Abstract: Systems and methods are for monitoring underwater impacts to marine propulsion devices. The systems can comprise a marine propulsion device that is trimmable up and down about a trim axis; a trim sensor that senses at least one of a current trim position of the marine propulsion device relative to the trim axis and a rate at which the marine propulsion device is trimmed relative to the trim axis; and a controller that is configured to compare the rate at which the marine propulsion device is trimmed relative to the trim axis to a stored threshold value to thereby determine whether an underwater impact to the marine propulsion device has occurred.

Abstract: Systems and methods are for monitoring underwater impacts to marine propulsion devices. The systems can comprise a marine propulsion device that is trimmable up and down about a trim axis; a trim sensor that senses at least one of a current trim position of the marine propulsion device relative to the trim axis and a rate at which the marine propulsion device is trimmed relative to the trim axis; and a controller that is configured to compare the rate at which the marine propulsion device is trimmed relative to the trim axis to a stored threshold value to thereby determine whether an underwater impact to the marine propulsion device has occurred.

Abstract: An isolation mounting system is provided for the purpose of supporting a throttle body structure which is completely supported by an elastomeric support, but is held in non-contact association with an air intake manifold in order to effectively isolate the throttle body structure from vibration. This isolation protects potentially delicate components contained within a component housing that is rigidly attached to the throttle body structure.

Abstract: An air supply system for a marine engine includes an air duct, or sound attenuator cavity, that receives air through a plurality of inlets and directs air to an outlet of the air duct disposed over a throttle body of an air intake manifold. An air filter assembly is shaped to be attached to a wall of the air duct with a filter medium portion extending into the cavity of the air duct and an outlet port or nipple, extending out of the air duct. A compressor is connected in fluid communication with the outlet port of the air filter assembly through the use of a flexible tube, such as a rubber hose, in order to provide filtered air to the compressor. The air filter assembly is easily removed for inspection and/or replacement and is located with its filter medium within the protective housing of the air duct.

Abstract: A strain relief assembly for an outboard motor for relieving strain on wires, cables, lines or the like which extend between the boat and the cowl assembly which encloses the power head of the outboard motor. The stain relief assembly is preferably disposed within an opening formed in one of the cowl sections, and comprises a two-piece member. The two-piece member includes a series of indentations which cooperate to clamp the wires, cables, lines or the like therebetween when screwed together. With the strain relief assembly fixed to the wall of the cowl section forming the opening, this acts to maintain the wires, cables or lines in position relative to the cowl section for relieving strain thereon during movement of the outboard motor. A fuel line strain relief assembly is also provided, comprising a stem fixed to the two-piece member. An external fuel line supplies fuel to the stem, which is communicated therethrough to an internal fuel line extending between the stem and the power head.

Abstract: An exhaust relief system for an outboard motor includes an exhaust chamber into which exhaust is discharged from the engine. A first passage in communication with the exhaust chamber provides contraction of the exhaust as the exhaust passes rearwardly, from which the exhaust is discharged into an expansion chamber which substantially surrounds the exhaust chamber. From the expansion chamber, the exhaust is routed through and contracted into a second passage in communication with the expansion chamber, after which it is discharged to atmosphere. The tortuous path provided by the exhaust relief system of the invention, along with the repeated expansion and contraction of the exhaust as it flows to atmosphere, provides a muffling effect at idle operation.

Abstract: A locking mechanism for a two piece cowling for a marine engine includes a latch that is pivotally mounted on the lower cowling piece and includes a handle disposed within a recess on the exterior of the lower cowling so that when the latch is in its locked position, the handle is contained by the recess and is flush with the cowling so as not to detract from the styling of the cowling and the longitudinal axis of the elongated handle is disposed parallel to forces acting on the lower unit of the engine so as to resist forces tending to move the handle to its release position.

Abstract: A two stage carburetor for introduction of an air-fuel mixture into the crankcase of a two-stroke marine engine includes a carburetor body that defines a pair of throttle bores, one of which has a reduced cross-sectional area. The throttle bores deliver an air-fuel mixture to separate and distinct reed blocks having comparable cross-sectional areas.

Abstract: A locking mechanism for a two piece cowling for a marine engine includes a latch that is pivotally mounted on the lower cowling piece and includes a handle disposed within a recess on the exterior of the lower cowling so that when the latch is in its locked position, the handle is contained by the recess and is flush with the cowling so as not to detract from the styling of the cowling.

Abstract: A cowl and air inlet assembly for a marine outboard engine has a first cowl half having an edge portion with a tongue extending from the edge and a second cowl half having an edge portion with a groove for receiving the tongue of the first cowl half when the two halves are joined. A bonding material is disposed along the joint formed by the tongue and groove to permanently join the two cowl halves.