Abstract: A number of embodiments of personal watercraft having catalytic exhaust systems for treating and purifying the exhaust gases. In all of the embodiments, the catalyst is positioned and disposed so as to be protected from water. In addition, arrangements are provided for cooling the catalyst, for circulating ventilating air across it, for isolating it from other components such as the fuel tank, and for permitting its flushing with fresh water after operating in a salt water environment.

Abstract: A small, personal watercraft powered by a four cycle internal combustion engine. The engine is provided with a dry sump lubrication system for permitting the engine to be mounted low in the hull and this dry sump lubrication system includes a lubricant tank mounted within the hull separately from, but spaced closely to, the engine. Induction and exhaust systems are provided for the engine which include position responsive valves that close when the watercraft is inverted to preclude water from entering the combustion chamber through either the intake or the exhaust system. The induction system also includes an air inlet device that has its own position responsive check valve and which provides a centrifugal separator for separating water from the air inducted into the engine.

Abstract: A corrosion-resistant high-strength drive connection between a coupling element and a shaft that is supported in an anti-friction bearing. The shaft has a direct splined connection with the coupling element and is encircled by a corrosion-resistant sleeve that has an inter-fitting relationship with the coupling element to protect the spline from corrosion.

Abstract: Two embodiments of exhaust systems for small watercraft that include cooling jackets circling a portion of the exhaust conduit. At least a portion of the water from the cooling jacket is mixed with the exhaust gases but at a point spaced substantially downstream of the cooling jacket so as to reduce the likelihood of water entering the engine through the exhaust system. In one embodiment, an additional cooling jacket is provided to which the coolant from the first cooling jacket is introduced and then discharged into the exhaust conduit. The second cooling jacket is disposed substantially downstream of the first cooling jacket.

Abstract: An arrangement and structure for running a marine engine for a brief period of time after the engine cooling jacket has been depleted of water so as to insure complete purging of water and water vapor from within the engine. In the illustrated embodiment, this operation is initiated by actuation of the starter switch and a timer is started to run only in the event the coolant is not in the engine for shutting of the engine after the lapse time has run.

Abstract: An engine assembly for powering a watercraft that has a front cover which contains a number of electrical components for the engine including the flywheel magneto of the engine, a CDI ignition system for firing the spark plugs and additional components. This permits ease of servicing and reduces the number and length of the interconnecting electrical conduits.

Abstract: Two embodiments of water jet propulsion units having an improved bearing arrangement for supporting the impeller shaft where it passes through the hull for connection to the engine. In each embodiment, a gravity feed oil system supplies lubricant to the bearing.

Abstract: A water jet propulsion unit in which water is drawn off of the jet propulsion unit through a tap for other purposes, such as pumping the bilge with a jet pump or delivering coolant to the engine. A filter element which can be easily serviced is positioned in the conduit for precluding small particles which could clog the conduit from entering the conduit.

Abstract: A small watercraft embodying an improved exhaust system that is substantially completely watercooled by a cooling jacket. The exhaust system includes an elastic joint that is also completely surrounded by the cooling jacket so as to insure adequate cooling under all running conditions. A damming arrangement is incorporated so as to insure that all of the exhaust portions being cooled will be completely encircled with cooling water even when low amounts of water are being circulated and a drain system is also provided so as to insure that the cooling jackets will be drained when the watercraft is removed from a body of water.

Abstract: A jet propulsion unit for a small watercraft that incorporates a mechanism for actuating the reverse thrust bucket through an intermediate lever so as to permit a flexible cable to be employed that lies closely above the jet propulsion unit. The actuating device is constructed so as to provide self-locking of the reverse thrust bucket in at least one of its positions. Various linkage arrangements for achieving the interrelationship are disclosed.

Abstract: A small watercraft embodying an improved exhaust system that is substantially completely watercooled by a cooling jacket. The exhaust system includes an elastic joint that is also completely surrounded by the cooling jacket so as to insure adequate cooling under all running conditions. A damming arrangement is incorporated so as to insure that all of the exhaust portions being cooled will be completely encircled with cooling water even when low amounts of water are being circulated and a drain system is also provided so as to insure that the cooling jackets will be drained when the watercraft is removed from a body of water.

Abstract: A compact self-contained trim and tilt unit for a marine outboard drive that can be nested between the supporting brackets of the outboard drive so that all components are protected and so that external piping is avoided.

Abstract: A combined manual and automatic steering for a watercraft wherein there is provided an automatic steering control and a manual steering control that is operative to override the automatic control upon manual operator actuation.

Abstract: A small watercraft having a number of embodiments of exhaust systems into which coolant from the engine are discharged and which insure that water cannot enter the exhaust ports in the event the watercraft becomes displaced. In all embodiments, a water accumulating volume surrounds the discharge end of the exhaust pipe within an expansion chamber for trapping water in the event the watercraft becomes displaced from its normal condition and for return of the water therefrom upon erection of the watercraft. In a number of embodiments, gravity operated normally open control valves are also provided for closing the end of the exhaust pipe in the event the watercraft becomes displaced from its normal upright condition so as to insure that water cannot enter the exhaust ports of the engine.

Abstract: A small watercraft embodying an improved exhaust system that is substantially completely watercooled by a cooling jacket. The exhaust system includes an elastic joint that is also completely surrounded by the cooling jacket so as to insure adequate cooling under all running conditions. A damming arrangement is incorporated so as to insure that all of the exhaust portions being cooled will be completely encircled with cooling water even when low amounts of water are being circulated and a drain system is also provided so as to insure that the cooling jackets will be drained when the watercraft is removed from a body of water.

Abstract: Several embodiments of jet propelled water vessels wherein the bull and jet propulsion unit cooperate to form an inlet opening so that the outer housing of the jet propulsion unit need not itself form the inlet. This facilitates servicing since the water inlet need not be removed along with the jet propulsion unit for servicing and minimizes the likelihood of damage to the inlet duct and support for the impeller shaft.

Abstract: A number of embodiments of the invention wherein bilge water is discharged by means of a venturi pump and the discharge is upwardly directed externally of the watercraft to provide a spray that will indicate the watercraft location.

Abstract: Two embodiments of improved jet drive units for watercraft wherein the jet drive impeller shaft is coupled to the engine drive shaft by a slip spline connection for facilitating removal of the jet drive unit for servicing without removal of the engine. In addition, an improved connection is provided between the impeller shaft and the impeller that dispenses for the need for splines and thus permits a smaller impeller hub and a greater efficiency jet drive unit.

Abstract: Several embodiment of small boats having improved exhaust systems for precluding the entry of water into the engine combustion chambers from the body of water in which the watercraft is operating. In each embodiment, the exhaust system includes a horizontally extending expansion chamber with an exhaust gas outlet whichis defined by a vertically extending tube in the expansion chamber so as to prevent the likelihood of water reentering the engines through the exhaust system. Several arrangements are disclosed for draining the water from the expansion chamber and the exhaust gases are discharged from the engine into the tunnel around the jet drive unit.

Abstract: A compact self-contained trim and tilt unit for a marine outboard drive that can be nested between the supporting brackets of the outboard drive so that all components are protected and so that external piping is avoided.