Abstract: An internal combustion engine comprising a cylinder block which defines a cylinder, a crankshaft bearing supported at least in part by the cylinder block, a crankshaft which is rotatably supported by the crankshaft bearing, a piston slidably housed in the cylinder, a connecting rod having one end connected to the piston and having an opposite end connected to the crankshaft, a cylinder head mounted on the cylinder block, a camshaft at least partially supported by the cylinder head for rotation relative thereto, an oil pump having an outlet, a first oil conduit communicating between the oil pump outlet and the crankshaft bearing, an oil filter communicating with the first oil conduit for filtering oil only in the first oil conduit, and a second oil conduit communicating between the oil pump outlet and the camshaft, oil in the second oil conduit being unfiltered between the pump outlet and the camshaft.

Abstract: A lubricating system for a reciprocating machine such as a two cycle internal combustion engine having the cylinder bores horizontally disposed. A drain system is provided for draining lubricant from the lowermost crankcase chambers to the upper cylinders so as to maintain uniformity of lubrication and insure even and smooth running. A check valve is provided for precluding reverse flow and the lubricant is delivered both to the crankcase chambers and to the piston through either the piston and/or cylinder liner. The lubricant supplied to the piston is supplied at its upper area so as to insure complete lubrication of its circumference and of the associated cylinder bore.

Abstract: A motor vehicle containing a two-cycle, crankcase compression, internal combustion engine having direct lubricating systems for supplying lubricant to the sliding surfaces of the piston and cylinder bore for each cylinder of the engine, separate pumps for delivering lubricant to the crankshaft bearings associated with each cylinder of the engine and a system for delivering lubricant to the engine for the remaining components through the induction system.

Abstract: Disclosed herein is a four-stroke internal combustion engine including a cylinder, a device for feeding fuel to the cylinder, a sealed crankcase chamber associated with the cylinder, a piston reciprocally movable in the cylinder and relative to the crankcase chamber to effect alternation of the pressure therein in response to piston reciprocation, an oil sump adapted to contain lubricating oil, a conduit system for recirculating oil from the sump to the crankcase chamber and from the crankcase chamber to the sump in response to alternation of the pressure in said crankcase chamber, an oil pump communicable with the oil sump and with the fuel feeding means, and a conduit operably connected to the oil pump and to the crankcase chamber so as to effect delivery of oil from the sump to the fuel feeding device in response to alternation of the pressure in the crankcase chamber.

Abstract: A lawn mower has at least one rotary cutting blade and an internal combustion engine for operating the at least one cutting blade, wherein the lawn mower can be operated on a substantially horizontal surface, while inclination of the mower on various surface slopes is also possible, while still maintaining adequate lubrication of the operating parts of the mower.

Abstract: Disclosed herein is an outboard motor comprising a steerable and tiltable propulsion unit including a lower unit including a vertically extending drive shaft housing, a drive shaft extending vertically in the drive shaft housing and located in a plane extending in a fore and aft direction, and a propeller shaft driven by the drive shaft and extending in the fore and aft plane, and a powerhead comprising a four stroke engine including a vertically extending crankshaft located forwardly of the drive shaft and in laterally spaced relation to the fore and aft plane, a cylinder extending horizontally and radially from the crankshaft and at an acute angle to the fore and aft plane, a camshaft extending generally vertically in the fore and aft plane and in vertical alignment with and in driving connection with the drive shaft, and a gear set drivingly connecting the crankshaft and the camshaft for rotatably driving the camshaft at a rotational speed which is one-half of the rotational speed of the crankshaft.

Abstract: Disclosed herein is an outboard motor comprising a cylinder block having a horizontally extending lower mounting surface and a rearwardly located vertically extending cylinder head mounting surface, a cylinder head fixed to the cylinder head mounting surface, extending rearwardly from the cylinder block, and including a bottom wall portion having therein a rocker arm support shaft aperture and a camshaft aperture, a camshaft supported vertically and horizontally in the cylinder head about an axis located rearwardly of the cylinder head mounting surface, a rocker arm support shaft supported vertically and horizontally in the cylinder head about an axis located rearwardly of the cylinder head mounting surface, and a lower unit including a driveshaft housing supporting a propeller fixed to the cylinder block lower mounting surface and including an upper rearward profile located forwardly of the camshaft aperture and the rocker arm support shaft aperture and extending so as to enable, when the housing is fixed to

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 engine E of an outboard motor O includes a carburettor 29 at an upstream end of an intake manifold 28, and an air intake 30 is detachably fixed to the carburettor 29 by two bolts 44. A cylinder block 21 of the engine E and a coupling portion 30-2 of the air intake 30 are interconnected through blow-by gas passages 40 and 41 with an oil separating chamber 39 interposed therebetween. The coupling portion 30-2 is provided at a location offset upwardly from axes of the two bolts 44. Therefore, both of the operation of the bolts 44 for attaching and detaching the air intake 30 and the operation of attaching and detaching the blow-by gas passage 41 to and from the coupling portion 30-2 can be conducted without any hindrance.

Abstract: A lubrication system for the internal combustion engine of a motorcycle that includes a pump that outputs a constant amount of fluid per cycle of operation and a delivery valve which selectively passes lubricant to the engine or returns lubricant back to the system to vary the amount of lubricant supplied by the lubricant pump. The system is designed so as to self purge air from the system by mounting the lubricant pump and the delivery valve in close proximity to each other and at a lower level than the lubricant storage tank. In addition, the engine is supplied with arrangement to preclude lubricant from draining into the engine through the delivery valve when the engine is not running.

Abstract: A number of embodiments of outboard motors including dry sump lubricated four cycle internal combustion engines. The dry sump lubrication system includes a scavenge pump for drawing lubricant drained from the engine lubricating system through an inlet port and returns it to a dry sump reservoir through an outlet port and a pressure pump that draws lubricant from the dry sump lubricant reservoir through an inlet port and delivers it the engine lubricating system through an outlet port. At least one of the ports of each of the pumps is positioned above the normal lubricant level in the lubricant reservoir when it is filled with the normal volume of lubricant so as to insure that lubricant will not drain back into the engine when the pump system is not operating. Various arrangements for achieving this result and for cooling the lubricant are described.

Abstract: A four-stroke cycle engine unit for a working machine has generally a lubricating device for lubricating mechanical parts in a valve chamber and a cam chamber. The lubricating device comprises a body which has the cam chamber and a crank chamber, a cylinder head and a head cover having the valve chamber, and a mechanism for preventing a lubricating oil from escaping from at least one of through holes for push rods provided in a wall of the valve chamber and the cam chamber.

Abstract: A four-stroke cycle engine unit for a working machine has generally a lubricating device for lubricating mechanical parts in a valve chamber and a cam chamber. The lubricating device comprises a body which has the cam chamber and a crank chamber, a cylinder head and a head cover having the valve chamber, and a mechanism for preventing a lubricating oil from escaping from at least one of through holes for push rods provided in a wall of the valve chamber and the cam chamber.

Abstract: An engine for an outboard engine assembly includes a cylinder block with at least one horizontal cylinder defined therein, an oil pan disposed downwardly of the cylinder block, a cylinder head coupled to the cylinder block, and a head cover coupled to the cylinder head. The engine assembly also includes a valve operating mechanism chamber defined jointly between the cylinder head and the head cover, a lubricating oil supply passageway for supplying lubricating oil from the oil pan to at least the valve operating mechanism chamber, and a lubricating oil return passageway for returning lubricating oil from at least the valve operating mechanism chamber to the oil pan. The lubricating oil return passageway has openings for introducing lubricating oil from the valve operating mechanism chamber. The openings are defined in inner surfaces, respectively, of the cylinder head and the head cover which face a bottom of the valve operating mechanism chamber.

Abstract: An improved crankcase gasket, for use in an internal combustion engine with a vertical crankshaft, having web portions that substantially cover the oil sump. The construction of the crankcase gasket baffles oil thrown around the inside of the engine by mechanical turbulence and prevents excess oil from reaching the cylinder bore. Gasket material under the valve spring box drain operates as a check valve and eliminates the need for an expensive valve stem valve. Oil temperature is reduced with an increased ability for engine operation at greater angles of crankshaft tilt from vertical.

Abstract: A single cylinder, overhead cam, internal combustion engine lubrication system where lubricating oil is pumped from a crankcase oil sump through oil passages to the upper bearings of the crankshaft and camshaft. The oil leaks from the bearings, adheres and flows down the shafts which is flung by rotation thereby lubricating the cam lobes and valve tappets. Oil, accumulating in the cam chamber sump, lubricates the lower camshaft bearing before being pumped through the closed loop circulatory system.

Abstract: An OHC vertical crankshaft engine, comprising: a vertically disposed crankshaft having a first timing pulley at its lower end; a cooling fan attached to an upper end of the crankshaft; a camshaft extending in parallel with the crankshaft at a cylinder head end of the engine and having a second timing pulley at its lower end; and a timing belt passed around the timing pulleys. Thus, the need for lubrication for the transmission mechanism between the crankshaft and the camshaft is substantially eliminated, and the noise generation is reduced. Additionally, since the upper part of the cylinder head is directly exposed to the cooling air produced by a fan provided at an upper end of the crankshaft, a high engine cooling efficiency can be achieved. This effect is even more enhanced if the exhaust port of the engine is disposed above the intake port and extends horizontally and linearly away from the engine.

Abstract: A bearing for receiving a crankshaft positioned in a crankcase of an inboard/outboard internal combustion engine which includes a seal member for sealing the inside of the bearing so as to prevent corrosion of the bearing. Preferably, the crankcase includes a plurality of crank chambers to accommodate a crankshaft rotatably received by a plurality of bearings, each of which includes a seal member.

Abstract: A marine propulsion device comprising a gear housing adapted to be mounted on a transom of a boat, a first gear rotatably supported by the gear housing and adapted to be driven by an engine, a second gear which is rotatably supported by the gear housing, which is driven by the first gear and which is adapted to be drivingly connected to a propeller, a third gear driven by the second gear, and an arrangement for lubricating the third gear.

Abstract: A liquid cooled internal combustion engine, comprising: an integrally cast engine main body including a cylinder block, a cylinder head, and a crankcase skirt, a crankcase cover attached to an open end of the skirt to define a crankcase therein, a crankshaft extending vertically in the crankcase and rotatably supported by the skirt at its both ends, a camshaft rotatably supported by the cylinder head and extending in parallel with the crankshaft, a timing belt passed around pulleys mounted on lower ends of the camshaft and the crankshaft, respectively, and extending in a belt chamber defined in the cylinder block along a lower side of the cylinder bore; a cooling liquid jacket defined in the cylinder block along upper and lateral sides of the cylinder bore. The jacket may be formed during the casting process by pulling a core either upwards or toward the open end of the skirt. The cooling liquid may consist of the lubricating oil for the engine.

Abstract: A lubricating oil pump device of an engine comprises an upper and a lower pump case and a rotary pumping mechanism of the internal-gear, one-tooth difference type housed within a housing formed between the upper and lower pump cases. Both the pump cases have oil reserving oil sumps formed therein, thereby to reserve some oil in the pump device even when the engine is stopped for a long period. Then, when the engine is restarted and the pumping mechanism operates, the oil thus reserved in the oil sumps is contacted by the moving pumping mechanism and is induced out to form oil films on the surfaces of the pump cases and of the pumping mechanism. Thus instant lubrication and sealing for effective suction are assured.

Abstract: An oil cooler for small internal combustion engines is provided. The oil cooler comprises a heat exchanger mounted on the external surface of the engine crankcase, directly below the flywheel. The heat exchanger has an inner serpentine passageway in flow communication with the lubrication path of the engine oil. The heat exchanger further has a plurality of external fins, said fins being positioned directly below the flywheel. The flywheel includes a plurality of inlet apertures for drawing in cooling air to be blown over the heat exchanger.

Abstract: An internal combustion engine having a vertically oriented crankshaft and a horizontally oriented cylinder bore and including a plurality of lubrication sites to be pressure lubricated. A first upstanding wall extends upwardly from the top wall of the crankcase and circumscribes and defines a first chamber. A breather passage communicates crankcase gases from the crankcase into the first chamber. A drain passage communicates oil separated from the crankcase gases in the first chamber into the cylinder bore below the piston and is positioned along the cylinder bore so as to be periodically occluded by the piston during reciprocation thereof. A second upstanding wall extends upwardly from the top wall of the crankcase in spaced relationship to at least a portion of the first wall, and defined together with the first wall a second chamber therebetween.

Abstract: An oil pump mounting system for an internal combustion engine of the type in which the oil pump is disposed in a pump housing formed integrally with an oil pan and feeds an oil into an oil passage extended through the output shaft of the engine. The oil pump mounting system comprises a driving shaft of the oil pump supported at both ends by the output shaft of the engine and a bearing portion formed in the oil pan, and an oil suction port formed through one side of the pump housing communicated with the surface of the oil pump on the side of the bearing portion. Thus ensuring operation even when the engine is inclined.

Abstract: A lubricating apparatus for an engine of vertical crankshaft type according to the present invention includes an oil pan arranged at a lower portion of a crank case for supporting a vertical crankshaft, and an oil tank having a volume larger than that of the oil pan arranged independently from the oil pan, and wherein an outlet of the oil tank is communicated with each of lubricating portions through the oil pan, an intake portion of the oil tank is communicated with the oil pan and the oil in the oil pan is fed into the oil tank by means of an appropriate oil feeding mechanism.

Abstract: A lubrication device for a vertical crank shaft engine. A portion of a crank case, which houses the crankshaft with a small clearance at a given range of the lower side of the crankshaft extending vertically and expands upwards of the housing portion, forms an oil reservoir between the crankshaft, and a pumping member fixed to the crankshaft for rotation is provided in the lower portion of the oil reservoir.

Abstract: The present invention is a self-lubricating bearing for a vertical shaft engine. A stub disposed within the journal bearing has a downwardly facing pocket which propels oil upward by centrifugal force during rotation of the shaft. The upwardly forced oil serves to lubricate the bearing above the stub. The lubrication system can be employed in both stub shaft and through shaft bearings.

Abstract: The present invention is a lubrication system for an internal combustion engine. lubricating oil flows through a central bore of a camshaft, and the camshaft sprays oil into a journal bearing. The crankshaft and camshaft are configured so that they are in phase, whenever the camshaft is closest to the camshaft during a rotation, the camshaft sprays oil into the journal bearing. Since the crankshaft has twice the rotational velocity of the camshaft, two spray holes are provided in the camshaft so that a spray hole supplies oil on each cycle of the crankshaft rotation.

Abstract: An air-cooled engine having a vertical crankshaft and a horizontal cylinder. The cylinder is cast aluminum alloy and has the intake and exhaust valves located next to one another on one side of the cylinder, with the carburetor located on the other side of the cylinder. An intake cross-passageway integrally cast in part with the cylinder passes under the piston bore to connect the intake valve to the carburetor. For casting purposes, the lower side of the passageway is open in the cylinder casting to permit removal of the passageway casting core and forming an opening having side walls extending transverse to the piston bore extending from the passageway to the exterior of the cylinder. A cover having side walls corresponding to and lying adjacent the side walls of the opening is disposed in the opening. The cover has a curved inner surface corresponding to the curvature of the passageway.

Abstract: A breather device of an engine comprises a pressure chamber communicating with the crank chamber of the engine, an oil sump chamber communicating via a pressure-responsive valve with said pressure chamber, a breather chamber communicating via an oil holding wall with said oil sump chamber and communicating also with the engine air intake system, and oil return passage means having a downstream end submerged in oil in an oil pan, said oil sump chamber being communicative with the oil return passage means.

Abstract: In a two-cycle internal combustion engine (2), the sidefaces (60, 62) of the connecting rod (48) have a polymeric material coating thereon, such as polytetrafluoroethylene, PTFE, providing a bearing between the sidefaces (60, 62) and the crankfaces (38, 40) of the crankarm discs (34, 36) of the crankshaft (24), to prevent galling and eliminate the need to silver plate the sidefaces (60, 62).

Abstract: An arrangement and structure for an oil pan system to permit mounting a vertical in-line engine in a vehicle in a horizontal or nearly horizontal attitude includes a cylinder block of the engine having an opening on the side wall thereof, a cover attached to the cylinder block where an ordinary oil pan is usually mounted, an adapter plate fastened to the lower side wall of the cylinder block and bottom of the cover, and an oil pan attached to the lower surface of the adapter plate. The adapter plate allows the oil pan to extend and always remain below the cylinder block, so that the return paths from the lubricated portions of the engine to the oil pan are shortened.

Abstract: Several embodiments of outboard motors having fuel injected internal combustion engines. In each embodiment, the fuel injection pump is disposed so that its drive shaft extends horizontally and so that its outlets for pressurized fuel are below its top end to avoid the inclusion of air in the fuel. In each embodiment, the fuel injection pump has an air vent that is vented back to a remotely positioned fuel tank.

Abstract: A cam shaft for engine is constructed such that the cam shaft driven by a crankshaft is rotatably supported at both ends by respective journal bearing boxes. Either one of the journal bearing boxes is fed with pressure oil from an oil pump to cause the oil pressure gathered within the journal bearing box to act upon the end face of the cam shaft so that the cam shaft is normally biased in a constant axial direction.

Abstract: An improved lubricating system for an internal combustion engine having a horizontally disposed cylinder. The engine is provided with overhead valves that are disposed vertically above each other and which reciprocate about horizontally extending axes. The exhaust valve lies above the intake valve and the lubricating system delivers lubricant first to the exhaust valve and then by gravity to the intake valve. In addition, an arrangement is provided for submerging the valve operating tappets in lubricant to effect lubrication and silencing.

Abstract: In a marine outboard engine unit driven by a four-stroke-cycle engine, the vertical crankshaft is aft of the cylinders and the camshaft and drives the camshaft via a sprocket-and-chain mechanism, the lower end of the camshaft being coupled to the extension drive shaft which is coupled to the propeller at the lower end of the lower unit, and the carburetor for each cylinder is at the forward part of the engine. By this arrangement, "oil rise" of the lubricating oil in the engine is prevented when the boat hull, under way, assumes a bow-up attitude, and the speed-reduction ratio from crankshaft to propeller can be reduced, whereby a high-speed, high-power-output engine can be used.

Abstract: In a two cycle internal combustion engine (2), the sidefaces (60, 62) of the connecting rod (40) have grooves (64) formed therein dragging lubricant from the fuel-air-lubricant mixture in the crankcase (8) along the crankfaces (38, 40) of the crankarm discs (34, 36) of the crankshaft (24), providing a hydrodynamic bearing with a layer of lubricant separating the sidefaces of the connecting rod from the crankfaces of the crankarm discs such that the sidefaces of the connecting rod ride on a layer of lubricant, and eliminating the need to silver plate the sidefaces of the connecting rod.

Abstract: A vertical shaft internal combustion engine particularly adapted for powering a rotary type lawn mower. The engine is provided with a baffled crankcase so as to minimize the adverse effects of oil "sloshing" within the crankcase while, at the same time, permitting flow between the baffles. In addition, an oil slinger arrangement is incorporated that is also baffled so as to reduce frothing in the crankcase to reduce aeration of the oil in the crankcase and also to direct the oil flow from the slinger.

Abstract: A cooling system for V-type engine comprises rows of left and right cylinders arranged in V-type and having coolant jackets, respectively. A coolant pump having a pump shaft parallel to a crankshaft is arranged with a V-bank and at a place away from each cylinder in an axial direction of said crankshaft, and coolant jacket inlets are provided on the side of the coolant pump of each cylinder. Alternately, the coolant jacket inlets of the cylinders are opened respectively at one end face in the direction of the crankshaft of a crankcase-forming member, and a distributing exit passage is defined by joint faces of said crankcase-forming member, a pump casing and a pump casing cover respectively.

Abstract: A lawn mower or other similar walk behind type of implement that is designed to be operated in a normally erect position and which is tilted to its side for servicing. An engine is provided for the lawn mower having an output shaft rotatable about a vertically extending axis. The engine includes a lubricating system incorporating a crankcase in which the engine output shaft rotates and a crankcase ventilating system. The crankcase ventilating system is designed so as to prevent lubricant from flowing into the induction system when the engine is tilted on its side.

Abstract: Several embodiments of outboard motors embodying four-cycle engines and improved lubricating systems therefor. In all of the embodiments, an oil reservoir is provided in the drive shaft housing and a combined screen and drain plug assembly filters the oil flowing from the oil reservoir to the engine lubricating system and for facilitating servicing of the screen by removal of the drain plug. In one embodiment, the oil reservoir is formed integrally with the drive shaft housing. A pressure relief valve depends into the oil reservoir and is carried by a plate that connects the engine to the drive shaft housing for facilitating servicing and reducing the likelihood of leakage back of oil to the engine when the outboard motor is tilted up. An improved relief valve screen assembly is also illustrated in one embodiment where in the screen may be bypassed if it becomes clogged.

Abstract: A marine propulsion device comprising a lower unit including a rotatably mounted propeller, and an internal combustion engine drivingly connected to the propeller, the engine including an engine block, a crankshaft rotatably supported by the engine block and including an end portion projecting from the engine block, a flywheel including a hub, the hub being mounted on the end portion of the crankshaft and having an outer surface, and a bearing located between the engine block and the outer surface of the flywheel hub for facilitating rotation of the flywheel relative to the engine block.

Abstract: A liquid-cooled engine of the vertical shaft type has a row of left and right side cylinders arranged in a V-shape as viewed from the above. The cooling water jackets of the left and right side cylinders are connected to each other at the highest ends of the cooling water jackets at the sides of cylinder heads of the cylinders through a communicating passage, a thermostat chamber is provided at the highest end of the cooling water jacket of one of the cylinder heads which is located lower than the other cylinder head, the communicating passage being connected at its one end to the thermostat chamber.

Abstract: An overhead valve engine including a bore for receiving a push rod for actuating a suction valve and a bore for receiving a push rod for actuating a discharge valve. Blowby gas is introduced into one of the bores from a crank chamber and supplied to the other bore via a rocker arm chamber to lubricate the push rods with oil mist in the blowby gas. After lubricating the push rods, the blowby gas is released via the breather gas from the engine.

Abstract: A vertical shaft V-type engine having a vertical crankshaft and a pair of right and left hand cylinders arranged in V-shape, the engine comprising a carburetor arranged within a V-bank defined between both cylinders and an air cleaner arranged upwardly of the carburetor. The engine is also provided with an air fan and the air cleaner is arranged adjacent to a fan housing of the air fan.

Abstract: A lubrication and circulation system is provided for a marine drive lower gear case (4). A self-lubricating heat conducting flat thrust washer bearing (26) around the drive shaft (6) has a bottom horizontal surface (30) engaging the top of the pinion gear (10) at the bottom of the drive shaft (6) without needle bearings or roller bearings interposed therebetween. Lubricant frictionally dragged by the top of the pinion gear (10) across the bottom horizontal surface (30) of the thrust bearing washer (26) is diverted along the slants of slots (36 and 38) at an angle to the radius (40) inwardly toward the drive shaft (6) rotating therein. Upper and lower self-lubricating heat conducting sleeve bearings (18 and 20) mount the drive shaft (6) for rotation in the lower gear case (4) without needle bearings or roller bearings therebetween.

Abstract: Several embodiments of outboards motors embodying four-cycle engines and improved lubricating systems therefor. In all of the embodiments, an oil reservoir is provided in the drive shaft housing and a combined screen and drain plug assembly filters the oil flowing from the oil reservoir to the engine lubricating system and for facilitating servicing of the screen by removal of the drain plug. In one embodiment, the oil reservoir is formed integrally with the drive shaft housing. A pressure relief valve depends in to the oil reservoir and is carried by a plate that connects the engine to the drive shaft housing for facilitating servicing and reducing the likelihood of leakage back of oil to the engine when the outboard motor is tilted up. An improved relief valve screen assembly is also illustrated in one embodiment where in the screen may be bypassed if it becomes clogged.

Abstract: The two-cycle internal combustion engine has a sump in a lower portion of the crankcase for collecting engine fuel drains and a crankshaft bearing lubrication system including a first conduit means connecting the upper crankshaft bearing in communication with the engine intake manifold, second conduit means connecting the upper crankshaft bearing in liquid communication with the sump and having an intermediate portion or reservoir, and third conduit means connecting the crankcase in communication with the reservoir. A first check valve located between the sump and the reservoir permits fuel drains to flow from the sump upwardly toward the upper crankshaft bearing in response to a suction created in response to the low pressure or vacuum in the intake manifold and prevents backflow from the reservoir to the sump.

Abstract: A general-purpose internal combustion engine has a vertically extending crank shaft. The engine includes intake and exhaust valves disposed in overhead relationship to a cylinder head having an intake passage connected to the intake valve and an exhaust passage connected to the exhaust valve, the intake and exhaust passages being defined in opposite sides of the cylinder head. A carburetor and an air cleaner are coupled to the intake passage and located on the same side as the intake passage, and a muffler is connected to the exhaust passage and located on the same side as the exhaust passage. With this arangement, the engine has as small a height as possible.

Abstract: An improved lubricating system for a two-cycle outboard motor having a vertically extending crankshaft. The lubricating system employs a crankshaft driven pump and circulating system that permits pressure lubricating without necessitating elongation of the crankshaft or engine. The engine is enclosed within a cowling and an oil sump is conveniently located within the cowling and is accessible through a cover door of the cowling for replenishment of the oil supply without removal of the cowling.