Abstract: A fuel injection quantity control device for use with a two cycle engine being rotatably driven by receiving a fuel-air mixture injected into the engine based on fuel injection quantity instruction signals and the air supplied through an intake passage and ignition of the fuel-air mixture in a combustion chamber includes a rotational speed Ne detection device for detecting the rotational speed Ne of the two cycle engine and for generating a rotational speed Ne signal. An opening .THETA. detection device is provided for detecting the opening .THETA. of a throttle provided in an intake passage for regulating the supply of air and for generating an opening .THETA. signal. A basic injection quantity setting device is provided for setting a basis injection quantity of the fuel based on the rotational speed, Ne signal and the opening .THETA. signal.

Abstract: A fuel control solenoid valve for metering fuel flow through a low pressure fuel injection system of an internal combustion system is provided. The low pressure fuel injection system including the fuel flow solenoid valve is especially suitable for use in providing fuel to a two-cycle internal combustion engine, particularly those that are suitable for use as marine outboard motors. The fuel control solenoid valve includes a non-magnetic spacer which substantially prevents the development of engine surging as peak power conditions are approached or reached.

Abstract: Several embodiments of snowmobiles driven by an engine and variable belt transmission mechanism wherein the variable belt transmission has its input shaft journaled for rotation in the crankcase of the engine and driven from the engine crankshaft through a gear reduction so that the transmission loads are not carried by the crankshaft and wherein the crankshaft torsional vibrations are not transmitted to the transmission input shaft.

Abstract: A fuel injection system for a crankcase compression two cycle internal combustion engine wherein the amount of fuel supplied by the fuel injectors is decreased temporarily in the event the engine speed is accelerated after operating at a speed below a predetermined speed for a predetermined length of time. The amount of fuel reduction is determined by the length of time at which the speed has been below the predetermined speed and also the rate of opening of the throttle valve.

Abstract: A fuel supply system for a two cycle crankcase compression internal combustion engine embodying direct cylinder injection and carburetors for supplying a fuel air mixture to the crankcase chambers of the engine for high speed cooling. The direct fuel injectors supply the fuel at the low speed operation and a fixed amount of fuel at mid range and high speed, while the carburetor supplies only the mid range and high speed requirements of the engine in combination with the fuel injectors. Fuel is supplied first to the fuel bowls of the carburetors which have a vapor vent and then from the fuel bowls to the fuel injectors so as to avoid the necessity of a separate vapor separator for the fuel injectors.

Abstract: An air intake system for a marine propulsion engine having a U shaped configuration for facilitating water separation and to provide a long intake passage. An air flow sensor is positioned at the inlet opening of the inlet device with the length between the inlet opening and the intake ports being effective to dampen pulsations in the induction system from the air flow device.

Abstract: In a two cycle internal combustion engine (80) comprising three cylinders (22, 24, 26) vertically in-line, a single intake manifold (82) services all three of the cylinders, and a single fuel delivery device (84), such as a carburetor, on the manifold delivers fuel to each of the cylinders. Location and orientation of the three reed block openings (90, 92, 94) relative to each other and relative to the throttle bore (128) provide desired fuel distribution. Manifold structure, including internal dams (142, 146) and a deflector plate (138), prevents an overly rich fuel mixture in the lower cylinder (26) at idle, and prevents an overly rich fuel mixture in the upper cylinder (22) at running speeds above idle.

Abstract: In a two cycle internal combustion engine having three cylinders vertically in-line, a single intake manifold (210) services all three of the cylinders, and a single fuel delivery device on the manifold has a throttle bore (128a) at the uppermost reed block opening (204) and spaced above the other reed block openings (206, 208). The bottotm (220) of the throttle bore is spaced slightly above the bottom (222) of the uppermost reed block opening. A flow divider dam (228) in the manifold is below the uppermost reed block opening and a first portion (216) of the throttle bore, and divides the flow from the throttle bore and diverts to the upper cylinder a portion of the gravitationally induced vertical fuel flow which would otherwise drain to the lower cylinder during engine idle.

Abstract: A two cycle crankcase compression internal combustion engine having a main air/fuel injection system for injecting fuel and air directly into the combustion chamber and an auxiliary injection system for injecting fuel into the engine upstream of the combustion chamber for cooling the piston. A variety of arrangements of control strategies and auxiliary injection nozzle positions are illustrated and described.

Abstract: A system for operating a two-cycle spark ignition engine, comprising an ultrasonic atomizer that is disposed in an intake pipe of the spark ignition engine. When the engine is to be started, a fuel for starting is supplied to the ultrasonic atomizer, and after the engine has been started, a gas oil is supplied to the ultrasonic atomizer to atomize and spray it into the intake pipe, thereby enabling an increase in the flow rate of fuel atomized and sprayed by the ultrasonic atomizer and realizing combustion of gas oil, and thus achieving a lowering in the fuel cost, ensuring safety and making it possible to provide a lightweight emergency pump unit which is suitable for use in vessels, for example.

Abstract: A fuel injection system for a two cycle engine having main fuel injectors that inject directly into the engine combustion chambers and a sub or auxiliary fuel injector that injects into the induction system only under high load conditions to effect better piston cooling. Once the sub fuel injector begin to inject, then the amount of fuel per cycle injected by the main fuel injectors is decreased. The sub injector injects into a common manifold for a multiple cylinder engine and injects only one per crankshaft revolution.

Abstract: In a two cycle internal combustion engine (10), a reed block (52) has a fuel spray rail flow passage (72) integrally formed therein and supplying fuel atomized by combustion air flow therepast. The fuel spray rail passage extends longitudinally (78) along the apex (60) of a V-shaped reed block (52) at the downstream end thereof, and has discharge ports (74, 76) formed by openings through the sides (56, 58) of the V-shaped member, which ports (74, 76) are opened and closed by the downstream ends of the reed valve flaps (62, 64). When the reed valves are open, air flows across and parallel to the face of the discharge port opening and perpendicular to the direction of fuel flow out of such openings, for enhanced atomization of the fuel. When the reed valves are closed, the downstream ends of the reed valve flaps engage the reed block sides and cover and close the discharge ports such that fuel is blocked from draining into the crankcase.

Abstract: A two cycle, crankcase compression internal combustion engine which has one or more individually sealed crank chambers defined by one or more crank webs and a transfer passage associated with each chamber formed within the crankshaft body and cylinder block to provide increased flow area for the fuel/air mixture between the induction system and each cylinder. An inner wall forming portion of the crankcase body is expanded outwardly around crank webs and has an inwardly extending member associated with each crank web. A groove is formed in each inwardly extending member and cooperates with each of the outwardly expanding areas to define each of the transfer passages.

Abstract: A crankcase temperature sensor is provided for detecting temperature of a crankcase. A low speed basic injection pulse width is provided based on the detected crankcase temperature for low engine speed. An ordinary fuel injection pulse width is provided in accordance with engine operating conditions for ordinary engine operating condition. A comparator is provided for comparing the low speed injection pulse width and the ordinary fuel injection pulse width with each other. A larger injection pulse width is determined for injecting fuel.

Abstract: Disclosed herein is an engine comprising an engine block, a crankcase cover mounted on the engine block and including opposite first and second sides, a first carburetor mounted on the block at the first side of the crankcase cover, a second carburetor mounted on the block at the second side of the crankcase cover, a bracket supported by the crankcase cover intermediate the first and second carburetors, and a fuel supply component mounted on the bracket and comprising one of a fuel pump, an oil pump, a combined fuel and oil pump, a fuel vapor separator, a fuel vapor pump, a fuel filter, a primer fuel control valve, and a vacuum switch.

Abstract: An internal combustion engine comprising an engine block including first and second cylinders and first and second combustion air passages for supplying combustion air to the first and second cylinders, respectively, a first carburetor communicating with the first combustion air passage, having therein a first opening, and including a first fuel supply passageway communicating with the first opening, a second carburetor communicating with the second combustion air passage, having therein a second opening, and including a second fuel supply passageway communicating with the second opening, and a fuel manifold including an integrally molded first manifold portion comprising an elongated portion defining a first main passagewy having a closed end and an opposite open end, and a first nipple portion defining a first nipple passageway communicating betwen the first opening and the first main passageway and extending transversely to the first main passageway, and an integrally molded second manifold portion compris

Abstract: An outboard motor having an improved, compact induction system for a V-type engine. The induction system includes angularly related intake passages that are disposed at an angle that is less than the angle between the cylinder banks. Reed valves are interposed between the intake passages and the crankcase chamber. These reed valves extend perpendicularly to extensions of the cylinder bore axes. An improved balancing arrangement is also incorporated that comprises plenum chambers that surround the pairs of intake passages and the intake passages each communicate with the respective plenum chambers through relatively small openings.

Abstract: An internal combustion engine comprising an engine member including an intake manifold mounting face having therein a series of openings, an intake manifold including an exterior surface comprising an engine mounting surface on the manifold mounting face, and a carburetor mounting surface in spaced relation to the engine mounting surface, and a like series of intake passages extending between the mounting surfaces, terminating at the engine mounting surface in respective openings respectively located in alignment with the openings in the manifold mounting face, and terminating at the carburetor mounting surface in respective openings, a drain re-circulation system for delivering drains accumulating in the intake passages to intake passages other than the intake passages in which the drains accumulated, a system for supplying primer fuel to the intake passages, and a system for supplying operating fuel to a like series of carburetors, and a like series of carburetors on the carburetor mounting surface, which c

Abstract: A two-cycle engine with fuel injector comprises an engine body, a crank case defining crank chambers for respective cylinders, the crank chambers being provided with intake ports, throttle bodies, and fuel injectors. The throttle bodies comprise throttle passages and throttle valve means and the injectors are inserted in the throttle passages downstream of the throttle valve means. The throttle passages are connected to each other through a balance passage at portions downstream the throttle valve means. An air chamber may be formed on the way of the balance passage. The throttle passages connected by the balance passage to one group of cylinders having phase difference of 180.degree. of the reciprocating stroke.

Abstract: Several embodiments of additional fuel supply systems for internal combustion engines that supply supplemental fuel in addition to the normal charge forming device to satisfy certain specific requirements such as cold starting and cold running. In each embodiment, a separate fuel pump is provided for the supplemental fuel discharge but it is contained within and operated by the same operator of the main fuel pump for supplying fuel to the main fuel discharge. In some embodiments, the fuel pump is downstream of the supplemental fuel control and in other embodiments it is upstream of it. In one embodiment, the fuel pump and the supplemental control are all formed in the same housing.

Abstract: A two-stroke internal combustion engine comprising an engine block including a first exterior surface portion, a second exterior surface portion spaced from the first portion and having therein a crankcase-defining cavity, and a combustion air passage extending from the first exterior surface portion to the crankcase-defining cavity, an intake manifold fixed to the first exterior surface portion of the engine block and including therein a combustion air passage in alignment with the combustion air passage in the engine block, and a carburetor fixed to the intake manifold and having therein a combustion air passage in alignment with the intake manifold combustion air passage.

Abstract: A fuel injection controlling device for a two-cycle engine includes an electronic fuel injection system having a fuel injection quantity determining device for determining a fuel injection amount in response to a rotational speed of said engine and a throttle opening. A misfire detecting device is provided for detecting a misfire condition of said engine. Further, a device is provided for decreasing the amount of fuel injection upon transition from a misfire condition to a fired condition. The misfire detecting device includes a sensor for detecting an internal pressure of an intake air path, a storage device for storing therein an output value of the sensor and data of an intake air path internal pressure in a predetermined operating condition of the engine upon normal combustion, and a comparison device for comparing the output value with data read out from the storage means to detect a difference in pressure.

Abstract: Two embodments of induction devices for V-type engines wherein a compact configuration is achieved by having the inlet for the induction device disposed between the area defined by the associated induction devices of the engine.

Abstract: A fuel injection type two-cycle engine for motorcycles. A fuel injection valve for injecting fuel into an air intake passageway at a predetermined timing is disposed on the upstream side of a reed valve in the air intake passageway communicating with an interior of the engine via the reed valve, with the injection port thereof directed towards the reed valve. An air intake pipe forming the air intake passageway extends nearly in the vertical direction from the upper surface of a crank case at an middle position between a crank shaft extending in the widthwise direction of the vehicle body and a transmission shaft separated from the crank shaft in the back and forth direction and extending in the widthwise direction of the vehicle body, and a fuel injection valve protrudes from this air intake pipe in the back and forth direction.

Abstract: An air-fuel ratio control system for a two-cycle engine is disclosed, which includes a cylinder, a crank case serving also as a pressure chamber, a fuel injection unit including an injector and a pump, an engine speed detecting element for detecting the engine speed, and a throttle opening degree detecting element for detecting the opening degree of a throttle valve.

Abstract: An internal combustion engine comprising a crankcase adapted to rotatably support a crankshaft having an axis, the crankcase defining a plurality of crankcase chambers and including a generally flat manifold mounting surface including therein a first series of inlet openings aligned in the direction of the crankshaft axis, and a second series of inlet openings aligned in the direction of the crankshaft axis, the first and second series being laterally offset with respect to the direction of the crankshaft axis, and each of the inlet openings of the first and second series being respectively adapted to feed air to one of the crankcase chambers and having a minor dimension parallel to the crankshaft axis, a major dimension transverse to the crankshaft axis, and a portion overlapping the inlet openings of the other of the first and second series.

Abstract: Disclosed herein is a one-piece foam pattern for an intake manifold for a two cycle internal combustion engine, which pattern comprises a first surface for providing an intake manifold surface adapted to engage an engine block surface and having therein a generally rectangular opening, a second surface extending in generally spaced and parallel relation to the first surface and for providing an intake manifold surface adapted to engage a carburetor mounting surface, which second surface has therein a generally cylindrical opening, and a passage extending between the first and second surfaces and adapted to provide a fuel/air mixture passage in the intake manifold, which passage includes a first portion extending from the rectangular opening in the first surface and having a first transverse surface extending parallel to, and in spaced relation to, the first and second surfaces and having therein a second rectangular opening, which passage also includes a transition portion extending between the circular openi

Abstract: A fuel injector assembly and a low pressure fuel injection system incorporating the fuel injector assembly are provided. The fuel injector assembly includes a fastener housing that functions to secure a reed valve block to a mounting plate which separates the air intake manifold from the crankcase of the internal combustion engine. A fuel injector or check valve is secured to the fastener housing so that fuel directed to the fuel injector passes through the mounting plate and into the crankcase at a location in the vicinity of the air flow outlet from the reed valve block.

Abstract: Two embodiments of V-type two cycle crankcase compression internal combustion engines wherein the charge supplied to the crankcase chambers by a primary induction system is supplemented by a secondary induction system that communicates with the crankcase chambers between the primary system and the respective cylinder bank.

Abstract: Several embodiments of enrichment system for internal combustion engines for supplying enrichment fuel in response to a predetermined condition. In each embodiment, the engine has multiple chambers with multiple intake passages and a balance passage that interconnects at least some of the intake passages. The supplemental fuel is delivered to the balance passage for distribution to the chambers served by the interconnected intake passages. In some embodiments, the engine is provided with a charge forming system in the form of carburetors and in other embodiments, the engine is provided with a charge forming system in the form of fuel injection.

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 fuel control system for an internal combustion engine includes means for pneumatically amplifying sensed air flow pressure differential through an air intake venturi between a first combustion air pressure sensor outside the venturi and a second combustion air pressure sensor in the venturi. Pressure at the inner end of the second pressure sensor is reduced by altering the air flow path to create a vacuum at the inner end of the second pressure sensor relative to the remaining air flow through the venturi. A throttle plate in the venturi has a by-pass hole therethrough directing air flow along a given direction past the inner end of the sensor and through the by-pass hole when the throttle plate is in the idle position. The given direction of air flow past the inner end of the sensor prevents air flow into the inner end of the sensor tube to prevent an increase of sensed pressure thereat, and instead creates a vacuum to pull air out of the inner end of the sensor tube, to reduce pressure thereat.

Abstract: The present invention relates to a combustion chamber in which two flows of gas are admitted via ports at the bottom of the cylinder, one of the flows being a mixture containing fuel and the other being a flow of pure air. These flows are admitted so that they meet inside the chamber close to the wall opposite from an exhaust port (5) so that the mixture is confined and slowed down in a cavity (9) in the cylinder head while the flow of pure air is split by an edge (12) formed between said cavity and the bottom wall (11) of the cylinder head so that one portion of this air flow returns and scavenges the combustion chamber (1).

Abstract: A pulse balancing system is provided for a multicylinder two-stroke cycle internal combustion engine in which each cylinder is provided with its own mechanism for supplying an air-fuel mixture thereto. The vacuum pulse balancing system of the invention comprises a plurality of passages interconnecting each cylinder with one of the air-fuel mixture supply devices associated with one of the other cylinders, and one-way check valves provided in the passages. With the vacuum pulse balancing system of the invention, a vacuum pulse created by the piston in one of the cylinders is transferred not only to the air-fuel mixture supply device associated therewith, but also to the air-fuel mixture supply device associated with one of the other cylinders. This alleviates back pressure which may otherwise be caused in the air-fuel mixture supply device associated with the other cylinder due to the on-again off-again suction of air-fuel mixture therefrom to its associated cylinder.

Abstract: An internal combustion engine comprising a crankcase, cylinder, a transfer passage communicating between the crankcase and the cylinder and including a first point which is the lowest point in the transfer passage and at which the transfer passage has a first cross-sectional area, and a second point which is spaced from the first point and at which the transfer passage has a second cross-sectional area less than the first cross-sectional area, whereby air flow through the transfer passage establishes a static pressure differential between the first and second points, a sump communicating with the transfer passage at the first point, and a conduit utilizing the static pressure differential for pumping fluid from the sump to the transfer passage.

Abstract: A two cycle internal combustion engine is provided with a fuel system including a low pressure fuel pump (204) and solenoid valve (206) supplying and metering fuel to the engine crankcase through a fuel line, without a carburetor, without a high pressure fuel pump, without high pressure fuel injectors, and without a constant fuel pressure regulator. The system senses the amount of combustion air supplied to the engine, and senses fuel flow velocity using a restriction orifice in the fuel line producing a fuel pressure drop indicating fuel flow velocity. A conduit is connected between the crankcase at a transfer passage and the fuel line downstream of the restriction orifice and passes warm presurized air-fuel mixture from the crankcase through the transfer passage to the fuel line to improve fuel atomization.

Abstract: The present invention relates to an internal combustion engine cylinder assembly comprising a first cylinder having substantially vertically disposed interior walls defining a firing chamber therein; first piston means housed within the firing chamber and adapted for vertical reciprocation within the firing chamber; gas inlet channels means in the lower portion of the firing chamber; a crankcase housing having a gas compression chamber disposed therein; valve means adapted to permit fresh air mixture to be charged into the gas compression chamber upon the depressuring of the chamber; fuel introduction means for introducing liquid fuel into the upper portion of the firing chamber; second cylinder means positioned at the upper end of the first cylinder and having an exhaust chamber therein and a second piston means disposed within the exhaust chamber and adapted for vertical reciprocation therein, the exhaust chamber communicating with the upper end of the firing chamber; the second cylinder means being provide

Abstract: The present invention relates to an internal combustion engine cylinder assembly comprising a cylinder having substantially vertically disposed interior walls defining a firing chamber therein; piston means housed within the firing chamber and adapted for vertical reciprocation within the firing chamber; gas inlet channels in the lower portion of the firing chamber; a crankcase housing having a gas compression chamber disposed therein; valve means adapted for passing air into the gas compression chamber upon the depressuring thereof; cylinder closure means positioned at the upper end of the cylinder defining the upper end of the firing chamber and being provided with exhaust gas valve means, adapted for cyclic opening and closing to alternatively permit the removal of exhaust gases from the firing chamber and the pressuring of fresh fuel/air mixtures in the firing chamber; fuel introduction means for introducing fuel into the upper portion of the firing chamber; fuel ignition means for igniting a compressed f

Abstract: Disclosed herein is a two stroke internal combustion engine comprising first and second alternately fired cylinders, first and second crankcases respectively extending from the first and second cylinders, first and second carburetors respectively including first and second air induction passages respectively extending from the first and second crankcases, first and second reed valves respectively affording communications between the first and second crankcases and the first and second air induction passages, first and second throttle valves respectively movably mounted in the first and second air induction passages, first and second idle speed ports respectively communicating with the first and second air induction passages in the respective areas between the first and second throttle valves and the first and second reed valves, and a conduit communicating between the first and second idle speed ports.

Abstract: An induction system for a two-cycle crankcase compression internal combustion engine of the type employed in an outboard motor. As such, the engine has vertically disposed crankcase chambers. Two barrel carburetors serve the crankcase chambers of the cylinder pairs through an intake manifold which has respective intake passages that each slope downwardly so as to avoid variations in mixture strength.

Abstract: An engine apparatus comprising an internal combustion engine operable throughout a range of speeds including a minimum speed, a maximum speed, a first speed between the minimum speed and the maximum speed, and a second speed between the first speed and the maximum speed, the engine including an intake zone wherein relatively low pressure is created in response to engine operation, a primary fuel delivery system for delivering fuel from a fuel source to the engine for normal engine operation, a selectively actuatable secondary fuel delivery system for delivering enrichment fuel from a fuel source to the engine, and an electrical control circuit for selectively actuating the secondary fuel delivery system only when the pressure in the zone is below a predetermined level and the speed of the engine is above the first speed and below the second speed.

Abstract: Disclosed herein is a two stroke internal combustion engine comprising a cylinder, a crankcase extending from the cylinder, a piston reciprocal in the cylinder and defining, with the cylinder, a variable volume combustion chamber and defining, with the crankcase, a crankcase chamber having a volume which varies inversely with respect to the volume of the combustion chamber, a transfer passage communicating, subject to piston movement, between the crankcase chamber and the combustion chamber, an air intake passage extending from the crankcase chamber and including therein a throttle valve movable between opened and closed positions to control engine speed, a reed valve located between the air intake passage and the crankcase chamber for controlling communication between the air intake passage and the crankcase chamber, a first fuel injector communicating with the transfer passage, a second fuel injector communicating with the air intake passage between the reed valve and the throttle valve, and a controller fo

Abstract: An auxiliary fuel supply system is provided for a two cycle internal combustion engine (302). A first fuel line (350) supplies fuel from the fuel pump (338) to a solenoid (352) which is continuously cyclable between ON and OFF states during running of the engine, includig high speed operation where detonation may occur. Fuel then flows through a second fuel line (354) to a restriction orifice metering housing (356), and then to a plurality of third branch fuel lines (358, 384, 386, 388, 390 and 392) for delivery to respective cylinders. The restriction orifices provide a pressure drop from the second fuel line to the plurality of third fuel lines, to provide lower fuel pressure in the third fuel lines, to reduce the chance of leakage at the intake manifold (326), and also to reduce fuel pressure fluctuations in the third fuel lines otherwise due to cycling of the solenoid. Metering housing structure is disclosed.

Abstract: An outboard motor powered by a two-cycle crankcase compression internal combustion engine. A system is incorporated for draining condensed fuel from a plurality of locations in the engine induction system through a common conduit to a combustion chamber for combustion.

Abstract: A pulse fuel injector for a two-stroke internal combustion engine which utilizes a throttle body with a fuel venturi and a throttle valve in the body. A one-way pulse passage connects the crankcase of the engine and the venturi to direct air pulses to the venturi to aspirate fuel into the throttle body where it is drawn into the crankcase for transfer to the firing chamber of the engine.

Abstract: In a two cycle kerosene fueled internal combustion engine, the temperature of the kerosene-air mixture is raised sufficiently to enable starting by spark ignition, without the assist of gasoline. The combustion chamber (16) is temporarily contracted by a moveable cylinder head (40) during starting to temporarily increase the compression ratio and increase the temperature of the kerosene-air mixture by increased compression pressure. The exhaust port (30) is closed by an obstruction valve (88) during starting to trap the mixture in the combustion chamber (16) such that each compression charging stroke of the piston (4) adds further heat of compression to the mixture to further heat same. An electrical resistance heater wire (114) is provided in the kerosene-air transfer passage (24) between the crankcase (14) and the inlet port (26) to the combustion chamber (16) to further heat the mixture to facilitate ignition.

Abstract: A feedback fuel metering control system is provided for an internal combustion engine and eliminates the need for high pressure fuel injectors, a high pressure fuel pump and a constant fuel pressure regulator. The system senses the amount of combustion air supplied to the engine, senses fuel flow velocity, and controls the amount of fuel supplied according to the amount of combustion air the fuel flow velocity.

Abstract: A two-cycle engine includes an engine body having at least one cylinder, the cylinder having an exhaust port and at least one scavenge port disposed generally in opposed relation to the exhaust port. A piston is received in the cylinder for reciprocal movement therealong and having an outer peripheral surface for closing the exhaust and scavenge ports during the reciprocal movement thereof. The piston has a transverse bore extending therethrough with opposite ends of the transverse bore opening to the outer peripheral surface of the piston. The opposite ends of the transverse bore is capable of being brought into facing relation to the opposed exhaust and scavenge ports, respectively, during the reciprocal movement of the piston. A hollow wrist pin is received in the transverse bore and retained therein, one end of the wrist pin being closed.

Abstract: In a two cycle internal combustion engine (2), a fuel injection system is provided with a low profile compact intake manifold (22) mounted to the crankcase (8) by an adaptor plate (24) and defining an intake air flow path in a first direction (28) behind the manifold (22) through a gap between the manifold (22) and the crankcase (8) provided by the adaptor plate (24). Intake air then flows (32) into throttle bore passages (30) from behind the manifold and then reverses direction and flows through supply passages (34) having fuel injectors (38) and then into the crankcase (8). The passages share a common plenum (42) within the manifold. The fuel injectors (38), their electrical connectors (48) and a common rigid fuel supply rail (44) are all in the common plenum (42) entirely within the low profile manifold (22) and sealed from moisture and salt in a marine environment.

Abstract: A system for mixing fumigation fuel with the intake air in a compression ignition engine includes a variable area venturi in an engine intake air duct to draw controlled amounts of a pre-mixed fumigation fuel/air mixture into the main air stream in proportion to the amount of suction created downstream of the variable area venturi by the engine air flow. The variable area venturi creates a pressure depression proportional to the engine air flow motivating the fumigation fuel/air mixture to flow into the engine along with the main air stream at a rate related to the engine load and speed. The variable area venturi includes a housing having a downstream branch connected to a conventional demand-type mixer which is supplied with the fumigation fuel via a demand-type regulator, and air through a filter from the atmosphere. The variable area venturi is formed by a spring-loaded, normally closed flapper valve which variably opens in response to air drawn through the housing by the engine.