Abstract: An internal combustion engine performs an ignition timing control by an electronic control in accordance with a pulse signal from a pulser. The pulser generates a plurality of the pulser signals per one rotation of the internal combustion engine. An ignition timing control system calculates a reduction amount of a rotational speed of the internal combustion engine based on a plurality of the pulse signals immediately before performing an ignition in the internal combustion engine to determine whether the reduction amount produces ignition combustion kickback and performs a hard ignition or an ignition at an angle which is delayed more than the hard ignition.

Abstract: An internal combustion engine performs an ignition timing control by an electronic control in accordance with a pulse signal from a pulser. The pulser generates a plurality of the pulser signals per one rotation of the internal combustion engine. An ignition timing control system calculates a reduction amount of a rotational speed of the internal combustion engine based on a plurality of the pulse signals immediately before performing an ignition in the internal combustion engine to determine whether the reduction amount produces ignition combustion ketching and performs a hard ignition or an ignition at an angle which is delayed more than the hard ignition.

Abstract: An engine decompressor includes a decompressor pin provided through a pin hole on the surface of a valve cam, a decompressor pin operating shaft in an oil passage provided in a valve cam shaft of the valve cam for vertically moving the decompressor pin by its rotation, a fly weight rotatable by rotation of the valve cam shaft so as to rotate the decompressor pin operating shaft, and a thrust receiving plate separate from the fly weight for restricting the axial movement of the decompressor pin operating shaft in the oil passage. The engine decompressor is capable of operating a decompressor mechanism normally even if the lubricating oil increases in pressure.

Abstract: An engine decompressor includes a decompressor pin provided through a pin hole on the surface of a valve cam, a decompressor pin operating shaft in an oil passage provided in a valve cam shaft of the valve cam for vertically moving the decompressor pin by its rotation, a fly weight rotatable by rotation of the valve cam shaft so as to rotate the decompressor pin operating shaft, and a thrust receiving plate separate from the fly weight for restricting the axial movement of the decompressor pin operating shaft in the oil passage. The engine decompressor is capable of operating a decompressor mechanism normally even if the lubricating oil increases in pressure.

Abstract: A shift assisting mechanism for assisting the shifting of a dog clutch of a marine transmission by reducing the engine speed. The requirement for engine speed reduction is sensed by a pressure sensitive conductive rubber type pressure sensing switch contained within the interconnection between the operator and the dog clutch.

Abstract: A shift assisting mechanism for a marine outboard transmission that includes a sensing device comprised of a pair of relatively movable levers with pressure responsive switches being effective to transmit movement between the levers and provide a shift controlling signal when the resistance to movement exceeds a predetermined value.

Abstract: An ignition control system for an internal combustion engine of the type employed to power a watercraft wherein the engine speed is reduced upon the sensing of an abnormal engine condition. When the engine speed is reduced, the spark timing is also retarded to avoid backfiring in the exhaust system unless the engine conditions indicate that the exhaust gas temperatures might become too high under this retarded condition.

Abstract: An inboard/outboard drive arrangement and specifically an improved exhaust joint therefor wherein at least one of the rigid conduits of the exhaust system is provided with a projection to engage and restrain a hose clamp which may be released and inadvertently dropped so as to prevent loss of the hose clamp into an inaccessible area.

Abstract: A marine outboard drive incorporating a power operated tilt and trim arrangement and an arrangement for increasing the speed of the engine when the power operated tilt and trim device is operated so as to avoid speed changes during tilt and trim operation. The speed increasing is achieved by altering the spark advance curve and is only done when the propulsion device is driving the watercraft and when the engine generator is generating a predetermined power output.

Abstract: Several embodiments of spark timing control for spark ignited internal combustion engines that improve running under certain adverse conditions. Arrangements are disclosed for reducing the speed of the engine in response to certain abnormal conditions, such as shifting of an associated transmission. The speed is reduced by interrupting the spark of the engine. In accordance with the disclosed embodiments, uneven running and stalling is avoided by advancing the spark if the engine speed falls below a predetermined engine speed.