Abstract: An exhaust treatment device is provided for an internal combustion engine of a marine propulsion system. An outer chamber contains a first inner chamber within it and slidably supports the inner chamber. An exhaust inlet conduit directs a stream of exhaust gases from a cylinder of the internal combustion engine directly into the inner chamber. The inner and outer chambers are supported relative to each other to allow relative movement of these two components in response to changes in the differential temperature between the two components. A rail system slidably supports the inner chamber relative to the outer chamber. The exhaust treatment device comprises a liquid cooled housing surrounding the inner and outer chambers. Exhaust gas is directed through the inner chamber and then into the outer chamber at a closed end of the exhaust treatment device. Exhaust gases then flow through the outer chamber to an exhaust conduit of the marine propulsion system.

Abstract: An exhaust valve actuation system utilizes pressurized air provided by an air compressor and controlled by signals from a controller, such as an engine control module. The pressurized air is directed by a pressure valve that operates under the control of the controller and the exhaust valve is thus moved as a function of a preselected parameter monitored by the engine control module. The pressure valve can operate in a two position manner or a multi position manner, depending on the particular embodiment of the present invention utilized.

Abstract: A fuel injection system incorporates a plurality of fuel injection arrangements, wherein each fuel injection is associated with a particular cylinder of the engine. Each of the fuel injection arrangements comprises a fluid passageway in which fuel and air are combined prior to injection into a combustion chamber of the cylinder. A valve is moveable with respect to an injection port to allow the pressurized fuel/air mixture to flow from the fluid passageway into the combustion chamber. A fuel injector is used to inject liquid fuel into the fluid passageway to be combined with pressurized air within the passageway. The system has a common air rail and a common fuel rail which are each connected to a plurality of the fuel injection arrangements. Upward movement of a piston within a cylinder is used to pressurize the air within the common air rail. All of the fuel injection arrangements can be used to contribute pressurized air to the common air rail.

Abstract: An engine control scheme determines the appropriate and desired magnitude of scavenging air flow for a two stroke engine as a function of both load and engine speed. The desired air flow is determined, as a function of engine load and engine speed, to achieve an optimal magnitude of emissions within the exhaust stream and to also optimize a reverse thrust capabilities of the marine propulsion system.

Abstract: A cover for an outboard motor is provided to protect an operator from a flywheel. The cover is disposed under the cowl of the outboard motor. The cover is made of a generally rigid material, such as plastic, with first and second sheets being associated together to form conduits with openings extending therefrom. In one particular embodiment, one of the openings is shaped to receive an inlet of a compressor and this provides a positioning aid in attaching the cover to the engine. This device eliminates the need for flexible hoses and accomplishes two tasks with one component. It provides air conduits for the air passing through the cover and it provides a generally rigid means for locating the proper location of the cover.

Abstract: A cooling system for an internal combustion engine is provided with coolant paths through the cylinder block and cylinder head which are connected in serial fluid communication with each other. In parallel with the cooling path through the cylinder head, a first drain is connected in serial fluid communication with a pressure responsive valve and the path through the cylinder block. A temperature responsive valve 64 is connected in serial fluid communication with the cylinder head path and in parallel fluid communication with the first drain. A pump is provided to induce fluid flow through the first and second coolant conduits and the first and second drains, depending on the space of the pressure responsive valve and the temperature responsive valve.

Abstract: A direct fuel injected two-stroke engine controls spark ignition timing and/or ignition coil dwell time on a cylinder-specific basis. The engine also preferably controls fuel injection timing and amount and injection/delivery duration on a cylinder-specific basis. Cylinder-specific customization of spark ignition and fuel injection allows better coordination of spark with fuel injection which results in better running quality, lower emissions, etc. Memory in the electronic control unit for the engine preferably includes a high resolution global look-up table that determines global values for spark ignition and fuel injection control based on engine load (e.g. throttle position, manifold air pressure, etc.) and engine speed. Memory in the electronic control unit also includes a plurality of low resolution, cylinder-specific offset value look-up tables from which cylinder-specific offset values for spark ignition and fuel injection can be determined, preferably depending on engine load and engine speed.

Abstract: A two-stroke direct fuel injected internal combustion engine has an ignition coil dwell time control system. An electronic control unit controls switching of electronic ignition coil drivers in a manner to minimize ignition coil dwell times at medium and high engine speeds where low ignition coil dwell times can be used without sacrificing engine performance. The electronic control unit also implements an intermittent spark plug cleaning strategy to remove carbon deposits from fouled spark plugs. Intermittent cleaning is accomplished during engine operation by periodically raising the ignition coil dwell time to an exaggerated cleaning level for a relatively short period of time (e.g. one minute) after it is determined the spark plug cleaning should occur (e.g. 10 to 20 engine operating hours since previous cleaning).

Abstract: Oil flow from an air compressor is directed to a nozzle within or near the entrance of an intake manifold of an engine. Air is directed to the nozzle from a pressure regulator associated with the air compressor. The air is used to atomize the liquid lubricant and create a fine mist that is injected into the air intake manifold and evenly distribute the lubricant to the cylinders of the engine.

Abstract: An engine control system is provided with two sets of gain factors for use in conjunction with a PID control system. When a gear selection mechanism is in a steady state, a first set of gain factors is used so that the engine control system is less responsive and the engine operates more smoothly. When the gear selection mechanism is being moved from a neutral position to either forward or reverse gear or vice versa, a second set of gain factors are substituted for the first set so that the engine control system will be more responsive and the sudden change in the load on the engine will not cause a stall condition or a sudden increase in the RPM. This technique can typically be employed in a proportional, integral, and differential (PID) control system, but alternative control systems can also benefit from its use.

Abstract: A lubrication system for an internal combustion engine directs a dedicated flow of oil to the cylinder bores of an engine. In addition, a more traditional oil circuit is provided to lubricate the components within the crankcase of the engine. A 2-way valve is used to alternate the flow of oil from an oil pump through the two alternative circuits according to a duty cycle that is selected as a function of a pre-selected engine parameter. The engine parameter, in a typical application, is shaft speed or rpm. By directing oil to the cylinder bores at a higher duty cycle when the engine speeds are low, the pistons are adequately lubricated when, otherwise, the low engine speed could cause difficulty in providing a proper flow of lubricant to the cylinder bores.