Patent ID: 7213544

Claim:
An internal combustion engine comprising: a crankcase; a crankshaft disposed in the crankcase; a cylinder block connected to the crankcase, the cylinder block having a cylinder disposed therein; a main exhaust port in fluid communication with the cylinder, the main exhaust port having a cross-sectional area; an auxiliary exhaust port in fluid communication with the cylinder, the auxiliary exhaust port having a cross-sectional area smaller than the cross-sectional area of the main exhaust port; a piston movably disposed within the cylinder and being operatively connected to the crankshaft; an exhaust valve assembly, the exhaust valve assembly comprising: a main exhaust valve for at least partially closing the main exhaust port; an auxiliary exhaust valve for at least partially closing the auxiliary exhaust port, the auxiliary exhaust valve being separate from and movably connected to the main exhaust valve; an actuator for actuating the main exhaust valve and the auxiliary exhaust valve; the actuator being connected to the main exhaust valve; the auxiliary exhaust valve being connected to the actuator via the main exhaust valve; and the engine operating on a two-stroke principle.