Yamaha Hatsudoki Kabushiki Kaisha

Keiichi Harada

Takeshi Ito

Yu Motoyama

Takafumi Fukuda

Masaki Ohsako

Yasushi Goro

An exhauster for a motorcycle with a reduced number of components and reduced cost in a structure containing a variable passage area valve. An exhaust chamber has a box-shaped chamber main body, a plurality of expansion chambers a through c formed by sectioning the interior of the chamber main body with partitioning walls, and communication passages for connecting the expansion chambers a through c with one another. A variable passage area valve that controls passage area is contained in the communication passage.

Exhauster for motorcycle and motorcycle including exhauster

An exhaust system for a motorcycle provides enhanced steering stability and improved function for purifying exhaust gas. Front exhaust pipes connected with front cylinders of a V-type engine are joined to a front part of an exhaust chamber. Rear exhaust pipes connected with rear cylinders of the engine are joined to an upper part of the exhaust chamber. Exhaust gases discharged from both the front and rear exhaust pipes are unified within the exhaust chamber, and a catalyst is disposed in the vicinity of the unifying section. The length of the rear exhaust pipes is shorter than the length of the front exhaust pipes. High-temperature exhaust gas is introduced to the catalyst contained within the exhaust chamber via the rear exhaust pipes.

Exhaust system of motorcycle and motorcycle including exhaust system

A direct lubricating system for a machine such as a cycle internal combustion engine wherein the lubricant is delivered directly to the sliding surfaces of the engine to be lubricated. A less viscous fluid such as fuel is mixed with the lubricant so as to ensure good distribution and the desired viscosity.

Lubrication system for two-stroke engine

A number of embodiments of combustion chambers for direct cylinder injected engines wherein the combustion chamber has a recess surrounded by a squish area. The fuel injector is disposed so that it will spray into the recess against the wall rather than toward the squish area. Alternate spark plug locations are disclosed.

Combustion chamber for injected engine

A fuel injection system for a two cycle engine having main fuel injectors that inject directly into the engine combustion chambers and a sub or auxiliary fuel injector that injects into the induction system only under high load conditions to effect better piston cooling. Once the sub fuel injector begin to inject, then the amount of fuel per cycle injected by the main fuel injectors is decreased. The sub injector injects into a common manifold for a multiple cylinder engine and injects only one per crankshaft revolution.

Growing community of inventors

Iwata, Japan

Keiichi Harada