Yamaha Marine Kabushiki Kaisha

Sanshin Kogyo Kabushiki Kaisha

Jun Nakata

Yasuhiko Shibata

Toshiaki Sato

Hideaki Masui

Kazuhiro Okuzawa

Atsushi Nakamura

Katsuji Hirade

A water cooling system for an outboard motor can include a casing that is configured to be submerged in water at a lower part thereof and to support an internal combustion engine on an upper part thereof. The system can have an exhaust passage that is formed in the casing and through which exhaust gas from the internal combustion engine is inducted from the upper part of the casing toward the lower part, a portion of the exhaust passage between an upstream-side passage and a downstream-side passage being configured as an expansion chamber. Also provided is a cooling water passage extending along the exhaust passage and a drain port that permits water to be discharged into the downstream-side passage after passing through the cooling water passage.

Water cooling device for outboard motor

A casing of an outboard motor can be formed with an upper casing, a lower casing, and an extension casing interposed between the upper casing and the lower casing. Water guiding passages, which can be formed with jacket sections or the like, can extend along both inner side surfaces of the extension casing. The water guiding passages can communicate with a space. Water that leaks from a cooling water pump in the space is allowed to flow through the water guiding passages so as to be used as cooling water. A cooling water inlet of each jacket section can be made at a bottom end of a partition, while the cooling water outlet of each jacket section can be made at a top end of a partition. A bottom of each jacket section can be formed with a bottom closure member.

Outboard motor for small watercraft

An exhaust system that reduces noise generated by exhaust gases is provided. The exhaust system includes a drive unit that supports an internal combustion engine. An exhaust guide forms an upper portion of the case. An oil pan is attached to a lower surface of the exhaust guide. An exhaust passage leads exhaust gas of the internal combustion engine from an upper side to a lower side of the case, and discharges the exhaust gas from the lower side into a body of water. A branch passage extends from the exhaust passage at an intermediate portion thereof. The branch passage is configured for discharging the exhaust gas inside the exhaust passage into ambient air, and includes an expansion chamber at its intermediate portion. The expansion chamber is partially defined by the exhaust guide and partially defined by the oil pan.

Exhaust system for internal combustion engine of outboard motor

An exhaust system for an outboard motor includes an internal combustion engine. An intermediate member supports the engine. A housing unit depends from the intermediate member. An exhaust system guides exhaust gases from the engine. The exhaust system includes a main exhaust passage and an idle exhaust passage. The main exhaust passage discharges the exhaust gases that are produced above idle to the body of water through the housing unit. The idle exhaust passage discharges the exhaust gases that are produced during idle to the atmosphere. The intermediate member defines a portion of the main exhaust passage and a portion of the idle exhaust passage. The intermediate member forms a recessed area in the main exhaust passage portion. The idle exhaust passage communicates with the main exhaust passage portion at the recessed area.

Exhaust system for outboard motor

An outboard motor includes a housing unit that forms an outer wall exposed outside. An engine is disposed above the housing unit. The engine defines a water jacket. A water transfer system is arranged to introduce water from outside of the housing unit to deliver the water to the water jacket and to discharge the water to a location out of the housing unit. The water transfer system includes first and second water passages defined within the housing unit. The first water passage communicates with the water jacket. The second water passage does not communicate with the water jacket. The water transfer system delivers a portion of the water to the second water passage upstream of the water jacket. The second water passage extends next to the outer wall. The first water passage is spaced apart from the outer wall by the second water passage.

Cooling arrangement for outboard motor

An outboard motor includes a housing unit and an engine disposed above the housing unit. The engine defines a first exhaust passage to discharge exhaust gases from the engine and a lubricant passage through which lubricant flows. A lubricant reservoir member is disposed below the engine within the housing unit to define a lubricant reservoir therein. The lubricant passage communicates with the lubricant reservoir. A second exhaust passage, which can be defined on an outer surface of the lubricant reservoir member, extends along the height of the lubricant reservoir. The housing unit defines third and fourth exhaust passages. The third exhaust passage is arranged between the first and second exhaust passages. The fourth exhaust passage is arranged downstream of the second exhaust passage. The housing unit defines an exhaust discharge port at an end of the fourth exhaust passage. The exhaust discharge port communicates with the atmosphere.

Idle exhaust system for outboard motor

A shaft coupling for an outboard motor includes an improved construction that can be held under a good lubricative condition. The outboard motor includes an engine. An engine body defines a first aperture through which a crankshaft extends and is journaled. A recessed portion of the crankshaft defines inner spline grooves. A support member that supports the engine body has a second aperture. A driveshaft extends through the second aperture toward the recessed portion. The driveshaft has a tip portion defining outer spline grooves that are coupled with the inner spline grooves. A first seal member is disposed between an outer surface of the output shaft and an inner surface of the first aperture. A second seal member is disposed between an outer surface of the driveshaft and an inner surface the second aperture. The engine body, the support member, the output shaft, the driveshaft and the first and second seal members together define a lubricant chamber to enclose lubricant.

Shaft coupling for outboard motor

A cooling system for an outboard motor includes an improved construction that can inhibit a housing unit of the outboard motor from absorbing heat that causes discoloring of the unit. The outboard motor includes a power head that has an engine. The housing unit depends from the power head. An exhaust conduit is arranged to discharge exhaust gases from the engine. At least a portion of the exhaust conduit extends through the housing unit. A cooling system is arranged to cool at least the portion of the exhaust conduit by coolant. The cooling system includes an inner coolant pool surrounding the portion of the exhaust conduit and an outer coolant pool surrounding the inner coolant pool. The cooling system supplies the coolant to the inner and outer pools. The coolant supplied to the outer pool is cooler than the coolant supplied to the inner pool.

Cooling system for outboard motor

An internal combustion engine includes at least one combustion chamber formed by at least a first member and a second member that moves relative to the first member. The second member is coupled to an output shaft such that movement of the second member causes the output shaft to rotate. The engine also includes a cooling system configured to circulate coolant into thermal communication with at least a portion of the engine. An induction system is also included for providing a fuel/air charge to the combustion chamber. The induction system includes a charge former configured to form the fuel/air charge and a mounting plate that is attached to the carburetor. The mounting plate includes a first coolant passage that is in communication with the cooling system.

Heat exchange support plate for engine carburetors

An outboard motor has an exhaust pipe assembly extending through a driveshaft housing. The exhaust pipe is separated into an upstream exhaust pipe and a downstream exhaust pipe which are formed separately from each other. The upstream exhaust pipe depends into the driveshaft housing and has a lower end connected to a pipe support member. An upper end of the downstream exhaust pipe connects to the pipe support member in a manner to communicate with the upstream exhaust pipe. The downstream pipe depends through an opening in a bottom wall of the driveshaft housing, and a mount at the lower end of the pipe is connected to the driveshaft housing in order to secure the pipe in place. The upper end of the downstream exhaust pipe is fit into the pipe support member without the use of fasteners. In this configuration, the downstream exhaust pipe can be removed independently of the upstream exhaust pipe, and can be drawn downwardly through the opening during removal. This enables the downstream exhaust pipe to be easily and quickly replaced.

Growing community of inventors

Shizuoka, Japan

Jun Nakata