Abstract: A small watercraft adapted to seat one or more riders in motorcycle fashion and which has a hull configured so as to facilitate leaning without capsizing. The foot area for the riders is such that a rider may either sit on the seat in straddle fashion or stand behind the seat and may move between these positions easily and while the watercraft is in motion.

Abstract: A fuel injection system for an internal combustion engine having a fuel pump drive for driving a fuel pump of the injection system at different speed ratios depending upon the engine conditions. The pump is driven at a higher speed during starting than when the engine is operating.

Abstract: Several embodiments of engine intake systems that improve the charging efficiency by providing a closed branch passage which forms a volume in the intake tract between the throttle valve and the point of discharge into an engine chamber. The illustrated embodiments of the application of this concept is to both four and two cycle engines. In addition, a plenum chamber is illustrated for permitting the effective volume of the branch passage to be increased without unduly increasing its length. The branch passage outlet in certain embodiments is oriented so that its discharge during the intake cycle increases turbulence to improve combustion efficiency.

Abstract: A jet propulsion unit for powering a watercraft that is contained within a tunnel on the underside of the hull of the watercraft. The jet propulsion unit is rotatable about a longitudinally extending axis to rotate its water inlet opening from a downwardly facing position to a raised, out of the water storage and service position The drive for rotating the jet propulsion unit is positioned forwardly of the tunnel and out of the body of water in which the watercraft is operating.

Abstract: An arrangement for determining the position of a vehicle along a two dimensional course and for steering the vehicle to maintain a desired preset path. A sensing device is incorporated that includes markers placed at known locations and an optical sensor sequentially makes three measurements of the angle between the vehicle and the sensors, the angular course of the vehicle and the distance travelled from the last sensing so as to provide an indication of the actual vehicle position and course. The actual position is then compared with the desired position and corrections are made by the steering mechanism.

Abstract: A number of embodiments of watercraft having jet propulsion units contained within a tunnel in the hull and wherein the jet propulsion unit is pivotal about a first transversely extending horizontal pivot axis for bringing the jet propulsion unit through trim adjusted positions to an upward out of the water position. In addition, the jet propulsion unit is rotatable about a horizontal longitudinally extending axis so that its downwardly facing water inlet portion may be rotated upwardly for access through an access opening in the hull for servicing. In one embodiment, the jet propulsion unit is only rotatable about the horizontal longitudinally extending axis. A number of embodiments of rudder assemblies are also depicted supported by the steering nozzle for generating steering effects when the steering nozzle is not generating a significant steering effect and which may be pivoted to an out of the water position for protection when underwater obstacles are struck.

Abstract: An outboard motor having an air compressor for delivering compressed air to a scavenging system for the engine. The air compressor is designed so that when the engine is not running, any moisture which may be present in the pumping cavity of the air compressor will drain out of the outlet opening of the compressor.

Abstract: An improved scavenging system for a two cycle internal combustion engine wherein the cylinder block of the engine is provided with an internal plenum chamber that surrounds the lower portion of the cylinders and which supplies the scavenge ports of the engine. In this way, it will be ensured that the proper air flow can issue from each scavenge port.

Abstract: An outboard motor having an improved cooling system wherein liquid coolant is circulated through an exhaust manifold cooling jacket then through a cylinder head cooling jacket and then through an upper portion of the cylinder block cooling jacket. A thermostatic valve controls the flow from the upper cylinder block cooling jacket through a lower cylinder block cooling jacket so as to avoid quenching of the intake charge by coolant which has not reached operating temperature.

Abstract: Two embodiments of air/fuel ratio adjusting systems for gaseous-fueled internal combustion engines. In each embodiment, a pressure regulator supplies regulated fuel in gaseous form from a source in which it is stored in a liquid form to a charge former that has a fuel control device such as a needle valve. The air/fuel ratio is maintained constant by mixing atmospheric air with the fuel before the charge former fuel control device under the control of an oxygen sensor in the exhaust system. In one embodiment, an enrichment system is also incorporated for supplying enrichment fuel under acceleration or cold starting conditions.

Abstract: A motorcycle powered by a two cycle crankcase compression fuel injected internal combustion engine. The injection system for the engine includes a main fuel air/injector that injects fuel directly into the combustion chamber and a second or auxiliary fuel injector that injects fuel into the induction system for the engine. Control means control the fuel injectors so that the second or auxiliary fuel injector supplies fuel only during starting and high load, high speed conditions. The engine components are laid out in such a way that the spark plugs of the engine and the fuel injector will each be exposed to unobstructed air flow for cooling.

Abstract: A number of embodiments of tappet assemblies comprised of a main body element formed from a lightweight material and an engaging element adapted to engage the valve stem and formed from a harder, more wear resistant element. The engaging element and the main body element have cooperating cylindrical surfaces with a discontinuity in one of these surfaces into which the material of the other element is plastically deformed on assembly for locking the elements to each other.

Abstract: A motorcycle powered by a two cycle internal combustion engine having an improved induction system that has a vertically extending intake pipe so as to permit a wide latitude of leaning of the motorcycle without interference from the induction system. The induction system serves the crankcase of the engine through a rotary plate type valve that has a helical connection to the engine output shaft so that the timing of the opening and closing of the intake port can be adjusted. A servo motor adjusts the helical connection under the CPU so that the timing change mechanism need not be powered directly by the engine.

Abstract: A number of embodiments of scavenging port configurations for two-cycle internal combustion engines wherein the a scavenge port is formed adjacent the exhaust port and is masked by a cylinder liner so as to avoid the escape of scavenging gases to the exhaust port, particularly at the end of the scavenging cycle.

Abstract: A snowmobile having an improved cooling arrangement including a front mounted radiator and a ducting system for ducting cooling air through the radiator and away from the windshield and rider's hands on the handlebars of the snowmobile.

Abstract: A small watercraft embodying an improved exhaust system that is substantially completely watercooled by a cooling jacket. The exhaust system includes an elastic joint that is also completely surrounded by the cooling jacket so as to insure adequate cooling under all running conditions. A damming arrangement is incorporated so as to insure that all of the exhaust portions being cooled will be completely encircled with cooling water even when low amounts of water are being circulated and a drain system is also provided so as to insure that the cooling jackets will be drained when the watercraft is removed from a body of water.

Abstract: Two embodiments of two cycle, crankcase compression engines wherein exhaust emissions are controlled by controlling the amount of scavenging air flow at low and mid ranges. The scavenging air flow is controlled by balance passages that interconnect at least two crankcase chambers of the engine and in which a control valve is provided. In one embodiment, the balance passage is positioned above the crankcase chambers and communicates with them through downwardly extending passages so as to preclude the likelihood of condensation of fuel or lubricant in the balance passages and to return any fuel or lubricant to the crankcase chambers.

Abstract: A motorcycle front wheel and disc brake assembly wherein the caliper of the disc brake assembly is supported directly by an axle carrier of the front wheel and is nested between the axle carrier and the front wheel. The caliper assembly is mounted centrally on the axle carrier so as to minimize the length of its supporting bracket and to reduce adverse effects on the suspension and steering of the front wheel.

Abstract: A fuel injection system for engines that employs a fuel injector that sprays into a chamber to which compressed air is delivered and which chamber communicates with the combustion chamber through a port that is opened and closed by the reciprocation of the piston if applied to a reciprocating engine. The source of compressed air may either be an air compressor or a crankcase chamber of the engine and the air compressor and/or crankcase chamber may also provide scavenging air for the engine. A variety of port arrangements are disclosed which include either single ports or a plurality of ports either circumferentially or axially spaced from each other and disposed between either the scavenge ports and exhaust ports or around a scavenge port or an exhaust port.

Abstract: A motorcycle having leading and trailing front and rear arm suspensions for the front and rear wheels. The motorcycle has a frame that is made up of a pair of side pieces that are integrally connected with each other with portions of the side pieces removeable for accessing and removal of the engine.