Abstract: A marine propulsion system includes a marine drive having an electric motor powerhead, at least two marine batteries, each with a maximum operating voltage at or below 60 volts, and a switch box. The switch box is configured to be removably connected to the marine drive and to each of the at least two marine batteries so as to electrically connect each of the at least two marine batteries in parallel to power the marine drive.

Abstract: An intake plenum is for a marine engine, the marine engine having first and second throttle devices for controlling flow of intake air to the marine engine. The intake plenum has an airbox providing an expansion volume, first and second inlets that convey the intake air in parallel to the expansion volume, first and second outlets that convey the intake air in parallel from the expansion volume to the first and second throttle devices, and first and second Helmholtz-style attenuator devices located at the first and second outlets, respectively. Together the first and second inlets, expansion volume, and first and second Helmholtz-style attenuator devices are configured to attenuate different frequencies of sound emanating from the marine engine via the first and second outlets.

Abstract: An intake manifold is for a marine engine having a throttle for controlling flow of intake air to the marine engine. The intake manifold has a plenum for receiving the intake air from the throttle, a plurality of intake runners which extends from upstream ends for receiving the intake air from the plenum to downstream ends for discharging the intake air to the marine engine, and a quarter wave resonator extending from an open end coupled to the plenum to a closed end, the quarter wave resonator having a tuned elongated cavity configured to attenuate sound emanating from the marine engine via the plurality of intake runners.

Abstract: An intake plenum is for a marine engine, the marine engine having first and second throttle devices for controlling flow of intake air to the marine engine. The intake plenum has an airbox providing an expansion volume, first and second inlets that convey the intake air in parallel to the expansion volume, first and second outlets that convey the intake air in parallel from the expansion volume to the first and second throttle devices, and first and second Helmholtz-style attenuator devices located at the first and second outlets, respectively. Together the first and second inlets, expansion volume, and first and second Helmholtz-style attenuator devices are configured to attenuate different frequencies of sound emanating from the marine engine via the first and second outlets.

Abstract: A marine engine includes a cylinder block having first and second banks of cylinders disposed along a longitudinal axis and extending transversely relative to each other in a V-shape so as to define a valley there between, and first and second exhaust logs in which exhaust gas from the first and second banks of cylinders are collected and conveyed. An exhaust manifold is located in the V-shape and configured to merge said exhaust gases from the first and second exhaust logs and to convey said exhaust gases. The exhaust manifold has a first inlet port that receives substantially all said exhaust gas from the first exhaust log and a second exhaust inlet port that receives substantially all said exhaust gas from the second exhaust log. The first and second inlet ports are longitudinally offset relative to each other.

Abstract: A marine drive is for propelling a marine vessel. The marine drive includes: an engine; an exhaust manifold that conveys exhaust gas from the engine; a cooling jacket on the exhaust manifold, wherein a cooling passage is defined between the cooling jacket and the exhaust manifold; a cooling pump that pumps cooling fluid through the cooling passage so as to cool the exhaust manifold and the exhaust gas; a power steering actuator configured to steer the marine drive relative to the marine vessel; a power steering pump that pumps power steering fluid from a power steering reservoir to the power steering actuator; and a power steering cooler on the exhaust manifold and configured such that the power steering fluid is cooled by the cooling fluid in the cooling passage. In some examples the marine drive is configured for use in an outboard motor.

Abstract: An exhaust manifold is for an outboard motor having an internal combustion engine. The exhaust manifold has an exhaust conduit that conveys exhaust gas from the internal combustion, and a cooling jacket on the exhaust conduit. The cooling jacket defines a first cooling water passage that conveys cooling water in a first direction alongside the exhaust conduit, a second cooling water passage that conveys the cooling water from the first cooling water passage in an opposite, second direction alongside the exhaust conduit, and third cooling water passage that is separate from the first and second cooling water passages and conveys spent cooling water from the internal combustion engine to a thermostat.

Abstract: An exhaust system for a marine propulsion device having an engine and a driveshaft housing. An exhaust manifold having a downstream end with an outer surface conveys exhaust gas from the engine. An exhaust conduit having an upstream end with an outer surface conveys the exhaust gas to the driveshaft housing. A flexible coupler couples the downstream end of the exhaust manifold and the upstream end of the exhaust conduit, retaining a gap between them. A metallic coil is aligned with the flexible coupler, which biases the metallic coil into contact with the outer surfaces of the exhaust manifold and the exhaust conduit to conduct heat between them. First and second clamps engage outer surfaces of the flexible coupler to cause inner surfaces of the flexible coupler to sealingly engage the outer surface of the exhaust manifold, and the outer surface of the exhaust conduit, respectively.

Abstract: A marine propulsion device includes an internal combustion engine; an axially elongated exhaust conduit that conveys exhaust gas from the upstream internal combustion engine to a downstream outlet; a cooling water sprayer that is configured to spray a flow of cooling water radially outwardly toward an inner diameter of the axially elongated exhaust conduit; a temperature sensor located downstream of the cooling water sprayer and configured to sense temperature of the exhaust gas and cooling water; and a controller configured to identify a fault condition associated with the cooling water sprayer based on the temperature of the exhaust gas and cooling water.

Abstract: An internal combustion engine for an outboard motor comprises a cylinder block having first and second banks of cylinders that extend transversely with respect to each other in a V-shape so as to define a valley there between. An exhaust manifold conveys exhaust gas from the internal combustion engine and is at least partially disposed in the valley. A supporting mechanism supports the exhaust conduit with respect to the internal combustion engine. The supporting mechanism is configured to allow the exhaust conduit to move with respect to the internal combustion engine in 360 degrees in a plane defined by the lateral and transverse axes, and laterally towards and away from the internal combustion engine, thereby facilitating assembly of the exhaust manifold and the internal combustion engine despite positional tolerance differences there between.

Abstract: An outboard marine propulsion device comprises an internal combustion engine having a cylinder head and a cylinder block; and an exhaust manifold that discharges exhaust gases from the engine towards a vertically extending catalyst housing. The exhaust manifold has a plurality of horizontally extending inlet runners upwardly that receive the exhaust gases from the engine, and a vertically extending collecting passage that conveys the exhaust gases from the plurality of horizontally extending inlet runners to a bend that redirects the exhaust gases downwardly towards the catalyst housing.

Abstract: An outboard marine propulsion device comprises an internal combustion engine having a cylinder head and a cylinder block and an exhaust manifold that discharges exhaust gases from the engine towards a vertically elongated exhaust tube. The exhaust manifold has a plurality of inlet runners that receive the exhaust gases from the engine, and a vertically extending collecting passage that conveys the exhaust gases from the plurality of inlet runners upwardly to a bend that redirects the exhaust gases downwardly towards the exhaust tube. A cooling water jacket is on the exhaust manifold and conveys cooling water alongside the exhaust manifold. A catalyst housing is coupled to the exhaust manifold and a cooling water jacket is on the catalyst housing and carries cooling water alongside the catalyst housing. A catalyst is disposed in the catalyst housing.

Abstract: A rocker box assembly for a motorcycle engine having a cylinder head. The rocker box assembly includes a base, a cover, and a breather assembly. The base is configured to be coupled to the cylinder head. The cover is coupled to the base and cooperates with the base to at least partially define a rocker chamber and to at least partially define a breather assembly housing within the rocker chamber. The breather assembly is positioned within the breather assembly housing and is operable to vent a pressure pulse from within the engine.

Abstract: A rocker box assembly for a motorcycle engine having a cylinder head. The rocker box assembly includes a base, a cover, and a breather assembly. The base is configured to be coupled to the cylinder head. The cover is coupled to the base and cooperates with the base to it least partially define a rocker chamber and to at least partially define a breather assembly housing within the rocker chamber. The breather assembly is positioned within the breather assembly housing and is operable to vent a pressure pulse from within the engine.

Abstract: The present invention directed to a motorcycle that includes a frame, a steering fork, a triple clamp and a motorcycle accessory mounted to a bottom surface of the triple clamp. The triple clamp rotatably couples the motorcycle frame to a pair of fork tubes that are part of the steering fork such that the steering fork and triple clamp rotate with respect to the motorcycle frame. Mounting a motorcycle accessory to the bottom surface of the triple clamp locates the mounting hardware beneath the triple clamp such that the mounting hardware is hidden from casual viewing. Hidden mounting hardware increases the aesthetic appearance of a motorcycle.