right and left operation elements each provided on a handle. In order to move the boat forward/backward at very low speed through a simple operation, under a state in which neutral operations have been carried out, an operation state of an engine is maintained in an idling state, and a movement position of a jet flow adjustment member including a deflector and a reverse bucket is controlled so as to adjust a difference between a “thrust generated by a forward jet flow component” and a “thrust generated by a backward jet flow component” of a jet flow divided into a forward jet flow and a backward jet flow by the jet flow adjustment member, based on an operation on a third operation element provided independently of the right and left operation elements.

Abstract: A boat includes an engine, an input that receives an input operation performed by an operator, and a controller connected to the input. The controller is powered off when the input does not receive the input operation within a first length of time after the engine is stopped. The controller is not powered off when the input receives the input operation within the first length of time after the engine is stopped.

Abstract: A small watercraft includes an input, a second storage, and a controller. The input receives an operation to switch the small watercraft into one of a plurality of control states, and includes a first storage that stores first control information indicating the one of the plurality of control states associated with the operation received by the input. The second storage stores second control information indicating one of the plurality of control states. The controller is able to write to one of the first and second storages. The input is supplied with electric power by supplying the controller with the electric power.

Abstract: A small boat includes an engine, a display that displays a speed setting image of a boat body and an acceleration setting image of the boat body side by side, an operator including a speed setting operator through which an operation of setting a speed set value is received and an acceleration setting operator through which an operation of setting an acceleration set value is received, and an engine controller that controls the engine based on the operations received by the operator.

Abstract: An engine includes an engine body and an exhaust pipe. The engine body includes a combustion chamber and an oil passage in which lubricating oil flows. The exhaust pipe includes an exhaust passage and an oil jacket. The exhaust passage is linked to the combustion chamber. The oil jacket is linked to the oil passage.

Abstract: An engine includes an engine body and an exhaust pipe. The engine body includes a combustion chamber and an oil passage in which lubricating oil flows. The exhaust pipe includes an exhaust passage and an oil jacket. The exhaust passage is linked to the combustion chamber. The oil jacket is linked to the oil passage.

Abstract: A catalyst for purifying an exhaust gas can include a carrier having a honeycomb structure, an outer pipe for covering a part of the carrier, and a brazing foil for joining the outer peripheral surface of the carrier and the inner peripheral surface of the outer pipe on the downstream side of the catalyst. The catalyst can be fixed to a support flange such that an axial direction of the catalyst coincides with the direction in which an exhaust gas flows through an exhaust pipe. An upstream end of the brazing foil can be aligned with the upstream end of a catalyst fixing part of the support flange. An upstream end of the catalyst fixing part can be positioned upstream of the axial middle of the carrier. The brazing foil can be provided in a portion from the upstream end of the catalyst fixing part to the downstream side of the carrier. The catalyst can be supported at its generally middle part by the support flange.

Abstract: A catalyst for purifying an exhaust gas can include a carrier having a honeycomb structure, an outer pipe for covering a part of the carrier, and a brazing foil for joining the outer peripheral surface of the carrier and the inner peripheral surface of the outer pipe on the downstream side of the catalyst. The catalyst can be fixed to a support flange such that an axial direction of the catalyst coincides with the direction in which an exhaust gas flows through an exhaust pipe. An upstream end of the brazing foil can be aligned with the upstream end of a catalyst fixing part of the support flange. An upstream end of the catalyst fixing part can be positioned upstream of the axial middle of the carrier. The brazing foil can be provided in a portion from the upstream end of the catalyst fixing part to the downstream side of the carrier. The catalyst can be supported at its generally middle part by the support flange.

Abstract: 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.

Abstract: A small watercraft engine having a lubrication system including a lubrication oil reservoir defining a cooling water jacket therein. A cooling system of the engine supplies cooling water to the water jacket. The water jacket includes at least one rib, and preferably a plurality of ribs, to guide the cooling water within the water jacket. The ribs may be arranged to guide cooling water from a lower portion of the water jacket to an upper portion of the water jacket through two or more generally distinct horizontal regions. Preferably, a pair of baffle arrangements are disposed within the oil reservoir. A first baffle arrangement separates the interior space of the reservoir from a breather chamber which communicates with the intake system. A second baffle arrangement is configured to generally retain oil within a lower portion of the reservoir so as to be available to a delivery port, which delivers oil to an oil pump of the engine.

Abstract: A small watercraft engine having a lubrication system including a lubrication oil reservoir defining a cooling water jacket therein. A cooling system of the engine supplies cooling water to the water jacket. The water jacket includes at least one rib, and preferably a plurality of ribs, to guide the cooling water within the water jacket. The ribs may be arranged to guide cooling water from a lower portion of the water jacket to an upper portion of the water jacket through two or more generally distinct horizontal regions. Preferably, a pair of baffle arrangements are disposed within the oil reservoir. A first baffle arrangement separates the interior space of the reservoir from a breather chamber which communicates with the intake system. A second baffle arrangement is configured to generally retain oil within a lower portion of the reservoir so as to be available to a delivery port, which delivers oil to an oil pump of the engine.

Abstract: 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.

Abstract: A small watercraft engine having a lubrication system including a lubrication oil reservoir defining a cooling water jacket therein. A cooling system of the engine supplies cooling water to the water jacket. The water jacket includes at least one rib, and preferably a plurality of ribs, to guide the cooling water within the water jacket. The ribs may be arranged to guide cooling water from a lower portion of the water jacket to an upper portion of the water jacket through two or more generally distinct horizontal regions. Preferably, a pair of baffle arrangements are disposed within the oil reservoir. A first baffle arrangement separates the interior space of the reservoir from a breather chamber which communicates with the intake system. A second baffle arrangement is configured to generally retain oil within a lower portion of the reservoir so as to be available to a delivery port, which delivers oil to an oil pump of the engine.

Abstract: A watercraft has an exhaust system. The exhaust system has a first portion cooled by cooling jackets and a second portion cooled by merged flow. The first portion is coupled to the second portion with a flexible coupling having an undulating surface. An overheat detection system is positioned proximate the flexible coupling. The overheat detection system is arranged to detect a rapid increase in temperature resulting from a blocked cooling jacket. During periods of normal operation, a first temperature reading is detected. During periods of abnormal operation, a rapid increase in temperature indicates a sudden decrease in cooling water within the cooling jacket. Warning signals are emitted to the operator by an overheat prevention unit to advise the operator of the condition.