Abstract: A fuel supply cut control device comprising an electronic control unit for controlling the injecting operation of a fuel injector. When the throttle valve is closed to the idling position under an operating state where the engine speed is higher than the cut speed, the fuel injection of the fuel injector is stopped. After this, when the engine speed is reduced below the resume speed, the injecting operation of the fuel injector is started. When the vehicle speed is high, the cut speed and the resume speed are low, and when the vehicle speed is low, the cut speed and the resume speed are high.

Abstract: An internal combustion engine comprises a first raised portion formed on the inner wall of the cylinder head, a second raised portion formed on the top face of the piston at a position opposite to the first raised portion with respect to the axis of the piston, and a third raised portion formed on the inner wall of the cylinder head above the second raised portion. A first flat squish area is formed between the flat peripheral top face of the piston and the flat bottom face of the first raised portion. A second spherical shell shape squish area is formed between the spherical bottom wall of the third raised portion and the spherical rear face of the second raised portion.

Abstract: An internal combustion engine comprises a first raised portion formed on the inner wall of the cylinder head, a second raised portion formed on the top face of the piston at a position opposite to the first raised portion with respect to the axis of the piston, and a third raised portion formed on the inner wall of the cylinder head above the second raised portion. A first flat squish area is formed between the flat peripheral top face of the piston and the flat bottom face of the first raised portion. A second spherical shell shape squish area is formed between the spherical bottom wall of the third raised portion and the spherical rear face of the second raised portion. A recess is formed on the top face of the combustion chamber and arranged on an extension of the second squish area. The spark plug is arranged in the recess.

Abstract: An internal combustion engine comprises a first raised portion formed on the inner wall of the cylinder head, a second raised portion formed on the top face of the piston at a position opposite to the first raised portion with respect to the axis of the piston, and a third raised portion formed on the inner wall of the cylinder head above the second raised portion. A first flat squish area is formed between the flat peripheral top face of the piston and the flat bottom face of the first raised portion. A second spherical shell shape squish area is formed between the spherical bottom wall of the third raised portion and the spherical rear face of the second raised portion. The third raised portion has a steeply inclined side wall extending upwards from the ridge of the second raised portion. A depression having a vertically extending peripheral wall is formed in the central portion of the top face of the piston. The peripheral wall is aligned with the vertically extending side wall of the first raised portion.

Abstract: An internal combustion engine comprises a first raised portion formed on the inner wall of the cylinder head, a second raised portion formed on the top face of the piston at a position opposite to the first raised portion with respect to the axis of the piston, and a third raised portion formed on the inner wall of the cylinder head above the second raised portion. A first flat squish area is formed between the flat peripheral top face of the piston and the flat bottom face of the first raised portion. A second spherical shell shape squish area is formed between the spherical bottom wall of the third raised portion and the spherical rear face of the second raised portion. The surface areas of the first squish area and the second squish area which are located near said exhaust valve are larger than those of the first squish area and the second squish area which are located near the intake valve.