Abstract: An oil lubrication system for a marine outboard motor including an internal combustion engine. The oil lubrication system includes a series of oil passageways within the cylinder block of the internal combustion engine. The oil passageways are configured such that each cylinder in the internal combustion engine is supplied by its own oil passageway. Each of the oil passageways terminate in an outlet opening. The outlet opening is positioned within the cylinder block such that oil exiting the outlet opening is directed by the force of gravity into contact with a moving component of the internal combustion engine. As the internal components of the internal combustion engine move, oil contacting the components is physically distributed into contact with the bearings.

Abstract: A four cycle outboard motor that have water cooled engines and an oil pan that is formed in the upper portion of the drive shaft housing. An exhaust pipe collects exhaust gases from an exhaust guide and delivers to a cavity that is formed in the oil pan by an interior wall thereof. The exhaust pipe does not terminate below the lower surface of the oil pan and idle exhaust gases are delivered to the area between the exterior of the exhaust pipe and the interior surface of the oil pan that defines the cavity. These idle exhaust gases are discharged to the atmosphere through and above the water exhaust gas discharge. The oil pan lower surface has a drain opening that is aligned with a vertical drain opening in the drive shaft housing.

Abstract: A four-stroke cycle internal combustion engine, having a crankcase. A connecting rod is provided in the crankcase. An inner wall extends to surround all sides and the bottom of the connecting rod. An outer wall extends to surround the inner wall. The upper ends of the outer wall are connected to the inner wall to form an oil reservoir under the crankcase and oil recess areas on both sides of the crankcase therebetween. An oil dipper for splattering the oil contained in the oil reservoir is provided at the big end of the connecting rod. A slit is formed at a bottom of the inner wall for allowing the oil dipper to go though to make contact with the oil.

Abstract: An outboard motor having a multi-cylinder four-cycle, internal combustion engine as a power plant. The engine is provided with an oil reservoir in the upper portion of the drive shaft housing and lower unit. Oil is drained back to this oil reservoir by separate drain passages formed in the cylinder head and in the crankcase. In addition, an improved crankcase ventilating system is provided wherein the crankcase ventilating gases follow a circuitous path through the crankcase chamber, camshaft chambers and then to the intake system so as to reduce the emissions of hydrocarbons.

Abstract: A crankshaft bearing support arrangement is disclosed for an engine arranged such that the crankshaft is vertically oriented. The crankshaft rotates within a crankcase chamber defined by the cylinder block and a crankcase cover connected thereto. First web members which support half-bearings extend from the cylinder block. Mating half-bearings are supported by second web members position opposite the first web members. An oil flow passage is defined through the crankcase chamber generally opposite the cylinder block from a top end to a bottom end of the chamber. In one arrangement, the oil flow passage comprises individual passages through the second web members. In another arrangement, the oil flow passage comprises a space between an end of the second web members opposite the cylinder block and the crankcase cover.

Abstract: A lubrication system for an internal combustion engine provides drain openings at locations within individual crankcase portions where residual oil collects during normal operation. The drain openings are connected to orifices formed through cylinder walls of other crankcase portions of the engine. Conduits connect preselected drain openings to associated orifice check valves to pump the residual oil from the collecting regions to the cylinder walls of other crankcase portions using differential pressures that occur naturally between the associated crankcase portions. The drain openings located at the collecting regions can be located directly under primary oil entry points of the crankcase portions, but this relationship is not absolutely necessary as long as the drain openings are placed at the collecting regions or, alternatively stated, as long as the drain openings are placed at locations where oil will tend to flow from the points of primary oil entry into the crankcase portions.

Abstract: An improved and simplified outboard motor construction wherein the cooling and exhaust systems for the engine are formed with a minimum number of components and sealing joints. The exhaust system includes an elongated expansion chamber formed in the drive shaft housing. In addition, the drive shaft housing has a cylindrical section that is journaled within a swivel bracket for its steering movement. The volume between the external portion of the drive shaft housing and the internal portion of the swivel bracket forms a second expansion chamber that is employed for the low speed above the water exhaust gas discharge. The flow of cooling the water to and from the engine is controlled so that the exhaust gas interchange area between the power head and the drive shaft housing will be well cooled, as will the oil reservoir for the engine and the oil returned to it.

Abstract: An internal combustion engine is provided with fluid passages between adjacent cylinders. The fluid passages extend through walls that separate adjacent cylinders and are located axially within the cylinders at positions which advantageously define the periods when the fluid passages are blocked and unblocked by pistons moving within lower cylinders. Pressure differentials between adjacent crankcases cause pooled liquid lubricant to be pumped downward through the fluid passages and placed in liquid communication with the walls of the lower cylinder. This pumping action removes pooled lubricant from the transfer passages of one cylinder and causes the liquid lubricant to flow along the walls of a lower cylinder.

Abstract: An ignition arrangement for an internal combustion engine having an output shaft supported for rotation about an axis. The engine includes an engine housing at least partially enclosing the output shaft. Oil seals at least partially surround the output shaft for sealing the output shaft to the engine housing. An oil seal housing at least partially surrounds the output shaft and at least partially engages the oil seals. The oil seal housing directly supports a first ignition component.

Abstract: An oil pump for a lubricating system of an outboard motor is disclosed. The motor has a cowling defining an engine compartment, a water propulsion device, and a guide member having an upper surface and a lower surface, the guide member positioned in the cowling and generally dividing the engine compartment into an upper part and a lower part. An engine is positioned in the upper part of the engine compartment within the cowling and has an output shaft arranged to drive the water propulsion device. The lubricating system includes an oil pan positioned below the guide member and an oil passage leading from the pan through the guide member. The oil pump is positioned in the upper part of the engine compartment, but below the engine, and is driven by a lower end of the output shaft of the engine which extends below the engine, the oil pump having an oil inlet in communication with the oil passage through the guide member.

Abstract: A lubricating system for an internal combustion engine is provided wherein oil flows from a compressor oil drain port to a region of the engine which is to be lubricated. The source of lubricating fluid, such as the compressor, is transmitted through a first conduit between the compressor and a lubricant supply region of the engine block. The lubricant supply region is located between a first seal region, or labyrinth seal, and a region to be lubricated which can be a center main bearing. The region to be lubricated is located between the lubricant supply region and a first lower pressure region of the engine, such as the crankcase region associated with one of the cylinders of the engine. A check valve is used to resist flow of the lubricating fluid in a direction from the lubricant supply region to the lubricating fluid source.

Abstract: A single cylinder, internal combustion engine with an engine housing in which the overhead camshaft and crankshaft are rotatably supported. The housing includes an integrally formed cylinder and head. A timing belt disposed externally of the engine housing interconnects the crankshaft and camshaft, and a piston connected to the crankshaft reciprocates within an internal bore provided in the engine housing cylinder. The cylinder wall around the internal bore is of a generally uniform thickness and circumscribed by cooling fins such that the cylinder resists bore distortion during operation. The inventive engine further provides for the mounting of flywheels within the crankcase cavity in conjunction with an external, lightweight fan for engine housing cooling, as well as employs a cast in valve seat for the overhead valve assemblies.

Abstract: An arrangement for an engine positioned in a cowling of an outboard motor and having an output shaft arranged to drive a water propulsion device of the motor is disclosed. The engine has a first end and a second end and a centerline passing through the ends, at least one combustion chamber, an intake system positioned along a first side of the engine for delivering air to the combustion chamber, a lubricating system including an oil filter for delivering lubricant to the engine and an ignition system including an ignition coil for charging an ignition element corresponding to the combustion chamber. The ignition coil and oil filter are positioned along a second side of the engine opposite the intake system and arranged to reduce the transfer of heat from the filter to the coil, with the oil filter having an outermost portion which is positioned outwardly of the engine between the centerline and a second line which extends parallel to the centerline and passes through an outermost portion of the ignition coil.

Abstract: A single cylinder, internal combustion engine with a dry sump lubrication system. The engine includes an engine housing in which the overhead camshaft and crankshaft are rotatably supported, and the housing includes an integrally formed cylinder and head. A timing belt disposed externally of the engine housing interconnects the crankshaft and camshaft, and a piston connected to the crankshaft reciprocates within an internal bore provided in the engine housing cylinder. The cylinder wall around the internal bore is of a generally uniform thickness and circumscribed by cooling fins such that the cylinder resists bore distortion during operation. Dry sump lubrication is obtained by an external oil reservoir connected to a pump which supplies pressurized oil to the bearing journals of the camshaft. A portion of the oil at the camshaft bearing journals flows through passages provided within the cylinder to lubricate the bearing journals of the crankshaft.

Abstract: A vertical internal combustion engine in which lubricating oil can be cooled efficiently is provided. The engine includes a crankshaft directed in a vertical direction, a lubricating oil pump, an oil filter and a cooling water pump. A lubricating oil passage is arranged along a side wall of a main body of the engine and extends between the lubricating oil pump and the oil filter, a cooling water chamber is formed around the lubricating oil passage, and a branch water passage communicating with the cooling water chamber branches at a discharge side of the cooling water pump from a cooling water passage leading into the main body of the engine.

Abstract: An outboard motor body case supported on a swivel shaft through a connecting member. The swivel shaft is vertically swingable about a tilting shaft. An engine is mounted at an upper portion of the outboard motor body case, with a crankshaft thereof being oriented vertically, and a flywheel is mounted at a lower end of the crankshaft and disposed between an engine block and the connecting member. A dynamo is mounted within the flywheel, and a starter motor is engaged with a ring gear which is formed around an outer periphery of the flywheel. Thus, since the flywheel having a large weight is mounted at the lower end of the crankshaft, the position of the center of gravity of the outboard motor is lowered. Therefore, it is possible to easily perform a tilting-up about the tilting shaft with a small force. Moreover, since the flywheel is mounted on a power taking-off side of the crankshaft, the torsional vibration of the crankshaft can be reduced.

Abstract: A cylinder head is coupled to a cylinder block/cylinder head coupling surface of a cylinder block by ten bolts which are disposed to surround outer peripheries of cylinders. In order to enhance sealability of an opening of an oil passage defined radially outside the bolts as viewed from the cylinders, the cylinder block and the cylinder head are further fastened to each other by two bolts disposed in the vicinity of the opening. Thus, the fastening force of the cylinder block/cylinder head coupling surface can be increased to increase the degree of freedom in design of the opening of the oil passage defined in the coupling surface.

Abstract: An oil reservoir chamber, a crank chamber and a valve-operating chamber are provided in an engine body. The oil reservoir chamber and the crank chamber are in communication with each other through a through-hole, and the crank chamber and the valve-operating chamber are in communication with the each other through a one-way valve which is opened upon rising of the pressure in the crank chamber. The valve-operating chamber and the oil reservoir chamber are in communication with each other through an orifice. By utilizing a pressure pulsation in the crank chamber, an oil mist produced in the oil reservoir chamber is circulated from the oil reservoir chamber to the crank chamber, the valve-operating chamber and the oil reservoir chamber. Thus, in any operational attitude of an engine, the lubricating oil can be circulated without use of special oil pump.

Abstract: The present invention is an improved oil reservoir for an outboard motor. The oil reservoir is defined by an oil pan portion of an exhaust guide. The exhaust guide includes a support portion which is positioned below an engine powering the motor. The oil pan portion extends downwardly from the support portion. An opening provided in the support portion of the exhaust guide leads to the oil reservoir, serving as an oil return. Preferably, a gasket positioned between the exhaust guide and the engine partially obscures the opening, preventing backflow of oil from the reservoir into the engine when the motor is titled.

Abstract: In a working 4-cycle engine including a crankcase, a cylinder block inclined with respect to the crankcase, and an oil pan located in a lower portion of the crankcase. An auxiliary oil tank is disposed below the cylinder block in the direction of inclination of the cylinder block. The auxiliary oil tank communicates with the inside of the oil pan and normally assumes a position higher than the level of oil stored in the oil pan. However, when the engine is tilted down in the direction of inclination of the cylinder block, the oil stored in the oil pan flows into and is accumulated in the auxiliary oil tank. Thus, even if the engine is tilted down in the direction of inclination of the cylinder block, the oil stored in the oil pan is prevented from flowing into the cylinder.

Abstract: An overhead cam internal combustion engine having a slanted head design which permits the camshaft assembly comprising a camshaft, rocker arms and valve assemblies to be pre-assembled to the head and valve lash to be set off of the main engine assembly line. The slanted head design allows the chain sprocket and timing chain for driving the camshaft to be installed thereon after the head has been assembled to the engine block, accommodating the easy installation of the timing chain. L-shaped rocker arms, mounted on a single shaft, follow a single lobe overhead camshaft. Each rocker arm actuates a valve located on the side of the camshaft opposite that which it follows.

Abstract: A fluid reservoir for providing a supply of a lubricating fluid for an internal combustion engine, specifically for use in marine environments. The reservoir includes a housing for containing and protecting, a ventless flexible liner for housing a supply of fluid, where the flexible liner is located within the housing, and an orifice and conduit that extends through the ventless flexible liner and the housing for permitting the introduction of fluid into the ventless flexible liner and for permitting the removal of fluid therefrom. The fluid reservoir is constructed and arranged such that the ventless flexible liner is in a generally collapsed state until a fluid is introduced therein through the orifice. The introduction of fluid into the ventless flexible liner through the orifice expands the ventless flexible liner, while the removal of fluid from the ventless flexible liner collapses the ventless flexible liner proportionally as the fluid is removed and delivered to the engine.

Abstract: An outboard motor comprises an engine of vertical type in which a crank shaft is disposed vertically in an installed state of the engine, an engine holder supporting the engine, an oil pan which is disposed below the engine through the engine holder and in which an oil is accumulated, and a lubricating device for lubricating the oil from the oil pan to an inside of the engine. The lubricating device comprises an oil pump mounted to a lower side portion of the engine holder and adapted to suck the oil accumulated in the oil pan, an oil suction passage and an oil discharge passage. The oil suction passage and oil discharge passage extend in parallel to each other from the oil pump and are formed integrally with an inside portion of the engine holder.

Abstract: An oil reservoir chamber 22 in an engine E is formed into a tubular shape having annular corner portions 22a and 22b at opposite ends, and an oil slinger 25 is secured to a crankshaft 13 and has two splashing blades 25a and 25b with their tip ends being in proximity to the corner portions 22a and 22b, so that a lubricating oil in the oil reservoir chamber 22 is splashed by at least one of the two splashing blades 25a and 25b during rotation of the oil slinger 25 with any operative position of the engine E. Thus, a lubricating oil mist can be produced with any operative position of the engine E by the oil slinger of a simple structure including the two blades.

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.

Abstract: An outboard motor having an upper unit containing an internal combustion engine and a lower unit containing an exhaust guide is disclosed. The engine has a vertically oriented crankshaft having an end extending from the bottom end of the engine. A flywheel is positioned on the crankshaft at the bottom end of the engine within a recess defined by the exhaust guide. A starter motor is positioned at the bottom end of the engine and is positioned at least partially within the exhaust guide, the motor having a gear for engaging the flywheel to start the engine.

Abstract: An outboard motor having a high-performance V-type twin overhead cam four-cycle internal combustion engine. The oil reservoir for the engine is disposed in a driveshaft housing below the engine and an oil pump is driven off the lower end of the engine crankshaft for circulating the oil from the oil tank to the engine. The oil supply system for the engine includes a vertically extending main gallery and a drain passage which extend in parallel side-by-side relationship and which are disposed over the oil tank for ease of oil return. The exhaust and cooling system for the engine is configured so as to minimize heat transfer between the exhaust system and the lubricating system and to maintain a compact assembly.

Abstract: A four-cycle outboard motor having an oil tank that is disposed at least in part in the drive shaft housing of the outboard motor and an oil pump that is driven off of the lower end of the crankshaft. At least a portion of the conduits for transmitting oil from the oil tank to the oil pump and from the oil pump to the engine for its lubrication being formed integrally in a lower face of the cylinder block.

Abstract: An internal combustion engine that includes an induction system and oil filter that are disposed, at least in part, on the same side of the cylinder block. The induction system is configured so as to clear the oil filter so as to facilitate its servicing.

Abstract: A single cylinder, internal combustion engine with a dry sump lubrication system. The engine includes an engine housing in which the overhead camshaft and crankshaft are rotatably supported, and the housing includes an integrally formed cylinder and head. A timing belt disposed externally of the engine housing interconnects the crankshaft and camshaft, and a piston connected to the crankshaft reciprocates within an internal bore provided in the engine housing cylinder. The cylinder wall around the internal bore is of a generally uniform thickness and circumscribed by cooling fins such that the cylinder resists bore distortion during operation. Dry sump lubrication is obtained by an external oil reservoir connected to a pump which supplies pressurized oil to the bearing journals of the camshaft. A portion of the oil at the camshaft bearing journals flows through passages provided within the cylinder to lubricate the bearing journals of the crankshaft.

Abstract: A cylinder block of a vertically oriented multicylinder engine includes a cylinder block structure which is configured to support a crankshaft in a vertical orientation. The cylinder block includes a cylinder head mounting surface thereupon, and a plurality of cylinders therein. The plurality of cylinders are configured along horizontal axes. A reinforcing rib or wall is included, with an inclined surface which is inclined with respect to the axes of the cylinders, to ensure that oil which may contact the reinforcing rib flows downward into the crankcase of the engine.

Abstract: A crankcase compression four-cycle internal combustion engine having a valve actuating mechanism that is lubricated by first four-cycle type lubricating system. A second two-cycle lubricating system is provided for lubricating the crankcase and components associated therewith. The second lubricating system also delivers lubricant to the piston and piston pin through a groove passage way formed in part in the connecting rod for their lubrication.

Abstract: A number of embodiments of high pressure pumps for internal combustion engines having vertically extending output shafts. In each embodiment, the high pressure pump has its pump driving shaft rotatable about an axis that is parallel to the crankshaft axis and is driven by the crankshaft. This arrangement lends itself to application in outboard motors. The high pressure pump includes an integral lubricating pump for lubricating components of the high pressure pump.

Abstract: A four-cycle outboard motor embodying an improved lubricating system. The lubricating system drains oil from the cylinder head back to the oil tank, in a manner so as to not add to the length of the engine. In addition, an improved crankcase ventilating system is employed that incorporates a simple baffle arrangement for ensuring that oil thrown by the crankshaft rotation will not pass through the ventilating passage into the cylinder head or escape from the ventilating system.

Abstract: In a vertical engine having a crankshaft directed in a vertical direction and a flywheel provided on a lower end of the crankshaft projected through a bottom wall of a crank chamber, the crank chamber is formed by a skirt section integral with a cylinder block and a split crankcase attached to the skirt section putting respective contacting faces together and an oil dropping hole is formed in a bearing wall section provided on the cylinder block side and forming a lowest crank bearing section within the crank chamber. The oil dropping hole communicates with an lower side of the bearing wall section and an upper side of the bearing wall section positioned within a lowest cylinder and is inclined downward from the cylinder side to the contacting face of the skirt section facing to the split crankcase. A flywheel space is formed under the bottom wall of the crank chamber and an oil pan is provided under the flywheel space.

Abstract: Bulk and complexity of a lubrication system incorporated in an internal combustion engine (10) having an engine block (11), a power shaft (12) mounted in the engine block for rotation about a power shaft axis, a combustion chamber (18), a valve arrangement (20) for controlling intake to and exhaust from the combustion chamber (18), a cam device (22) for actuating the valve arrangement (20), and a pressurized oil lubrication system (15) is avoided in a construction wherein the cam device (22) and the pressurized oil lubrication system (15) include a ring cam (24) journalled on the block (11). The ring cam (24) has an outer cam-shaped periphery (26) for actuating the valve arrangement (20), and an inner periphery (35) configured as a ring gear (36).

Abstract: A fluid reservoir assembly for providing a supply of a lubricating fluid for an internal combustion engine, specifically for use in marine environments. The assembly includes an outer shell for containing and protecting the assembly, a ventless flexible liner for housing a supply of lubricating fluid, where the flexible liner is located within the outer shell, and an orifice and conduit that extends through the ventless flexible liner and the shell for permitting the introduction of lubricating fluid into the ventless flexible liner and for permitting the removal of lubricating fluid therefrom. The fluid reservoir assembly is constructed and arranged such that the ventless flexible liner is in a generally collapsed state until a lubricating fluid is introduced therein through the orifice.

Abstract: A fuel system for an outboard motor includes a low-pressure fuel transport subsystem and a high-pressure fuel delivery system. The fuel transport system guides fuel from a fuel tank located in the hull of the watercraft to a fuel tank located with a cowling surrounding the engine. The high-pressure fuel delivery system supplies fuel to a fuel rail that communicates with fuel injectors of the engine's induction system. The induction system communicates with crankcase chambers on a side of the engine opposite of the engine cylinders. The low-pressure fuel transport subsystem is located on a side of the induction system opposite of the high-pressure fuel delivery subsystem. This layout minimizes the flow path length from the fuel tank within the cowling to the fuel rail. It also reduces the girth of the engine and simplifies the arrangement of the fuel hoses of the fuel supply system.

Abstract: A lubricating and drive system for a marine propulsion transmission that is comprised of an upper reversing transmission and a lower final drive transmission. A lubricant pump is driven off an input shaft to the reversing transmission for supplying lubricant for actuating its clutches and also for lubricating its gears. The pickup for the lubricant pump is disposed at a lower position in the final drive gear case so as to maintain a low lubricant level therein when the unit is operating so as to reduce drag.

Abstract: A removable oil tank and oil filter for four cycle dry sump internal combustion engines having particular utility in marine applications. A support for the tank is attached to or near the engine and the oil tank is held in engagement with the support by mechanical quick disconnect retainers. Oil lines connecting the tank and the engine oil circulating system are connected by quick disconnect fluid connectors. One portion of the quick disconnect fluid connectors may be fixedly attached to a support for the tank in a position where they help support the oil tank when the connectors are joined.

Abstract: A lubricant supply system for a two-stroke internal combustion engine, which system includes first and second adjacently located and substantially sealed crankcase chambers which alternately experience high and low pressure conditions which are out of phase with respect to the occurrence thereof, first and second oil supply passages respectively communicating with the first and second crankcase chambers, an oil supply circuit including an oil supply chamber adapted to contain oil and having therein a formation including therein a recess isolated from the oil supply chamber and communicating with the first and second oil supply passages, a metering rod including therein an indentation and supported in the oil supply chamber for movement in the formation between a first position wherein the indentation is located in the oil chamber, thereby affording filling of the indentation with oil, and a second position wherein the indentation is located in the formation in communication with the recess, thereby affording

Abstract: An upper intake pipe and a lower intake pipe interconnecting a left bank and a throttle body are disposed along a left side of a V-shaped multi-cylinder engine having a vertically placed crankshaft. The lower intake pipe is disposed by utilizing a waste space which is defined between a starter motor and an oil filter, while the oil filter is disposed by utilizing a waste space which is defined between the upper and lower intake pipes. Thus, it is possible to rationally dispose the intake pipes and other auxiliaries on a side of an engine block to reduce the size of the engine for the outboard engine system.

Abstract: An outboard engine assembly for use on a boat includes an engine having a substantially vertical crankshaft and a pair of banks of vertically juxtaposed horizontal cylinders, the banks being arranged in a V shape, the cylinders of the banks having axes angularly spaced from each other by an angle of 90.degree. or smaller. The outboard engine assembly has a propeller operatively connected to a downwardly extending vertical shaft coupled to the crankshaft. The engine and the vertical shaft is accommodated in a case assembly. The engine and the case assembly are installed on the hull of the boat by upper and lower support members. Vibroisolating rubber dampers are disposed between the boat hull and the upper and lower support members for isolating vibrations from the engine from the boat hull.

Abstract: An internal combustion engine comprises a vertical crankshaft rotatable in a crankcase, a piston reciprocable along a cylinder axis, and a push rod tube. The push rod tube communicates between the crankcase and a rocker box, and is positioned below the cylinder axis and upwardly inclined with respect to the cylinder axis. A cam gear agitates oil in the crankcase so that the oil is conveyed through the push rod tube into the rocker box and returns through the push rod tube to the crankcase under the force of gravity. In another embodiment, the engine comprises a crankshaft having an arcuate throw and a crankpin. A connecting rod has a continuously formed big end installable over the arcuate throw to cooperate with the crankpin. A flywheel is mounted to the crankshaft on a side of the crank pin opposite a balancing web, and has a radially offset center of gravity to balance forces applied to the crankshaft through the connecting rod by the piston.

Abstract: A gear 11 on a crankshaft 10 is made to engage with an internal gear 21 having twice the number of teeth of the gear 11, cams 22 are formed on the exterior surface of the internal gear 21, and the cams 22 are connected with valve actuating mechanisms 40 for actuating an exhaust valve 44 and an intake valve 40 to open or close. The gear 11, the internal gear 21, etc. have the function of an oil pump.

Abstract: An engine unit in which a crank shaft is arranged perpendicularly in its housing in the state of use thereof comprises a housing defining a crank chamber therein, a crank shaft disposed in the crank chamber to be rotatable, a piston-cylinder assembly disposed in the housing, a valve mechanism operatively connected to the piston-cylinder assembly for sucking and discharging air in the cylinder, and a valve moving mechanism for driving the valve mechanism so as to open or close the same. The valve moving mechanism includes a push-rod members, a push-rod cover member covering the push-rod members with a space therebetween. A rocker chamber is disposed in the housing and communicated with the space, and a drain pipe is disposed between a lower portion of the rocker chamber and a lower portion of the crank chamber so as to establish communication therebetween with an inclination in the state of use.

Abstract: A plurality of cylinders are defined in a single cylinder block, and a single cylinder head common to the cylinders is mounted on the cylinder block. Exhaust passages are provided in the cylinder head at a location corresponding to an inner side and central portion of a V-shape formed by the cylinders, the exhaust passages communicating with the cylinders, respectively. Intake passages are provided in the cylinder head at a location corresponding to opposite outside positions of the V-shape, the intake passages communicating with the cylinders, respectively. The intake passages open into a side of the cylinder head on opposite sides of the V-shape, and fuel injection nozzles provided in the intake passages, respectively. The exhaust passage extend parallel to a crankshaft within the cylinder head and open into the corresponding side of the cylinder head. A water jacket is defined around the exhaust passages to surround the exhaust passages.

Abstract: Disclosed herein is a cylinder head comprising a one-piece casting including a cylinder block mounting surface adapted to mate with a mounting surface on a cylinder block and including vertically spaced first and second recesses adapted to respectively form portions of first and second combustion chambers and respectively including first and second exhaust ports, a bottom surface extending transversely to the cylinder block mounting surface and including an exhaust gas outlet, and an internal exhaust gas passage extending between the exhaust ports and the exhaust gas outlet.

Abstract: An outboard motor having a four-cycle internal combustion engine as a power plant. The engine is provided with a cylinder head having intake passages that extend downwardly from inlet openings in a surface of the cylinder head to outlet openings that communicate with the cylinder bores so as to reduce uneven running as might be encountered if fuel were to puddle and collect in the induction system.

Abstract: A mounting arrangement for an accelerator pump and a choke actuation mechanism, which are used in conjunction with a plurality of charge formers, minimizes the girth of the engine while making these components more accessible and easing assembly. An actuator and a choke solenoid of the choke actuation system are mounted proximate to one another and partially between adjacent induction pipes of an induction system. This position allows these components to be located on an exterior side of the induction system without interfering with the protective cowling of the motor. The accelerator pump is mounted at the end of a series of charge formers, proximate to a throttle linkage which controls throttling devices of the charge formers. This position of the accelerator pump eases the installation of this component without increasing the girth of the engine.