Abstract: A vacuum system testing tool for checking a vacuum system for leaks or restrictions includes a hollow housing defining a central chamber, with a calibrated air flow orifice, a connector for connecting the tool to the system to create a pressure drop across the air flow orifice, and a device for measuring the pressure drop.

Abstract: An improved diver's boarding ladder and dive door for a boat having a dive opening. The boarding ladder is positionable between a boarding position and a storage position without having to be removed and stored. In the boarding position, the dive opening is opened and the boarding ladder extends below the waterline to assist swimmers and divers in boarding the boat from the water. In the storage position, the dive door closes the dive opening and the boarding ladder is stored out of the way inside the boat's hull in an inverted position. The boarding ladder is secured in the dive opening with a hinge that runs along the entire length of the bottom of the dive opening and acts as a chafe plate to prevent damage to the boat's hull from dive equipment.

Abstract: Disclosed herein is an engine assembly comprising an engine block, a crankshaft rotatably mounted in the engine block and having an end and an axis, a flywheel fixed to the end of the crankshaft and including a first flux plate including a plurality of angularly spaced pole pieces extending axially away from the end of the crankshaft, a second flux plate axially spaced from the first flux plate and including a plurality of angularly spaced pole pieces extending toward the first flux plate and being spaced from and inter-digitated between the pole pieces of the first flux plate, a core extending axially between the first and second flux plates, a coil located in surrounding relation to the core and radially inwardly of the pole pieces and between the first and second flux plates, and a stator coil stationarily mounted on the engine block in outward, radially adjacent relation to the pole pieces, and slip ring means mounted on the flywheel and on the engine block and connected to the coil for energization there

Abstract: An engine having an engine block defining at least two cylinders having respective cylinder heads. Pistons are reciprocal within respective ones of the cylinders. The cylinders have respective fuel inlet ports and exhaust ports and two of said cylinders have an idle relief port disposed between their respective exhaust port and head ends. The idle relief ports of the cylinders are interconnected by a passageway for providing communication between the idle relief ports of said at least two cylinders. This has been found to provide reduced pull start resistance, reduced engine vibration during idle, and significantly reduced horsepower loss over a wide operating range which horsepower loss is normally associated with idle prior art relief structures which vent directly from idle relief ports to atmosphere.

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: Disclosed herein is a marine propeller comprising a marine propeller comprising an inner bushing adapted to be mounted on a propeller shaft for common rotation therewith and having an axis and an outer surface, a resilient bushing fixed to said outer surface of said inner bushing and having a cylindrical outer surface extending, when relaxed, at a first radial distance from said bushing axis, an outer bushing having an inner bore defined by a lobular surface having a maximum radial distance from said bushing axis less than said first radial distance, receiving said resilient bushing in a compressed condition and with said lobular surface in continuous circumferentially extending engagement with said outer surface of said resilient bushing, and comprising a series of inwardly concave cylindrical segments, and a series of blades extending radially outwardly from said outer bushing.

Abstract: A variable integration based ignition circuit for an internal combustion engine recognizes predetermined engine conditions and modifies or limits ignition advance when the predetermined conditions are violated to protect the engine. The ignition circuit includes an ignition triggering circuit which causes the engine ignition to ignite in response to ignition pulse signals. A pulse generator generates and outputs signal pulses when the sensor detects positions of the crankshaft. A speed detector calculates the rotational speed of the flywheel based on the signal pulses. Ignition pulse signals are retarded when the rotational speed exceeds a predetermined level to limit rotational speed and protect the engine. The ignition circuit may also limit ignition pulse signals in response to low oil pressure.

Abstract: Disclosed herein is an air silencer comprising a main body including a first member including a first wall partially defining a first plenum area, a second wall partially defining a second plenum area, and a third wall connecting the first and second walls, a second member including a first wall which partially defines a plenum area cooperating with the first plenum area of the first member to define a first plenum chamber, a second wall which partially defines a plenum area cooperating with the second plenum area of the first member to define a second plenum chamber, and a third wall which connects the first and second walls of the second member and is located in spaced relation to the third wall of the first member to define therebetween a narrow passage between the first and second plenum chambers.

Abstract: Disclosed herein is an outboard motor comprising means adapted for connection to a boat transom and including a swivel bracket having a kingpin bore, a propulsion unit comprising a power head including an internal combustion engine, a lower unit fixed to the power head and including a drive shaft having a vertically extending axis, being driven by the engine, and adapted to drive a propeller, a forwardly facing surface located on the propulsion unit in forwardly spaced relation to the drive shaft axis, a kingpin extending in the kingpin bore and including an upper end, a steering arm connected to the upper end of the kingpin for rotation in common with the kingpin, and vibration isolation means connecting the steering arm and the propulsion unit and located above the upper end of the kingpin and forwardly of the forwardly facing surface on the propulsion unit.

Abstract: Disclosed herein is an outboard motor including an engine block assembly comprising an engine block, a crankshaft rotatably supported by the engine block and including an upper part above the engine block, a flywheel fixed on the upper part of the crankshaft, a recoil starter above the flywheel, a crankshaft timing gear fixed on the upper part of the crankshaft, a camshaft rotatably supported by the engine block and including an upper part above the engine block, a camshaft timing gear fixed to the upper part of the camshaft and located above the engine block, a timing belt extending between and around the crankshaft timing gear and the camshaft timing gear, and a one-piece cover mounted on the engine block and enclosing the flywheel, the recoil starter, the camshaft timing gear, and the timing belt, and a cowling enclosing the engine block assembly.

Abstract: A monolithic metallic drive shaft for a marine propulsion device is disclosed which is resistant to corrosion. The drive shaft comprises proximal and distal end portions, each of which has a predetermined surface hardness. The surface hardness of one of the proximal and distal end portions is greater than the surface hardness of the other of the proximal and distal end portions.

Abstract: Disclosed herein is a one piece drive shaft housing comprising a casting including an outer surface having an upper end surface, a lower end surface, and an endless side surface extending between the upper and lower end surfaces, an internal cavity extending between the upper and lower end surfaces and adapted to receive a drive shaft and a clutch operated linkage, an internal exhaust gas passage extending between the upper and lower end surfaces and located in spaced relation to the cavity, an internal coolant supply passage extending between the upper and lower end surfaces, an internal idle exhaust passage including a series of expansion chambers and extending between the upper end surface and the endless side surface, and an internal coolant drainage passage extending between the upper and lower end surfaces in heat exchanging relation to the exhaust gas passage.

Abstract: Disclosed herein is an outboard motor including a fore and aft center plane and comprising a powerhead assembly including a two stroke internal combustion engine including a cylinder block including a port side, a starboard side, a plurality of vertically aligned cylinders in a single bank, which cylinders each include an axis extending at an angle to said center plane and to one of said port and starboard sides, and an exhaust port on the other of said port and starboard sides, and an exhaust gas passage including a main portion extending vertically adjacent said center plane, and a like plurality of elbow portions connecting said exhaust ports to said main portion, which elbow portions include any one change in direction.

Abstract: Disclosed herein is a carburetor including a member defining an air induction passage including a downstream portion, an upstream portion, and a venturi located between the downstream portion and the upstream portion, a member defining a fuel chamber, a fuel well located in the air induction passage defining member, extending in the fuel chamber, and communicating with the fuel chamber, a high speed nozzle located in the fuel well and communicating with the venturi, and an enrichment fuel pump including a cover fixed to the fuel chamber defining member, a diaphragm located between the cover and the fuel chamber defining member and defining a fuel pumping chamber and a variable pressure chamber, a duct communicating between the variable pressure chamber and the downstream portion of the air induction passage downstream of the throttle valve, an inlet conduit communicating between the fuel chamber and the fuel pumping chamber and including an inlet check valve permitting in-flow into the fuel pumping chamber an

Abstract: A marine propulsion unit is disclosed which has an exteriorly accessible clean-out capability. The unit has an impeller housing located outside of the transom of a marine craft in which the unit is installed, which impeller housing has a separable portion that permits access to the main passage including the impeller when separated. The design also permits insertion of a hose connected fitting for backflushing the cooling system of the power head of the unit.

Abstract: Apparatus for moving a reciprocating object, such as a spring biased poppet valve, between a rest and a second position. The apparatus includes two solenoids, each of which has a core, with one of the solenoids having a larger core and imparting greater force than the other. The solenoids are mounted in line with one another so that the core of one solenoid is adapted to contract the core of the other, with the latter being adapted to contact the object. A first solenoid provides a driving force to the object to move it in opposition to a biasing force and the second solenoid holds the object in its moved position when the first solenoid is de-energized. When the core of the first solenoid is in its rest position, it is out of contact with the core of the second solenoid and this enables the biasing force of the object to rapidly move to its rest position upon de-energization of the second solenoid.

Abstract: The invention provides a fiberglass recreational boat comprising a hull piece having a cockpit with a floor, a deck piece having an integral aft seat with the aft seat being arcuately shaped, and a gunwale. The hull piece and the deck piece are mated at the gunwale with the aft seat being suspended above the cockpit floor.

Abstract: Disclosed herein is a marine propulsion water pump including a casing defining a water passage including an inlet, an outlet, and an intermediate portion between the inlet and the outlet, a first impeller located in the intermediate portion of the casing, a second impeller located in the intermediate portion of the casing and rearwardly of the first impeller, a first shaft drivingly connected to the first impeller, extending forwardly therefrom, and having a hollow interior, a second shaft drivingly connected to the second impeller, extending in the hollow interior of the first shaft and forwardly therefrom, and gearing for counter-rotating the first and second shafts.

Abstract: Disclosed herein is a four stroke engine breather comprising a camcase cover including an outer surface partially defining a camcase cover chamber including first and second sub-chambers communicating with each other and a sump sub-chamber, an inlet passage through the camcase cover and communicating with the camcase cover chamber for conveying an air/oil mist from the camcase to the camcase cover chamber, a restricted oil drainage passage through the camcase cover and communicating with the sump sub-chamber for conveying oil from the sump sub-chamber to the camcase, an oil drainage aperture in the camcase cover and communicating between the sump sub-chamber and one of the first and second sub-chambers, a plate engaging the camcase cover to further define the camcase cover chamber and including an aperture communicating through the plate with one of the first and second sub-chamber in the camcase cover chamber, a reed valve fixed relative to the plate and including a valve portion movable between positions cl