Yamaha Hatsudoki Kabushiki Kaisha

Mitsuhisa Hirano

Hisato Yamada

Yasukazu Kojima

Noboru Kobayashi

Chihiro Matsumoto

Makoto Nagafusa

Hideki Kishi

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.

Propulsion unit assembly for personal watercraft

A personal watercraft sponson arrangement has sponsons that are configured so as to improve buoyancy and stability upon leaning. The sponsons are designed to be detachably affixed to the hull of the watercraft through the use of a coupling system.

Sponson for watercraft

A personal watercraft exhaust system, hull underplate, and speed sensor and sponson arrangement. The exhaust system for the engine provides a compact assembly that incorporates a pair of expansion chamber devices on opposite sides of the tunnel to provide a water-trap effect, effective silencing, and still clear storage compartments of the hull. The sponsons are configured so as to improve the buoyancy and provide stability upon leaning, and the underplate mounts a speed sensor to the rear of but below the jet propulsion unit discharge so as to provide a good speed signal and to protect the speed sensor.

Exhaust system, hull, and speed indicator for watercraft

A control mast assembly for a small watercraft formed primarily from a unitary plastic assembly comprised of a foamed core and a surrounding protective covering. In one embodiment, the core is foamed in place and in the other the protective covering is formed from a fiberglass reinforced resin laid up around the core. Upper and lower fittings formed from lightweight metal castings provide pivotal connections to the hull of the watercraft and the support for the control mechanism.

Steering pole for jet propulsion boat

A number of embodiments of towing and towed watercrafts with particular emphasis on the construction and operation of the towed watercraft. The towed watercraft is formed with a hull that is configured to accommodate the water flow from a jet propulsion unit driving the towing watercraft so as to reduce resistance and improve the flow resistance of the towed watercraft. The towed watercraft has its seat disposed below the seat of the towing watercraft so an operator on the towing watercraft will not have his rearward vision impaired. A wide variety of traction devices are disclosed, each having a rigid tow bar and an arrangement for precluding pivotal movement of the towed watercraft relative to the towing watercraft upon deceleration of the towing watercraft. Arrangements are also disclosed wherein an outboard motor may be positioned in a container of the towed watercraft for auxiliary power of the towed watercraft.

Growing community of inventors

Iwata, Japan

Mitsuhisa Hirano