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 control system for a marine vessel that includes a drive source and an operator that receives an operation is able to switch a control mode of the drive source without providing an additional operator. An operation received by the operator when the drive source is resting is disabled, and a function of switching a control mode of the drive source is assigned to the operation of the operator that is received when the drive source is resting.

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 control system for a marine vessel that includes a drive source and an operator that receives an operation is able to switch a control mode of the drive source without providing an additional operator. An operation received by the operator when the drive source is resting is disabled, and a function of switching a control mode of the drive source is assigned to the operation of the operator that is received when the drive source is resting.

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 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 water jet propulsion watercraft includes a hull having a sealed engine room, an engine installed in the engine room, a jet propulsion unit arranged to be driven by the engine so as to suck in water from around the hull and jet the water, a saddle type seat disposed above the engine room, a first exhaust pipe, an exhaust pipe cooling unit, and a catalyst unit. The first exhaust pipe is attached to a side of the engine inside the engine room, extends rearward from the side of the engine, and is arranged to guide exhaust gas discharged from the engine. The exhaust pipe cooling unit is arranged to cool the first exhaust pipe. The catalyst unit is connected to the first exhaust pipe, is disposed inside the engine room so as to oppose a rear surface of the engine, and is arranged to promote reaction of components contained in the exhaust gas.

Abstract: A water jet propulsion watercraft includes a first exhaust pipe that is fixed to an engine and connected to an exhaust port of the engine. A damper section reduces vibrations from the engine. A catalytic converter unit is connected to the first exhaust pipe. The catalytic converter unit is attached to the engine through the damper section. A second exhaust pipe includes a first flexible pipe having a flexible quality and is connected to the catalytic converter unit. A water lock is fixed to a hull of the watercraft and connected to the second exhaust pipe.

Abstract: A water jet propulsion watercraft includes a hull having a sealed engine room, an engine installed in the engine room, a jet propulsion unit arranged to be driven by the engine so as to suck in water from around the hull and jet the water, a saddle type seat disposed above the engine room, a first exhaust pipe, an exhaust pipe cooling unit, and a catalyst unit. The first exhaust pipe is attached to a side of the engine inside the engine room, extends rearward from the side of the engine, and is arranged to guide exhaust gas discharged from the engine. The exhaust pipe cooling unit is arranged to cool the first exhaust pipe. The catalyst unit is connected to the first exhaust pipe, is disposed inside the engine room so as to oppose a rear surface of the engine, and is arranged to promote reaction of components contained in the exhaust gas.

Abstract: A water jet propulsion watercraft includes a hull having a sealed engine room, an engine installed in the engine room, a jet propulsion unit arranged to be driven by the engine so as to suck in water from around the hull and jet the water, a saddle type seat disposed above the engine room, a first exhaust pipe, an exhaust pipe cooling unit, and a catalyst unit. The first exhaust pipe is attached to a side of the engine inside the engine room, extends rearward from the side of the engine, and is arranged to guide exhaust gas discharged from the engine. The exhaust pipe cooling unit is arranged to cool the first exhaust pipe. The catalyst unit is connected to the first exhaust pipe, is disposed inside the engine room so as to oppose a rear surface of the engine, and is arranged to promote reaction of components contained in the exhaust gas.

Abstract: A water jet propulsion watercraft includes a hull having a sealed engine room, an engine installed in the engine room, a jet propulsion unit arranged to be driven by the engine so as to suck in water from around the hull and jet the water, a saddle type seat disposed above the engine room, a first exhaust pipe, an exhaust pipe cooling unit, and a catalyst unit. The first exhaust pipe is attached to a side of the engine inside the engine room, extends rearward from the side of the engine, and is arranged to guide exhaust gas discharged from the engine. The exhaust pipe cooling unit is arranged to cool the first exhaust pipe. The catalyst unit is connected to the first exhaust pipe, is disposed inside the engine room so as to oppose a rear surface of the engine, and is arranged to promote reaction of components contained in the exhaust gas.

Abstract: A water jet propulsion watercraft includes a hull having a sealed engine room, an engine installed in the engine room, a jet propulsion unit arranged to be driven by the engine so as to suck in water from around the hull and jet the water, a saddle type seat disposed above the engine room, a first exhaust pipe, an exhaust pipe cooling unit, and a catalyst unit. The first exhaust pipe is attached to a side of the engine inside the engine room, extends rearward from the side of the engine, and is arranged to guide exhaust gas discharged from the engine. The exhaust pipe cooling unit is arranged to cool the first exhaust pipe. The catalyst unit is connected to the first exhaust pipe, is disposed inside the engine room so as to oppose a rear surface of the engine, and is arranged to promote reaction of components contained in the exhaust gas.

Abstract: A water jet propulsion watercraft includes a first exhaust pipe that is fixed to an engine and connected to an exhaust port of the engine. A damper section reduces vibrations from the engine. A catalytic converter unit is connected to the first exhaust pipe. The catalytic converter unit is attached to the engine through the damper section. A second exhaust pipe includes a first flexible pipe having a flexible quality and is connected to the catalytic converter unit. A water lock is fixed to a hull of the watercraft and connected to the second exhaust pipe.

Abstract: An engine has a charging system in which pressurized air is supplied to an intake side of the engine through an intake air passage. An induction passage branches and extends from the middle of the intake air passage and is provided with a control valve. The induction passage is in communication with an exhaust passage. The induction passage supplies secondary air to the exhaust passage through the control valve to treat the engine's exhaust gas.

Abstract: A water jet propulsion boat is constructed such that a fuel pressure detection device is free from a detection error or breakdown and a restart ability of an engine is protected against malfunction. A fuel tank is provided in a boat body of the water jet propulsion boat through vibration absorbing members. A fuel pump unit including a fuel pump is provided in the fuel tank. A fuel pressure sensor is provided in the fuel pump unit. An electric control device stops the fuel pump if the value detected by the fuel pressure sensor is out of the normal value range. Additionally, an electric control device stops operation of the fuel pump if the fall sensor detects the overturning of the boat body and if the detected value of the fuel pressure sensor is out of the normal value range. A regulator and a filter are provided to the fuel pump unit.

Abstract: A misfire detecting device is provided for a water jet propulsion watercraft in which a propulsion unit operates through an operation of an engine to propel the water jet propulsion watercraft. The misfire detecting device includes injectors arranged to inject fuel into the engine under a fuel injection amount adjusting control implemented by an electric control device, ignition plugs arranged to ignite the fuel injected into the engine from the injectors to operate the engine, an oxygen sensor arranged to detect that a misfire occurs in the engine, a warning lamp and buzzer arranged to inform that the misfire occurs, etc. The misfire detecting device prevents the warning lamp and the buzzer from informing the warning if the misfire is caused through the control by the electric control device.

Abstract: A boat includes a connection structure that connects couplings via a transfer shaft on a rear end portion of a crankshaft extending rearward from an engine. The crankshaft and the transfer shaft are connected by screwing an external thread and a front internal thread, and the transfer shaft and the couplings are connected by screwing an external thread and an internal thread. There are provided an inner bolt that strengthens the connection between the external thread and the front internal thread, an end bolt that strengthens the connection between the transfer shaft and the couplings, and an outer nut that strengthens the connection between the crankshaft and the transfer shaft. The boat can prevent movement between the crankshaft and an intermediate member and between the intermediate member and a coupling both in a rotational direction and in an axial direction without causing an increase of processing time or processing cost.

Abstract: An exhaust gas sensor inhibits a detecting part of an exhaust gas sensor from being exposed to water and has high detection accuracy and high durability. The exhaust gas sensor has a sensor body and a protective cover. The sensor body has an outer housing. The outer housing has a plurality of gas inlets. A gas detection element for detecting a component of the exhaust gas (e.g., oxygen) disposed within the outer housing. The protective cover has a cylindrical shape and has a plurality of protrusions at its opposing ends. The protrusions provide a tight fit with the outer housing. The protective cover is attached to the outer periphery of the outer housing without closing gas inlets formed through the outer cylinder by press-fitting the outer cylinder into the protective cover.

Abstract: An abnormality detection device of a fuel pump reduces costs and prevents detection error or breakdown by making the fuel pressure sensor unnecessary. The abnormality detection device includes an abnormality detection circuit, a fuel pump driving voltage detection unit to detect the voltage value of an abnormality detection circuit, and a meter. The abnormality detection circuit is constituted by the circuit including a resistance disposed between a battery side of the fuel pump motor to drive the fuel pump and a ground side. If the voltage value detected by the fuel pump driving voltage detection unit is larger than the upper limit or lower than the lower limit of the normal range, the warning lamp of the meter flashes and a buzzer makes an alarm sound. The abnormality detection circuit is housed in the fuel pump module disposed in the fuel tank.

Abstract: An engine includes a charging system in which pressurized air is supplied to an intake side of the engine through an intake air passage. An induction passage branches and extends from the middle of the intake air passage and is provided with a control valve. The induction passage is in communication with an exhaust passage. The induction passage supplies secondary air to the exhaust passage through the control valve to treat the engine's exhaust gas.