Sanshin Kogyo Kabushiki Kaisha

Yamaha Hatsudoki Kabushiki Kaisha

Shigeo Okumura

Kenichi Handa

Shinya Atsumi

Motoi Tobinaga

Kyoji Hakamata

Koushiro Inaba

Koshiro Inaba

A pressure sensitive valve device is provided for use in a cooling system for the engine of a marine propulsion unit. The pressure sensitive valve device of the invention communicates with the coolant line pressure of an engine cooling jacket at both a coolant input port region of the cooling jacket and a coolant output port region of the cooling jacket. When the difference in pressure between these two regions exceeds a predetermined limit the pressure sensitive valve device opens, thereby permitting coolant to pass therethrough. The cooling system also employs a temperature sensitive valve device positioned in parallel with the pressure sensitive valve device. The temperature sensitive valve device is operative to control coolant flow within the engine in the low RPM operation range, while the pressure sensitive valve device becomes operative to control coolant flow in the high RPM operation range, where the thermal load of the engine is great. Thus, sufficient coolant flow may be achieved throughout the entire engine operating range.

Water cooling system for a marine propulsion unit

An exhaust supercharging arrangement for a two-cycle internal combustion engine having groups of cylinders each of which merge into respective exhaust manifolds. The exhaust manifolds communicate with each other and the firing order is such that the one cylinder of one group is on its scavenge cycle when another cylinder of the other group is on its exhaust cycle for minimizing the torque and heating loading on the engine.

Exhaust system for two-stroke engine

A device for controlling the ignition of an internal combustion engine to eliminate knocking and including a knocking sensor and method for detecting knocking. The knocking sensor is positioned in proximity to one cylinder of the engine and a reference signal is generated when another of the cylinders fires. This reference signal is compared with the output of the knocking sensor to determine a knocking condition.

Knocking sensor for internal combustion engine

An ignition control system for an internal combustion engine which includes a microcomputer which operates to control the ignition timing in response to engine speed and engine temperature signals individually and in preselected combinations with an engine throttle or air flow signal during predetermined engine running conditions. These predetermined running conditions include low speed, warm up, overheat, cruising, and overspeed engine running conditions. The ignition control system is also capable of detecting and responding to abnormal combustion running conditions and setting an optimum spark advance during the starting of the engine.

Ignition control system for an internal combustion engine

An outboard motor having a V-type crankcase compression internal combustion engine wherein the exhaust ports of each bank are disposed on the same side of the cylinder bore and on a side so as to minimize thermal loading of the skirt of the piston and the problems attended therewith.

Two-stroke multi-cylinder engine

Two embodiments of ignition timing mechanism wherein a timing curve is generated in response to the position of the throttle valve. In each embodiment the timing is advanced on progressive opening of the throttle valve until a predetermined maximum advance is obtained at a position less than wide-open throttle. The timing is then retarded from the maximum advanced position as the throttle valve is continued to open to its wide-open throttle position. In each embodiment the timing is retarded beyond the maximum advanced position to a predetermined advanced position prior to fully wide-open throttle position and this advance is held during the remainder of opening of the throttle valve.

Growing community of inventors

Hamamatsu, Japan

Shigeo Okumura