Abstract: A power pack for a vehicle selected from a group of different vehicles is disclosed. The power pack includes an internal combustion engine and a continuously variable transmission (CVT) operatively connected to the engine. The CVT includes: a drive pulley operatively connected to a crankshaft of the engine, the drive pulley being rotatable about a drive pulley axis; a driven pulley rotatable about a driven pulley axis; a belt connecting the drive pulley to the driven pulley; and a housing at least partly enclosing the drive pulley, the driven pulley and the belt. The power pack also includes a sub-transmission selected from a group of different sub-transmissions depending on the selected vehicle. The selected sub-transmission is mounted to the housing of the CVT. The housing of the CVT is configured to mount any sub-transmission of the group of different sub-transmissions. A method for assembling a power pack is also provided.

Abstract: An engine assembly for a vehicle includes an internal combustion engine and an exhaust system. The exhaust system includes a catalytic converter, a main muffler, a hydrocarbon trap, a pre-muffler disposed upstream from the main muffler and the hydrocarbon trap, and an exhaust path valve. The exhaust path valve is movable between first and second exhaust path positions. The exhaust path valve obstructs a second exhaust path in the first exhaust path position such that exhaust gas flows from an exhaust port of an engine cylinder to the catalytic converter to the main muffler and to the atmosphere. The exhaust path valve obstructs a first exhaust path in the second exhaust path position such that exhaust gas flows from the exhaust port of the engine cylinder to the catalytic converter to the hydrocarbon trap and to the atmosphere.

Abstract: A method of operating an exhaust valve of a two-stroke internal combustion engine is disclosed. The engine has a cylinder and a piston movably disposed within the cylinder. The cylinder defines at least one exhaust port for discharging exhaust fluid from the cylinder. The exhaust valve is configured to cyclically obstruct the exhaust port. The method includes: rotating the exhaust valve in a first direction for clearing the exhaust port before the piston uncovers the exhaust port during a downstroke of the piston, the first direction being opposite a direction of rotation of a crankshaft of the engine; and rotating the exhaust valve in the first direction for at least partially closing the exhaust port before the piston fully covers the exhaust port during an upstroke of the piston, said rotating of the exhaust valve relative to the rotation of the crankshaft at least partially counterbalancing the crankshaft.

Abstract: An engine assembly for a vehicle includes an internal combustion engine operating on a two-stroke engine cycle. A compressor is in fluid communication with an intake port of at least one cylinder of the engine to pump air into the engine. An exhaust pipe is in fluid communication with an exhaust port of the at least one cylinder. The exhaust pipe has an inlet and an outlet defining a length of the exhaust pipe therebetween. A diameter of the exhaust pipe increases along a portion of the length of the exhaust pipe in a flow direction of the exhaust pipe. The diameter of the exhaust pipe does not decrease along the length of the exhaust pipe in the flow direction of the exhaust pipe.

Abstract: A power pack for a vehicle selected from a group of different vehicles is disclosed. The power pack includes an internal combustion engine and a continuously variable transmission (CVT) operatively connected to the engine. The CVT includes: a drive pulley operatively connected to a crankshaft of the engine, the drive pulley being rotatable about a drive pulley axis; a driven pulley rotatable about a driven pulley axis; a belt connecting the drive pulley to the driven pulley; and a housing at least partly enclosing the drive pulley, the driven pulley and the belt. The power pack also includes a sub-transmission selected from a group of different sub-transmissions depending on the selected vehicle. The selected sub-transmission is mounted to the housing of the CVT. The housing of the CVT is configured to mount any sub-transmission of the group of different sub-transmissions. A method for assembling a power pack is also provided.

Abstract: An engine assembly for a vehicle includes an internal combustion engine operating on a two-stroke engine cycle. A compressor is in fluid communication with an intake port of at least one cylinder of the engine to pump air into the engine. An exhaust pipe is in fluid communication with an exhaust port of the at least one cylinder. The exhaust pipe has an inlet and an outlet defining a length of the exhaust pipe therebetween. A diameter of the exhaust pipe increases along a portion of the length of the exhaust pipe in a flow direction of the exhaust pipe. The diameter of the exhaust pipe does not decrease along the length of the exhaust pipe in the flow direction of the exhaust pipe.

Abstract: A method of operating an exhaust valve of a two-stroke internal combustion engine is disclosed. The engine has a cylinder and a piston movably disposed within the cylinder. The cylinder defines at least one exhaust port for discharging exhaust fluid from the cylinder. The exhaust valve is configured to cyclically obstruct the exhaust port. The method includes: rotating the exhaust valve in a first direction for clearing the exhaust port before the piston uncovers the exhaust port during a downstroke of the piston, the first direction being opposite a direction of rotation of a crankshaft of the engine; and rotating the exhaust valve in the first direction for at least partially closing the exhaust port before the piston fully covers the exhaust port during an upstroke of the piston, said rotating of the exhaust valve relative to the rotation of the crankshaft at least partially counterbalancing the crankshaft.

Abstract: A two-stroke internal combustion engine has a crankshaft disposed at least in part in a crankcase, and a cylinder block connected to the crankcase and defining a cylinder. The cylinder defines at least one exhaust port for discharging exhaust fluid. A piston is movably disposed within the cylinder and is operatively connected to the crankshaft. The piston is movable along a cylinder axis in a reciprocating motion including an upstroke and a downstroke. An exhaust valve assembly is operatively connected to and rotates with the crankshaft. The exhaust valve assembly has a shaft rotatably supported by the cylinder block and a valve configured to cyclically obstruct the exhaust port. The valve is operable to move clear of the exhaust port before the piston uncovers the exhaust port during its downstroke, and at least partially close the exhaust port before the piston fully covers the exhaust port during its upstroke.

Abstract: A two-stroke internal combustion engine has a crankshaft disposed at least in part in a crankcase, and a cylinder block connected to the crankcase and defining a cylinder. The cylinder defines at least one exhaust port for discharging exhaust fluid. A piston is movably disposed within the cylinder and is operatively connected to the crankshaft. The piston is movable along a cylinder axis in a reciprocating motion including an upstroke and a downstroke. An exhaust valve assembly is operatively connected to and rotates with the crankshaft. The exhaust valve assembly has a shaft rotatably supported by the cylinder block and a valve configured to cyclically obstruct the exhaust port. The valve is operable to move clear of the exhaust port before the piston uncovers the exhaust port during its downstroke, and at least partially close the exhaust port before the piston fully covers the exhaust port during its upstroke.

Abstract: An exhaust assembly for a vehicle is disclosed, which includes a resonator including an inlet adapted for fluidly connecting to an exhaust manifold, and a closed end at an end of the resonator opposite the inlet; and a turbocharger passage extending from the resonator between the exhaust manifold and the closed end, the turbocharger passage defining an outlet. An exhaust system, a power pack, and the vehicle including the exhaust assembly are further disclosed.

Abstract: An exhaust assembly for a vehicle is disclosed, which includes a resonator including an inlet adapted for fluidly connecting to an exhaust manifold, and a closed end at an end of the resonator opposite the inlet; and a turbocharger passage extending from the resonator between the exhaust manifold and the closed end, the turbocharger passage defining an outlet. An exhaust system, a power pack, and the vehicle including the exhaust assembly are further disclosed.