Abstract: The invention relates to a motorcycle engine arrangement which transmits a starting power to a crank shaft from a starter motor via a power transmission mechanism and a one-way clutch. The one-way clutch is installed at one end portion of the crank shaft, and a starter gear or a starter sprocket having a diameter smaller than an outer diameter of a clutch outer member is provided on the crank shaft portion further toward an outer side in an axial length direction of the crank shaft than the clutch outer member of the one-way clutch. Preferably, the clutch outer member is arranged further toward an outer side in the axial length direction of the crank shaft than a sprocket wheel for driving a cam or a gear for driving a cam provided at one end portion of the crank shaft.

Abstract: The invention relates to an engine for a motorcycle which transmits a starting power to a crank shaft from a starter motor via a power transmission mechanism and a one-way clutch. The one-way clutch is installed in one end portion of the crank shaft, and a starter gear or a starter sprocket having a smaller diameter than an outer diameter of a clutch outer member is provided on the crank shaft portion in an outer side in an axial length direction of the crank shaft rather than the clutch outer member of the one-way clutch. In preferable, the clutch outer member is arranged in an outer side in the axial length direction of the crank shaft rather than a sprocket wheel for driving a cam or a gear for driving a cam provided in one end portion of the crank shaft.

Abstract: A water-jet propulsion personal watercraft comprises a body including a hull and a deck covering the deck from above, a water jet pump disposed on a rear portion of the body and configured to propel the watercraft, an engine mounted forward relative to the water jet pump within the body and configured to drive the water jet pump, a propeller shaft configured to connect the engine to the water jet pump, a coupling mechanism disposed behind the engine and configured to connect an output shaft of the engine to the propeller shaft, and an air cleaner box disposed behind the engine and above the coupling mechanism within the body and configured to take in air for the engine from outside.

Abstract: A jet-propulsion watercraft comprises: an engine; an oil tank provided independently of the engine, for reserving engine oil; and a water jet pump driven by the engine, the water jet pump pressurizing and accelerating water taken in from outside of the watercraft and ejecting the water from the outlet port to propel the watercraft as a reaction of the ejecting water, and the muffler is provided behind the engine and on one of right and left sides of the watercraft and the oil tank is provided behind the engine and on the other side of the watercraft.

Abstract: A water-jet propulsion personal watercraft comprises a body including a hull and a deck covering the deck from above, a water jet pump disposed on a rear portion of the body and configured to propel the watercraft, an engine mounted forward relative to the water jet pump within the body and configured to drive the water jet pump, a propeller shaft configured to connect the engine to the water jet pump, a coupling mechanism disposed behind the engine and configured to connect an output shaft of the engine to the propeller shaft, and an air cleaner box disposed behind the engine and above the coupling mechanism within the body and configured to take in air for the engine from outside.

Abstract: A jet-propulsion watercraft comprises: an engine; an oil tank provided independently of the engine, for reserving engine oil; and a water jet pump driven by the engine, the water jet pump pressurizing and accelerating water taken in from outside of the watercraft and ejecting the water from the outlet port to propel the watercraft as a reaction of the ejecting water, and the muffler is provided behind the engine and on one of right and left sides of the watercraft and the oil tank is provided behind the engine and on the other side of the watercraft.

Abstract: A jet-propulsion watercraft comprises: an engine; an oil tank provided independently of the engine, for reserving engine oil; and a water jet pump driven by the engine, the water jet pump pressurizing and accelerating water taken in from outside of the watercraft and ejecting the water from the outlet port to propel the watercraft as a reaction of the ejecting water, and the muffler is provided behind the engine and on one of right and left sides of the watercraft and the oil tank is provided behind the engine and on the other side of the watercraft.