Yamaha Hatsudoki Kabushiki Kaisha

Mamoru Atsuumi

Takashi Ashida

Yorio Futakuchi

Manabu Kai

Hiroyuki Kosugi

Hirotsugu Oga

Mitsuo Ito

In a starting device of an engine, a starter clutch is provided with an outer race that rotates with a rotor (starter member), and a cam interposed between the outer race and a starter gear. A through hole is formed in the rotor so as to face the outer race axially. A stepped section is provided between a radially outer portion of the outer race, the portion facing a radially outer edge of the through hole, and a radially inner portion of the outer race. The stepped section causes the radially outer portion to be thinner than the radially inner portion. The starting device is capable of ensuring a cooling capability of a stator coil even though the rigidity of the outer race is increased.

Starting device of engine

A snowmobile includes an improved internal combustion engine. The engine comprises a crankcase, a crankshaft rotatably journaled within the crankcase, a cylinder block assembly extending from the crankcase, and a cylinder head assembly connected to an end of the cylinder block opposite the crankcase. A cam drive mechanism including at least one camshaft is rotatably journaled within the cylinder head assembly. A transmission is coupled to the crankshaft to transmit power from the engine to the drive assembly. The cam drive mechanism is connected to the crankshaft at a first end portion of the crankshaft. The transmission is connected to the crankshaft at a second end portion of the crankshaft opposite the first end portion.

Internal combustion engine for a snowmobile

A coolant pump for an engine includes a pump case main body and a pump drive shaft journaled therein. The pump drive shaft has a plurality of blades mounted thereon and is rotatable about a pump drive shaft axis. The coolant pump also includes a partition member and a lid. The partition member and the pump case main body define a pump chamber configured to house the blades. The partition member also defines a pump chamber inlet port. A fluid inlet chamber is defined by the partition member and the lid. The fluid inlet chamber provides fluid communication between a fluid inlet port and the pump chamber inlet port.

Coolant pump for snowmobile engine

A snowmobile has an engine with a compact arrangement that includes a crankshaft, an output shaft, and an auxiliary shaft. The crankshaft extends along a first axis, the output shaft extends along a second axis, and the auxiliary shaft extends along a third axis. Two of the first axis, the second axis, and the third axis are disposed in a common plane. The other of the first axis, the second axis, and the third axis is offset from the common plane.

Snowmobile

A snowmobile has an internal combustion engine that includes a lubrication system. The lubrication system includes a lubricant pump unit mounted in a crankcase chamber of the engine, a lubricant cooler, and a lubricant filter. The lubricant pump unit is mounted at a location offset from an axis about which the crankshaft rotates. The lubricant pump unit also has a lubricant pump that is rotatable about a lubricant pump axis. At least one of the lubricant cooler and the lubricant filter is positioned on the same side of the engine as the lubricant pump unit.

Lubrication system for snowmobile engine

A land vehicle, such as a snowmobile, comprises a frame with an engine mounted to the frame. The frame is supported by at least one steerable member. The steerable member is controlled by a rider with a steering handle. The engine comprises a decompression mechanism to lower the compression ratio during starting, for instance. The decompression mechanism is actuated by an actuator mounted outside of an engine compartment in which the engine is mounted. The actuator can be a steering handle mounted lever. The decompression mechanism can be mounted on a cylinder head of the engine. In one arrangement that allows the mechanism to control compression in multiple cylinders, the mechanism can be mounted between adjacent exhaust ports of adjacent cylinders.

Decompression arrangement for land vehicle

A land vehicle includes an improved construction that can space a steering linkage from the terrain even though an engine for the vehicle has an oil pan positioned at a lower portion of the engine and the steering linkage passes below the engine. The land vehicle includes a drive unit that depends from a body frame and abuts the terrain. The body frame carries the engine. The oil pan is positioned generally at a bottom of the engine and lubricant oil temporarily accumulates in the oil pan. A steering assembly is connected to the body frame for steering movement. The steering assembly includes a pair of skis and a steering linkage extending through the body frame and arranged to steer the skis. The steering linkage and the oil pan, at least in part, are generally horizontally juxtaposed with each other.

Steering and lubrication system component arrangement for land vehicles

An engine having a crank case splitted into upper and lower crank cases, and including a crank shaft and a transmission drive shaft disposed on the split plane between the upper crank case and the lower crank case and a transmission main shaft carried by either one of the upper or lower crank case. The length and the size of the engine can be reduced by the arrangement according to the invention, and a starter motor, a transmission drum and balancers can be arranged efficiently to save space required for mounting the engine.

Engine for vehicle

A number of embodiments of internal combustion engines incorporating toothed belt driven overhead camshafts. In each embodiment, the driving belt is contained within a protective case that is separated from the engine by an air gap for insulation and a cooling fan driven by the camshaft circulates cooling air through the belt case. All embodiments employ air inlets for the belt case that are disposed in sheltered areas so as to prevent contaminants from being drawn into the belt case. In addition, a generator is contained within the belt case for protection.

Belt driven camshaft mechanism for internal combustion engine

Two embodiments of motorcycles having improved exhaust systems. In each embodiment, the motorcycle includes a V-type engine and the exhaust system provides substantially equal length exhaust pipes that merge into a common exhaust outlet and which are disposed beneath the clutch and on the opposite side of the engine from the generator. In addition, one embodiment discloses an oil filter that is disposed above the clutch so as to be protected from the heat of the exhaust pipes by the clutch.

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Shizuoka, Japan

Mamoru Atsuumi