Yamaha Hatsudoki Kabushiki Kaisha

Yamaha Marine Kabushiki Kaisha

Akitaka Suzuki

Hitoshi Motose

Kazumasa Ito

Tetsuya Mashiko

Yasuhiko Henmi

Naoki Kinomoto

Shigeharu Mineo

Satoshi Koyano

Masaru Tamaki

Takaaki Madachi

A watercraft includes an engine output control device that can adjust the maximum output of the engine. The output device can be constructed of mechanical devices for adjusting the relationship between the movement of a throttle lever and a throttle valve, an electronic device for proportionally controlling the position of throttle valves in relation to the movement of the throttle lever, are other devices for controlling engine speeds in other ways.

Engine control device for water vehicle

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.

Exhaust and control for watercraft engine

An engine for a watercraft includes a cooling system having a coolant supply. The coolant supply supplies an engine coolant jacket with a flow of coolant that is controlled by a temperature dependent flow control valve. The coolant supply also supplies an exhaust conduit coolant jacket independently of the engine coolant jacket.

Marine engine

A number of embodiments of induction systems for watercraft that employ, in addition to the plenum chamber of the air inlet device for the induction system, a further plenum chamber of a predetermined volume that communicates with the induction system plenum chamber for providing silencing and/or tuning effects to improve induction efficiency and silencing. In addition there are disclosed compact intake devices that incorporate plenum chambers for this purpose.

Induction system for watercraft engine

Several embodiments of personal watercraft having very compact construction, in particularly embodying a compact propulsion system wherein the engine and a number of its accessories all define a very compact area. A balance shaft is driven by the engine crankshaft for reducing the transmission of vibrations to the watercraft riders.

Watercraft propulsion system

A watercraft includes a monitoring and control system to sense the operational state of a catalytic device and a cooling system used with an exhaust system of the watercraft. The monitoring and control system includes a collection port formed downstream of the catalytic device. During diagnostic testing of the engine and the catalytic device, a collection element is inserted into the collection port. A plug, however, normally closes the collection port during normal engine operation. A cover extends over the collection port and a substantial portion of the surrounding exhaust pipe. The cover, or at least a portion thereof, is readily removable so as to provide access to the collection port. The exhaust system also includes a water trap located downstream of the collection port. A foam core support member supports the water trap within a hull of the watercraft, with an insulator positioned between the support member and the water trap. The insulator, as well as the monitoring and control system, prevent damage to the support member, by isolating the support member from the heated water trap and by preventing the exhaust system from over heating.

Exhaust system and control for watercraft

An air supply conduit system for a watercraft having an air breathing internal combustion engine within the watercraft interior includes at least one air supply conduit extending from an outlet end located in the watercraft interior to an inlet end located outside the watercraft. A noise suppressing resonating chamber connected to the air supply conduit damps noise from the internal combustion engine from the outlet end of the conduit towards the inlet end thereof. The air supply conduit may be positioned within the watercraft to minimize entrapment of liquid within the conduit and the noise suppressing resonating chamber. An inlet fitting including a noise suppressor is located at the inlet end of the conduit.

Engine air supply conduit for watercraft

Several embodiments of personal watercraft having very compact construction, in particularly embodying a compact propulsion system wherein the engine and a number of its accessories all define a very compact area. This permits the center of gravity to be located at the desired location and maintain good balance for the watercraft regardless of the number of passengers who occupy it.

Propulsion system for personal watercraft

A personal watercraft catalytic exhaust system wherein an over-temperature sensor is provided that is effective to shut down the engine in the event the catalyst reaches a dangerous temperature. The engine, once shutdown, cannot be restarted until the temperature falls below a predetermined temperature which may be lower than the overheat temperature. In the process of stopping the engine, it is slowed down first so as to give the rider additional warning that the shutdown procedure will be initiated.

Watercraft engine control

A lubrication system for the internal combustion engine of a motorcycle that includes a pump that outputs a constant amount of fluid per cycle of operation and a delivery valve which selectively passes lubricant to the engine or returns lubricant back to the system to vary the amount of lubricant supplied by the lubricant pump. The system is designed so as to self purge air from the system by mounting the lubricant pump and the delivery valve in close proximity to each other and at a lower level than the lubricant storage tank. In addition, the engine is supplied with lubricant from the supply outlet through a conduit that terminates at a point higher than the supply outlet so as to preclude lubricant from draining into the engine when the engine is not running.

Growing community of inventors

Shizuoka, Japan

Akitaka Suzuki