Abstract: A personal watercraft includes a hull and an engine. The hull defines an engine compartment and the engine is disposed within the engine compartment. A waterproof electrical component container is disposed in the engine compartment. The container can include two internal compartments, one being more water-tight than the other. The container can also include an aperture defined in one of the external surfaces of the container, through which an electrical component inside the container can be accessed when the aperture is open.

Abstract: To provide an output power shaft structure for a personal watercraft which is superior in durability. A shaft of a propulsion device is connected to a rear end of a crankshaft of an engine, which is carried on a watercraft body such that the crankshaft thereof is directed in a longitudinal direction of the watercraft body, on an extension line of the crankshaft. A rear end of the crankshaft is disposed in an engine case, and an output power shaft separate from the crankshaft is connected to the rear end of the crankshaft. The shaft of the propulsion device is connected to a rear end of the output power shaft. The rear end of the crankshaft and a front end of the output power shaft are connected to each other in a transmission chamber in which a transmission mechanism for transmitting power of the crankshaft to a camshaft is provided at a rear portion of the crankshaft. A driving sprocket wheel of the transmission mechanism is provided on the output power shaft.

Abstract: An engine suitable for mounting in a small planing boat, which both lowers the center of the gravity of the boat, and enables a degree of freedom in arranging accessories. Balancers are arranged on the left and on the right of a crankshaft on a parting face of an engine. The engine is mounted in the body of the small planing boat surrounded by a hull and a deck. A starter motor and an idle gear of one balancer are arranged on the side opposite the starter motor, with the crankshaft between them. Also disposed between the idle gear and the starter motor is a cylinder. An oil tank is provided at the front of the engine, and two oil supply passages leading to the balancer supports are formed in the case of the oil tank.

Abstract: A personal watercraft with an engine and a supercharger, in which a speedy, positive operation of the supercharger is ensured. The system includes an engine for driving a jet propelling pump provided in a watercraft body formed by a hull and a deck in such a manner as to extend in a length direction of the watercraft body. An oil pump is provided on the front side of the engine and a supercharger 140 is provided on the rear side of the engine. The supercharger and an end portion of a main gallery communicate with each other via an oil supply pipe. Oil supplied to the supercharger is used for lubricating a bearing portion of the supercharger. Further, the oil is supplied to an oil jacket formed in a bearing casing of the supercharger to cool the bearing casing. A one-way valve is interposed in an oil return pipe which communicates to an oil outlet of the supercharger.

Abstract: Disclosed is a personal watercraft which is equipped with an engine designed in such a way that, even when the engine is splashed with water, its ignition plugs will not get wet and the heat generated from the engine or exhaust pipe will not act on, e.g., a riding seat. The personal watercraft includes a multi-cylinder engine having a crankshaft extending along its longitudinal direction and a water jet pump driven by the engine. The water jet pump pressurizes and accelerates water, and ejects the water from an outlet port opened rearward. The watercraft is propelled as a reaction of the ejecting water. An air filter box is so disposed as to overlie a cylinder head of the engine, thereby covering substantially at least the ignition plugs attached to the cylinder head.

Abstract: A personal watercraft (PWC) is provided with a hull having an inner surface. An engine and jet propulsion unit are mounted to the hull and constructed and arranged to propel the PWC. A starboard support post extends generally upwardly from a starboard side of the inner surface of the hull and provides a starboard deck supporting surface. A port support post extends generally upwardly from a port side of the inner surface of the hull and provides a port deck supporting surface. A deck, which is constructed and arranged to support a rider in an operative riding position thereon, is mounted atop the hull with port and starboard supported portions of the deck engaging the port and starboard deck supporting surfaces, respectively, such that at least a portion of a weight of the rider is transferred to and borne by the deck supporting posts.

Abstract: The present invention permits the positioning and support of a fuel tank in a stable state while preventing unnecessary stresses from being generated in the fuel tank. A tapered, single projecting portion for positioning is formed on either the bottom portion of an inner wall of a hull or the bottom of the fuel tank. A tapered, single depressed portion for positioning is fitted on the projecting portion, and is formed on the opposing bottom portion of the fuel tank or the inner wall of the hull, respectively. A space is formed between a peripheral wall of the fuel tank and the inner wall of the hull that permits contraction and expansion of the fuel tank.

Abstract: An inner frame member, of a length that is less than the entire length of a hull, is joined to the inner surface of the hull that forms a lower portion of a body of a personal watercraft. The inner frame member has an engine mount portion that supports an engine thereon, an impeller shaft support region that supports thereon an impeller shaft of a propulsion device driven by the engine, and bulkheads extending in the lateral direction of the hull and joined to the inner surface of the hull. In accordance with the present invention, the personal watercraft is light weight, but also retains rigidity and assembling efficiency of the hull.

Abstract: A watercraft includes an internal combustion engine mounted such that its crankshaft extends vertically. A gearbox is arranged beneath the engine and includes engine mounts attached directly thereto for mounting the engine to a mounting surface within the engine compartment. Thus, the engine may be mounted compactly arranged in the rear of the watercraft, thus minimizing the overall length of the engine compartment. Additionally, the engine mounts allow the engine to be mounted conveniently within a watercraft in a vertical orientation. The gear box may also include at least a portion of an exhaust conduit extending therethrough. The gear box may be also utilized as a lubricant reservoir for a lubrication system of the engine. Additionally, the exhaust conduit passing through the gear box may include a cooling jacket, thus protecting oil in the gear box from the heat emitted from the exhaust conduit therein.

Abstract: A watercraft has a mid-deck storage compartment. The storage compartment is mounted between a forward portion of the seat and a control mast. The storage compartment inclines rearward and partially overhangs an access opening into an engine compartment that is disposed beneath the seat. A box that is detachably connected to a deck of the watercraft defines the compartment. A cup holder can be disposed within the compartment with storage areas being defined around the cup holder and any cup or can that might be secured by the cup holder. The compartment also expands laterally as it increases in depth.

Abstract: A personal watercraft has an improved ventilation system for an engine compartment. The ventilation system is disclosed in the context of both two-cycle and four-cycle engines. The system includes a plurality of ducts that are strategically positioned on the watercraft. One of the ducts extends through a sidewall of a pedestal that carries an operator seat. Another of the ducts extends through a bottom plate connecting the seat to the hull. The ducts are configured to create airflow across various engine and exhaust system components. For instance, a portion of an exhaust system is interposed between two ends of two separate ducts in one arrangement. In another arrangement, a duct draws or forces air past a portion of the exhaust system. The portion of the exhaust system can include a catalyst. The system also creates a flow of air across a cylinder head in one arrangement and a lubricant reservoir in another arrangement.

Abstract: An immobilization system for watercraft includes a transponder mounted within a lanyard clip and a communication device mounted to be in the vicinity of the trasponder when the lanyard member is engaged with the kill switch assembly. The transponder emits a security code which is received by the communication device and is compared to a predetermined authorized security code. If the transponder does not include the correct security code, the engine will not start or will be killed.

Abstract: A personal watercraft with an exhaust system including a first and second mufflers each disposed in opposite sides of the hull. A manifold pipe communicates the engine with the first muffler. A transfer pipe communicates the first muffler with the second muffler. An outlet pipe communicates the second muffler to the atmosphere at an exhaust point located at an opposite side of the hull. The outlet pipe has a raised portion between the second muffler and the exhaust point so that only rotation of the watercraft in a first rotational direction will cause entrant water in the outlet pipe to flow into the second muffler. The transfer pipe has a raised portion between the first and second mufflers so that only rotation of the watercraft in second rotational direction about the longitudinal axis opposite the first rotational direction will cause water that has flowed into the second muffler to flow into the first muffler.

Abstract: An improved fuel delivery and injection system for a small watercraft engine reduces the heat effects within an enclosed engine compartment upon various components of the engine and upon the fuel within the fuel system. The fuel system integrates a fuel pump within a fuel tank at a location which minimizes the effects of watercraft leaning. The inlet of the fuel pump desirably corresponds, in the lateral direction, with a position of an inlet to the jet pump unit. In this position, the pump is less likely to draw air as the watercraft maneuvers. The fuel lines also are arranged within the engine to minimize the effect of engine heat produced by the exhaust system on the fuel delivery lines. The arrangement of the fuel pump and fuel delivery lines consequently improves the consistency of the fuel/air ratio within the fuel charge produced by the engine as less air and vapor delivered to the fuel injectors.

Abstract: The invention provide an adjustable steering mechanism for a watercraft. The watercraft has a hull including a main body, an upper wall engaging the hull and cooperating therewith to defme an engine compartment for housing an engine. The engine has an output shaft arranged to drive a water propulsion device of the watercraft The upper wall has a top surface and a bottom surface. The bottom surface facing forwardly towards engine compartment. A first steering means extends through the upper wall and is in communication with a steering mechanism of the watercraft. The first steering means also coupled to a steering shaft and handle. The steering shaft and handle are journalled for rotation about a first axis with respect to a rotation member.

Abstract: A personal watercraft has an improved ventilation system for an engine compartment. The ventilation system is disclosed in the context of both two-cycle and four-cycle engines. The system includes a plurality of ducts that are strategically positioned on the watercraft. One of the ducts extends through a sidewall of a pedestal that carries an operator seat. Another of the ducts extends through a bottom plate connecting the seat to the hull. The ducts are configured to create airflow across various engine and exhaust system components. For instance, a portion of an exhaust system is interposed between two ends of two separate ducts in one arrangement. In another arrangement, a duct draws or forces air past a portion of the exhaust system. The portion of the exhaust system can include a catalyst. The system also creates a flow of air across a cylinder head in one arrangement and a lubricant reservoir in another arrangement.

Abstract: The benefits of a sporty and maneuverable personal watercraft and those of a larger sport boat, having the ability to accommodate a large number of riders, are combined into a single watercraft. The watercraft is equipped with a rear sundeck large enough for passengers to sun bathe while the watercraft is stationary. Disposed beneath the sundeck are storage compartments, each having a lip-less seal for preventing the ingress of water into the compartments. Additionally, the storage compartments are large enough to store a variety of items and accessories such as food, clothes, and first-aid materials. The watercraft is designed such that a relationship between the position of its center of gravity and the position of its center of buoyancy, prevents the watercraft from tipping over even when three of four adults of average size simultaneously board the watercraft from the same side.

Abstract: Provided is a hull shape of a personal watercraft which can enhance speed performance, and still more, can also reduce rolling of a body. A bulging face 12 is formed on an outside part of a rear portion of a hull bottom 20 having a substantially V-shaped cross section and protrudes downward from an outside front face 20a positioned in front of the outside part. The bulging face 12 includes a fore part 13 inclined downward in the rearward direction, and a rear part 14 positioned above a virtual face A extended rearwardly from the fore part 13.

Abstract: The four stroke internal engine having an air intake system connected to the cylinder head and operatively connected to the intake passageway. The air intake system includes an air intake manifold having symmetrical construction with a central air passageway extending between a first end and a second end. At least one passageway extends from the central air passageway to a free end, which is operatively coupled to the intake passageway. The air intake system is usable for both a supercharged and normally aspirated engines.

Abstract: A detachable firefighting attachment is provided for a personal watercraft having a discharge nozzle. The attachment includes a tubular body having a lower end and upper end. There is a firefighting nozzle mounted on the upper end of the body. A fitting at the lower end of the body is shaped to fit the discharge nozzle of the personal watercraft. Water discharged from the discharge nozzle passes through the conduit to the firefighting nozzle. A forward mount is connected to the body and includes a first component releasibly connectable to the personal watercraft. There may be a steering nozzle communicating with the body adjacent to the fitting. There may be a diverter within the body adjacent to the steering nozzle for diverting water from the personal watercraft through the steering nozzle.

Abstract: A braking system for a small jet propulsion surfboard can be manufactured at reduced costs. The braking system includes left and right sponsons retractably attached to a surfboard body. Left and right locking units fix the sponsons to the surfboard body. An unlocking unit unlocks the lock units in order to free the sponsons from the surfboard body. A traction rope ensures that the freed sponsons remain connected to the surfboard body. The freed sponsons are pulled by the traction rope to thereby apply braking force to the jet propulsion surfboard. In an alternative embodiment, a system with a water-reversing cup can replace the sponsons.

Abstract: An adjustable steering column for use with a personal watercraft. The adjustable steering column comprises a steering column base fixed to the watercraft, an upper steering column connected to the steering column base, the upper steering column being movable between a first position and second position, and an adjustment mechanism for moving the upper steering column between the first and second positions. Preferably, the adjustment mechanism includes a screw with a knob on one end and a ball joint on the other end. The adjustment screw is manually operable to pivot the upper steering column with respect to the steering column base.

Abstract: The present invention comprises an engine for a watercraft that includes a plurality of separate cylinder bodies. A stay is provided that is supported by at least two of the separate cylinder bodies. The stay supports a portion of the exhaust system. Because the load is shared by the two separate cylinder bodies, the weight of the supported portion of the exhaust system is shared by the two cylinder bodies to inhibit flexion or twisting of the cylinder bodies.

Abstract: An improved arrangement of a fuel injection system within a personal watercraft reduces the likelihood that certain sensitive components of the fuel injection system will contact water, regardless of the orientation in which the watercraft floats. Because of the sporty nature of personal watercraft, these boats often are inverted or laid on their sides. The fuel injectors of the fuel injection system are positioned within an engine compartment of the watercraft so as to remain above the water surface level with the watercraft in any orientation. In one mode, the fuel injectors also are positioned above the ends of air ducts through which air is introduced into the engine compartment. The fuel injectors are also shielded by protective covers. As a result, the occurrences of water contacting the fuel injectors is reduced.

Abstract: A propulsion unit assembly for a personal watercraft provides for the quick and easy alignment of a propulsion device of the assembly relative to the longitudinal axis of the watercraft when mounting the propulsion device on the hull of the watercraft. The mounting arrangement includes a mounting plate having stoppers which cooperate with bosses formed on the front wall of the tunnel of the watercraft to properly align the mounting plate before fixing the plate to the hull and mounting the propulsion device thereto. In addition, the disclosed propulsion unit assembly includes an integrally formed cooling water supply system which utilizes the existing high-capacity jet pump unit to provide pressurized cooling water for cooling of the engine and associated watercraft components.

Abstract: A watercraft includes a plastic hull and a plastic deck which are joined together in a vertical direction. An upwardly extending portion on a part of the deck defines a seat platform at its top side. A straddle type seat for a rider is installed upon the seat platform. A discrete layer of vibration damping material is attached to opposed side walls of the seat platform. A discrete layer of auxiliary vibration damping material is attached to opposed side plates of the hull. The discrete layers of vibration damping material and the auxiliary vibration damping material damp vibrations from a propulsion apparatus, which propels the watercraft through water, and thus increasing the rider's comfort.

Abstract: A shade for a personal watercraft includes a canopy and a canopy support frame. The shade is formed to provide a clearance such that a person thrown from the craft to either of its sides is not in danger of striking the canopy or its frame. The frame is easily broken down into small, easily transported components and is quickly assembled and mounted onto the craft. A breakaway strap holds the shade in position at the helm of the craft.

Abstract: A jet ski braking system is provided including a jet ski having a bottom surface and a top control console including a steering mechanism, a seat and a pair of laterally spaced wells for placing feet of a rider. Also included is at least one pedal hingably coupled to the jet ski within one of the wells adjacent to the steering mechanism thereof. At least one brake flap is hingably mounted to the bottom surface of the jet ski. A connector assembly is included for lowering the brake flap upon the depression of the pedal.

Abstract: A watercraft having a speed measuring system which provides for accurate and consistent measurement of watercraft speed throughout the operation of the watercraft, including during violent maneuvers and/or sharp turns. The speed measuring system includes a ride plate assembly for a personal watercraft comprising a sensor and a plate. The sensor generally includes a moveable element and a housing supporting at least a portion of the moveable element. The plate includes a longitudinally-extending channel with the channel extending along at least a portion of the length of the plate. The housing is connected to an aft portion of the plate with at least a portion of the rotatable element being positioned in line with the channel.

Abstract: Several embodiments of personal watercraft employing exhaust systems that incorporate not only a catalyst, but also an exhaust silencing device for silencing the sounds of the exhaust gases. The components are laid out in such a way that there will be minimum heat transfer from the exhaust gases to the engine compartment, and also so that there will be a cooling air flow across the exhaust system to further provide this result. In one embodiment, the silencing device is mounted transversely at the front of the engine, and in other embodiments it is disposed longitudinally to the rear of the engine. In all embodiments, the components are laid out to maintain good fore and aft and side to side balance.

Abstract: A bulkhead structure for a personal watercraft reduces the weight of the personal watercraft while maintaining the rigidity of an outer shell of a body by utilizing the inside space of the body. Alternatively, the structure can further enhance the rigidity of the outer shell of the body without increasing the weight. The hull and a deck are joined to form the outer shell of the body of the personal watercraft. A plate-shaped member spans substantially horizontally in a direction of the width of the body of the personal watercraft and has right and left sides fixed in the vicinity of a junction portion of the hull and the deck.

Abstract: A steering structure of a personal watercraft comprising, a mount member 3 provided on a mount base 2 on an upper portion of a deck 1, a hold member 8 provided inside of the deck separated downward from the mount members 3 by a predetermined distance, a handle support shaft 4 supported by the hold member 8 and the mount member 3, and a support collar 11 provided at the handle support shaft 4, for rotatably supporting the handle support shaft 4, and for absorbing a deviation of support positions of the handle support shaft 4.

Abstract: It is an object of the invention to provide a personal watercraft having a rear deck floor which can house goods necessary for water-skiing or the like and is provided with a space where a water-skier or the like sits when getting into the water or a space for embarkation when coming out of the water into a watercraft. In a personal watercraft having a whole plane view almost shell-shaped comprising a riding seat S provided from an almost central portion of a body A of a watercraft to a rear portion thereof, a steering handlebar 21 provided in front of the riding seat S, an engine E for propulsion provided below the riding seat S, and a jet pump P provided behind the engine, the jet pump being provided with an outlet port rearward for being driven by the engine, a rear deck floor 1 having a space for at least one adult to sit is provided behind the riding seat S and has an openable hatch cover 1A formed on the space, and a rear storage box 1B is formed under the hatch cover 1A.

Abstract: A four cycle power personal watercraft having an improved crankcase ventilating and induction system. The crankcase ventilating system ensures that the crankcase gases will be passed to the combustion chambers to eliminate unburned hydrocarbons from escaping to the atmosphere. However, the system is also designed so as to preclude separated lubricant from passing into the induction system and also to prevent water from entering the engine through the induction system or the ventilating system.