Abstract: An electrode apparatus (15) is provided for mounting an anode (17) and reference electrode (19) of a cathodic protection system on an outboard drive unit (10). The apparatus includes an insulating housing (20) on which the anode (17) and reference electrode (19) are mounted and a copper shield (30) mounted between the anode (17) and electrode (19) to allow them to be mounted in close proximity to each other. The shield (30) is electrically connected to the device to be protected and serves to match the electrical field potential at the reference electrode (19) to that of a point on the outboard drive unit (10) remote from the housing (20).

Abstract: A hydraulic system for trimming and tilting an outboard propulsion unit (10) includes both trim piston-cylinder units (22, 23) and a trim-tilt piston-cylinder unit (17). The flow of hydraulic fluid from the reversible pump (49) is controlled by a spool valve (26). A pressure relief valve (71) is mounted in the spool (50) to maintain pressure on one side of the spool (50) when the pump (49) is turned off to rapidly close the return valve (56) and prevent further movement of the piston-cylinder units.

Abstract: A four cylinder, two-cycle engine (10) has an exhaust system formed in a die-cast cylinder block. The exhaust system includes four legs (25) connected to the exhaust ports (23) of the cylinders (12). The upper two legs join together, as do the lower two legs to form two exhaust branches (26) connected by an exhaust trunk (27). An exhaust outlet passage (28) connected to the trunk (27) to provide an outlet for exhaust gases. The exhaust system is formed to lie in a plane on the exhaust side of the cylinder block (16).

Abstract: A recoil starter mechanism (10) mounted in axial alignment with the flywheel (12) of an internal combustion engine has a drive plate (16) with clutch teeth (34) which moves axially when rotated to engage clutch teeth (17) on the flywheel and rotate the flywheel (12) to start the engine. The drive plate (16) is driven axially and rotationally by ramps (30) on the starter pulley (14) when the starter rope (24) is pulled. A brake plate (18) frictionally engaging the starter housing (13) has arms (37) engaging the drive plate to resist rotation of the drive plate (16), thereby forcing the drive plate to move axially as the starter pulley (14) is rotated.

Abstract: A temperature compensated flow sensor (10) for monitoring oil flow to a two-cycle engine includes a magnetic flow sensing body (26) mounted in a flow sensing bore (21). The position of the flow sensing body is detected by a Hall switch (42) to provide an electrical output indicating a flow or a no flow condition. The flow sensing body (26) is biased toward the Hall switch (42) by a spring (27) and a spring follower (31) controls the spring rate as a function of temperature. A thermal power element (35) moves the spring follower as a function of temperature to compensate for the change of oil viscosity with temperature.

Abstract: The tilt mechanism (10) for a marine propulsion unit has a swivel bracket (14) pivotally attached to a transom bracket (11). A trim pin (20) is carried by a trim pin carrier (24) which is pivotally attached to the swivel bracket (14). The trim pin (20) travels in cam slots (19) which define two connected cam loops and acts as a ratchet with notches (21, 22, 23) in the cam slots (19) to establish trim and tilt positions for the propulsion unit. The two cam loops allow the propulsion unit to be returned to the uppermost position without dropping to the lowest position first. A moveable return cam (38) in the lower loop allows the operator to select the lowest trim position to which the unit will return.

Abstract: The invention provides a modular ignition system using a separate ignition module (16) for each engine cylinder. The modules (16) can be arranged for use with engines having differing numbers of cylinders.Each module (16) includes a main capacitor (22) to be charged by the engine's alternator (11). The main capacitor (22) is discharged through a main silicon controlled rectifier (23) into an ignition transformer (28) to provide a high voltage pulse to fire a spark plug (15). A pilot capacitor (26) is also charged by the alternator (11) to provide power to a pilot SCR (36). The pilot SCR (36) has its gate connected to a trigger winding (14) in the alternator (11) to discharge the pilot capacitor (26) into the gate of the main SCR (23) to fire the spark plug (15).The pilot capacitor (26) is also connected to the cathode of the main SCR (23).

Abstract: A two-cycle engine having an oil pump (19) driven by the engine crankshaft (11) to supply lubricant to the carburetor (12) has an alarm system to warn of an interruption of the oil pump drive. The alarm system has a signal processor (23) connected to activate an alarm (27) should signals from an oil pump rotation sensor (26) be interrupted, if a level switch (28) in the oil tank (20) indicates a low oil level, or should a signal from the ignition system (14) be interrupted. The signal processor (23) is also connected to briefly activate the alarm (27) when the engine is started to provide a test of the alarm system.

Abstract: The invention provides a wiring assembly (10) for connecting a spark plug (21) to a high voltage source (16). A shell (23) is provided over the flexible boot (20) to prevent damage to the clip (17) on removal and attachment to the spark plug terminal (13). A tie strap (33) is provided around the spark plug lead (11) to prevent the plug connector (14) from being removed from its terminal (15) without disengaging the boot (31).

Abstract: The invention provides a flow sensor (10) for providing an electrical output indicating a no flow condition, an intermediate flow rate, and a high flow rate and is particularly suited for sensing the flow of lubricant to a two-cycle engine. The flow sensor (10) includes a metallic reed valve member (22) which contacts a valve seat (28) to provide a no flow signal or an adjustable contact member (31) to provide a high flow signal. The reed valve member (22) contacts neither the valve seat (28) nor the contact member (31) to indicate an intermediate flow rate.

Abstract: A connector for attaching a central core wire (11) of a flexible cable to a control element (13) has a cable guide (15) attached to the core wire (11). A pivot pin (22) extending through a bore in the cable guide (15) is attached to the control element (13) and has an annular groove (23) in one end. A locking body (24) has a cylindrical section (25) reciprocally mounted on the cable guide (15) and an arm (27) extending forward to engage the groove (23) in the pivot pin (22). A notch (29) at the end of the arm (27) snaps around the pivot pin (22) to hold it in place.

Abstract: The invention provides a connecting rod assembly (10) for use in linking a piston (11) to a crankshaft and particularly provides a means for precisely aligning and attaching the connecting rod cap (15) to the connecting rod (12). The connecting rod assembly (10) uses bolts (18) extending through the cap (15) and engaging female screw threads (22) in the rod (12) to retain the cap (15) in place. Truncated female screw threads (23) are provided in the cap (15) to engage and distort the threads on the bolt (18) as the bolt (18) is tightened to align the rod (12) and cap (15) and to lock the bolt (18) in place.

Abstract: The invention provides charging control circuitry (20) for a capacitor discharge ignition system (10) having power capacitors (21) connected to be discharged by main electronic switches such as SCR's (23) into ignition transformers (24) to sequentially fire the engine's spark plugs (16). The charging control circuits (20) each include a charging SCR (26) to limit charging current flow to the main capacitor (21), unless a discharge pulse into the ignition transformer (24) has occurred in the recent past. Thus if a short circuit in either the main capacitor (21) or main SCR (23) in one of the ignition circuits (19) prevents that ignition circuit from properly functioning, the charging SCR (26) will limit the flow of charging current to the defective circuit and allow the other ignition circuit (19) to receive charging current. The gate of the charging SCR (26) is controlled by an amplified signal from a memory capacitor (28) which is charged by the discharge pulse from the corresponding ignition circuit (19).

Abstract: The invention provides an alternator driven by an engine crankshaft (11). A stator mounted on the engine (10) includes circumferentially spaced power coils (19) lying in the plane of and radially inward of the power magnets (20) mounted on the engine flywheel (12). Ignition coils (18) are mounted circumferentially spaced from the power magnets (20), but axially offset therefrom to couple with the fringe flux of the power magnets, thus allowing a high output from the power coils (19) without overloading the ignition coils (18).

Abstract: The invention provides a mounting apparatus for outboard trolling motors. A linkage having equal length bars is pivotally mounted to the outboard motor swivel bracket (14) and to a mounting bracket (13) to constrain the outboard motor (10) to rotate 90 degrees between its operating position and its retracted position as the linkage arms (15, 19) rotate approximately 180 degrees. A latch (24) secures the swivel bracket (14) to the mounting bracket (13) in the operating position.

Abstract: The invention provides an energy regulating system for regulating the electrical energy generated by the coil (11) of an alternator and used to charge a battery (12). A full wave bridge rectifier circuit (13) supplies direct current to the battery. A comparator (25) is connected to the positive terminal of the battery to provide an output when the battery charge is below the desired level. The output of the comparator is connected through a photo coupler (33) to control the main SCR (18) and thus control the charging current to the battery.

Abstract: The invention provides an induction system for supplying air-fuel mixture to a two-cycle, crankcase compression engine (10). A single carburetor barrel (18) supplies mixture to each crankcase compartment (15) through a reed valve assembly having a plurality of reed valve members (29) arranged in a circular pattern. An axially symmetric passage leads from the carburetors (17) to the reed valves and has a generally conical flow modifying body (40) projecting forwardly from the reed valves.

Abstract: The invention provides an outboard motor tilt mechanism for releasably supporting the propulsion unit in several elevated positions. A swivel bracket (16) is pivotally supported on a transom bracket (11) to provide tilting movement. A support arm (17) pivotally attached to the transom bracket (11) has an elongated slot slidably engaging a locking pin (21) fixed to the swivel bracket (16). A control handle (25) controls the tension on spring (28) to either permit or prevent engagement of the locking pin (21) with locking recesses (22, 23, 24) in the support arm (17).

Abstract: The invention provides a connecting rod bolt (10) for maintaining precise alignment of the connecting rod (11) with the connecting rod cap (14). The connecting rod bolt (10) has a section (31) knurled to a diameter larger than the bores (30) in the rod and cap with which it mates. Upon insertion of the bolt (10) into the bore (30) the bolt will be precisely matched to the bore.

Abstract: A hydraulic trim-tilt system 15 for an outboard motor 10 includes a hydraulic trim-tilt piston-cylinder unit 16 pivotally connected to both the transom bracket 11 and the swivel bracket 12. Hydraulic trim piston-cylinder units 22 are mounted in the transom bracket 11. A pilot operated check valve 43 mounted in the piston 38 of one of the trim piston-cylinder units 22 serves to limit the maximum pressure in the system when the trim piston-cylinder units 22 have reached the end of their stroke.