Honda Motor Co., Ltd.

Honda Giken Kabushiki Kaisha

Michio Izumi

Yosuke Hoi

Kazuhiko Tomoda

Yoshitsugu Gokan

Hisashi Matsuo

Hitoshi Yokotani

Hiroyuki Makita

Masataka Eguchi

Hiroyuki Kaga

Kazuhiro Shimazaki

Kazunori Okada

An internal combustion engine for a small planing boat for reducing the lateral width of an oil pan in conformity to the configuration of the bottom while securing the filtering surface area of an oil strainer. In addition, a vertical width of the oil pan is maintained to be small to thereby lower the total height of the internal combustion engine. In an internal combustion engine for a small planing boat, an oil pan is provided at the bottom portion of the internal combustion engine with an oil passage for communicating with an oil pump being formed inside the oil pan. A vertical wall of the oil passage is partially cut away to form communication openings each communicating between the inside and outside of the oil passage with the oil strainers being interposed in the communication openings substantially vertically to divide the oil passage into inside and outside.

Internal combustion engine for small planing boat

To provide an inner shim that is unlikely to fall off from a spring retainer even when an anomalous operation of a valve occurs. A spring retainer fixed to the upper end portion of a valve shaft has a shim-attachment hole. An inner shim is fitted into the shim-attachment hole. The bottom face of the inner shim is in contact with the upper end portion of the valve shaft, and the top face of the inner shim is positioned below the upper edge of the shim-attachment hole. A tappet is disposed above the spring retainer, and is allowed to move freely in the axial direction of the valve shaft. A shim-holding projection sticks out from the under face of the tappet, and extends downward. The projection enters, from above, the inside of the shim-attachment hole, and is in contact with the top face of the inner shim.

Valve mechanism of engine

The use of an oil cooler in an internal combustion engine for a personal watercraft is controlled, whereby excessive cooling of the engine during warmup with cold water operation is avoided, and dilution of oil is substantially prevented. The internal combustion engine includes a bypass oil path connecting respective oil paths upstream and downstream of the oil cooler. The bypass oil path permits oil to be selectively detoured around the oil cooler. An oil thermostat is provided in the upstream oil path for selectively opening either a path to the oil cooler or the bypass oil path, and the oil thermostat is operable to switch the flow of oil therebetween. The oil thermostat opens the bypass oil path when the temperature of the oil is below a predetermined temperature, and directs oil to the oil cooler when the temperature of the oil is equal to or exceeds a predetermined temperature.

Internal combustion engine having an improved oil cooling structure, and personal watercraft incorporating same

To provide a system for lubricating an engine for a personal watercraft, which is capable of simplifying an oil piping structure. An oil pump driven by a crankshaft of an engine and a relief valve for controlling a discharge pressure of the oil pump are provided in an oil tank provided on an extension of the crankshaft of the engine. Suction/discharge passages and the like for the oil pump are provided integrally with a tank main body. An oil filter in communication with the oil pump is provided in an upper portion of the oil tank, and communication passages for the oil filter are provided integrally with the oil tank. The oil filter is aligned with an opening of a deck. The tank main body covers drive chambers for accessories such as an ACG, a balancer shaft, and a starter motor of the engine.

System for lubricating engine for personal watercraft

Growing community of inventors

Saitama, Japan

Michio Izumi