Induction system for 4-cycle engine of small watercraft

A watercraft comprising a hull defining an engine compartment, an internal combustion engine disposed in the engine compartment, a propulsion device driven by the engine, the engine including an engine body defining at least one combustion chamber therein, an induction system configured to guide air into the combustion chamber for combustion therein, the induction system comprising at least one plenum chamber having an upper portion and a lower portion being engageable with each other, the lower portion including a removable wall, additionally comprising at least one spark plug connected to the engine body, the plenum chamber extending over the at least one spark plug, wherein the removable wall is disposed above the at least one spark plug.

A watercraft comprising a hull defining an engine compartment, an internal combustion engine disposed in the engine compartment, a propulsion device driven by the engine, the engine including an engine body defining at least one combustion chamber therein, an induction system configured to guide air into the combustion chamber for combustion therein, the induction system comprising at least one plenum chamber having an upper portion and a lower portion being engageable with each other, the lower portion including a removable wall, wherein the removable wall comprises at least one inlet configured to guide air from the engine compartment into a volume of space defined by the at least one plenum chamber.

A watercraft comprising a hull defining an engine compartment, an internal combustion engine disposed in the engine compartment, a propulsion device driven by the engine, the engine including an engine body defining at least one combustion chamber therein, an induction system configured to guide air into the combustion chamber for combustion therein, the induction system comprising at least one plenum chamber having an upper portion and a lower portion being engageable with each other, the lower portion including a removable wall, additionally comprising a filter supported by the removable wall.

A watercraft comprising a hull defining an engine compartment, an internal combustion engine disposed in the engine compartment, a propulsion device driven by the engine, the engine including an engine body defining at least one combustion chamber therein, an induction system configured to guide air into the combustion chamber for combustion therein, the induction system comprising at least one plenum chamber having an upper portion and a lower portion being engageable with each other, the lower portion including a removable wall, additionally comprising an inlet assembly configured to guide air into a volume of space defined within the plenum chamber, the inlet assembly including a duct extending into the volume of space, additionally comprising an outlet of the plenum chamber through which air flows out of the plenum chamber and towards the engine body, wherein the duct defines an outlet which faces away from the outlet of the plenum chamber, and wherein the outlet of the duct defines a high point proximate to the outlet of the plenum chamber and a low point distal from the outlet of the plenum chamber.

A watercraft comprising a hull defining an engine compartment, an internal combustion engine disposed in the engine compartment, a propulsion device driven by the engine, the engine including an engine body defining at least one combustion chamber therein, an induction system configured to guide air into the combustion chamber for combustion therein, the induction system comprising at least one plenum chamber having an upper portion and a lower portion being engageable with each other, the lower portion including a removable wall, additionally comprising an inlet assembly configured to guide air into a volume of space defined within the plenum chamber, the inlet assembly including a duct extending into the volume of space, additionally comprising an outlet of the plenum chamber through which air flows out of the plenum chamber and towards the engine body, wherein the duct defines an outlet which faces towards the outlet of the plenum chamber.

A watercraft comprising a hull defining in engine compartment, an internal combustion engine disposed in the engine compartment, a propulsion device driven by the engine, the engine having an engine body defining at least one combustion chamber therein, an exhaust system for guiding exhaust gases from the combustion chamber to the atmosphere, an induction system configured to guide air along an induction airflow path to the combustion chamber for combustion therein, the induction system comprising a filter having at least a water repellent element, the filter being disposed along the airflow path so as to remove at least a portion of water or water vapor contained in air flowing along the airflow path, and an air supply device configured to guide air from a portion of the induction system downstream from the filter into the exhaust system.

A watercraft comprising a hull defining, an engine supported by the hull, the engine including an engine body defining a combustion chamber, an air induction system configured to guide air to the engine body, the air induction system comprising a plenum chamber, a throttle body, and an air filter, the plenum chamber having an air inlet port, the air filter positioned between the air inlet port and the throttle body along an air flow path through the induction system, the filter comprising at least a first filter element upstream from a second filter element, wherein the first filter element has a greater water-repellent property than that of the second filter clement and the second filter element has a greater oil-resistant property than that of the first filter element.