Abstract: A method of operating a vehicle is provided. The vehicle includes: an engine; a throttle operator moveable by a driver; a throttle valve regulating airflow to the engine; a continuously variable transmission (CVT) operatively connected to the engine; at least one ground engaging member including at least one of: a wheel and a track; a piston operatively connected to a driving pulley of the CVT for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley; and a control unit for controlling actuation of the piston and the piston force. The method includes: determining a driven pulley speed of a driven pulley of the CVT; detecting an uphill stand condition indicative of the vehicle being stopped on an uphill; responsive to the detection of the uphill stand condition, controlling the piston force based on the driven pulley speed.

Abstract: A method of operating a vehicle is provided. The vehicle includes: an engine; a throttle operator moveable by a driver; a throttle valve regulating airflow to the engine; a continuously variable transmission (CVT) operatively connected to the engine; at least one ground engaging member including at least one of: a wheel and a track; a piston operatively connected to a driving pulley of the CVT for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley; and a control unit for controlling actuation of the piston and the piston force. The method includes: determining a driven pulley speed of a driven pulley of the CVT; detecting an uphill stand condition indicative of the vehicle being stopped on an uphill; responsive to the detection of the uphill stand condition, controlling the piston force based on the driven pulley speed.

Abstract: A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission operatively connected to the engine has a driving pulley, a driven pulley, and a belt operatively connecting the driving and driven pulleys. A ground engaging member is operatively connected to the driven pulley. A piston is operatively connected to the driving pulley for applying a piston force thereto and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes detecting a stall condition indicative of the vehicle being stalled, and, responsive to the detection, setting the piston force to be zero.

Abstract: A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission operatively connected to the engine has a driving pulley, a driven pulley, and a belt operatively connecting the driving and driven pulleys. A ground engaging member is operatively connected to the driven pulley. A piston is operatively connected to the driving pulley for applying a piston force thereto and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes detecting a stall condition indicative of the vehicle being stalled, and, responsive to the detection, setting the piston force to be zero.

Abstract: A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission operatively connected to the engine has a driving pulley, a driven pulley, and a belt operatively connecting therebetween. A ground engaging member is operatively connected to the driven pulley. A piston is operatively connected to the driving pulley for applying a piston force thereto and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes determining at least one of the throttle operator and throttle valve position, detecting a parking/drive away condition indicative of one of a parking operation and a drive-away operation of the vehicle, and, responsive to the detection, actuating the piston and controlling the piston force based on the at least one of the throttle operator position and the throttle valve position.

Abstract: A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission is operatively connected to the engine and has a driving pulley, a driven pulley, and a belt operatively connecting therebetween. At least one ground engaging member is operatively connected to the driven pulley and includes at least one of a wheel and a track. A piston is operatively connected to the driving pulley for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes determining an engine speed, and controlling the piston force based on the engine speed.

Abstract: A method for cleaning an exhaust valve of a two-stroke internal combustion engine is provided. The method comprises: requesting an exhaust valve cleaning cycle if at least one of a first condition or a second condition is satisfied; initiating the exhaust valve cleaning cycle if at least one of a third condition or a fourth condition is satisfied; and aborting the exhaust valve cleaning cycle if at least one of the at least one of the third or fourth conditions is no longer satisfied. The first condition is a time elapsed since a previous cleaning cycle has been completed being greater than a predetermined time. The second condition is a rate of opening of the exhaust valve being less than predetermined rate. The third condition is a throttle valve being closed. The fourth condition is an engine speed being less than a predetermined engine speed.

Abstract: A method for cleaning an exhaust valve of a two-stroke internal combustion engine is provided. The method comprises: requesting an exhaust valve cleaning cycle if at least one of a first condition or a second condition is satisfied; initiating the exhaust valve cleaning cycle if at least one of a third condition or a fourth condition is satisfied; and aborting the exhaust valve cleaning cycle if at least one of the at least one of the third or fourth conditions is no longer satisfied. The first condition is a time elapsed since a previous cleaning cycle has been completed being greater than a predetermined time. The second condition is a rate of opening of the exhaust valve being less than predetermined rate. The third condition is a throttle valve being closed. The fourth condition is an engine speed being less than a predetermined engine speed.

Abstract: An exhaust valve assembly for a two-stroke internal combustion engine has a valve actuator, and a two-part valve having a primary and secondary valves defining first and second decompression passages respectively. The primary valve is operatively connected to the valve actuator. The primary valve is in first, second and third primary valve positions when the valve actuator is in first, second and third actuator positions respectively. The secondary valve is in a first secondary valve position when the valve actuator is in the first or the second actuator position and in a second secondary valve position when the valve actuator is in the third actuator position. The first and second valve decompression passages fluidly communicate with each other when the valve actuator is in the second actuator position, and are fluidly separate from each other when the valve actuator is the first or the third actuator position.

Abstract: A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission is operatively connected to the engine and has a driving pulley, a driven pulley, and a belt operatively connecting therebetween. At least one ground engaging member is operatively connected to the driven pulley and includes at least one of a wheel and a track. A piston is operatively connected to the driving pulley for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes determining an engine speed, and controlling the piston force based on the engine speed.

Abstract: A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission operatively connected to the engine has a driving pulley, a driven pulley, and a belt operatively connecting therebetween. A ground engaging member is operatively connected to the driven pulley. A piston is operatively connected to the driving pulley for applying a piston force thereto and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes determining at least one of the throttle operator and throttle valve position, detecting a parking/drive away condition indicative of one of a parking operation and a drive-away operation of the vehicle, and, responsive to the detection, actuating the piston and controlling the piston force based on the at least one of the throttle operator position and the throttle valve position.

Abstract: A method of operating a vehicle at different altitudes. The vehicle has an engine, a throttle valve and a throttle operator. A continuously variable transmission has a driving pulley connected to the engine, a driven pulley, and a belt operatively connecting therebetween. A ground engaging member is operatively connected to the driven pulley. A piston is connected to the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes determining an altitude and/or an atmospheric pressure, a driven pulley speed, and at least one of the throttle operator position and the throttle valve position. The piston is selectively actuated based on the altitude and/or the atmospheric pressure. The piston force is controlled based on the driven pulley speed, and at least one of: the throttle operator position and the throttle valve position. Vehicles and other methods of operation thereof are also disclosed.

Abstract: An exhaust valve assembly for a two-stroke internal combustion engine has a valve actuator, and a two-part valve having a primary and secondary valves defining first and second decompression passages respectively. The primary valve is operatively connected to the valve actuator. The primary valve is in first, second and third primary valve positions when the valve actuator is in first, second and third actuator positions respectively. The secondary valve is in a first secondary valve position when the valve actuator is in the first or the second actuator position and in a second secondary valve position when the valve actuator is in the third actuator position. The first and second valve decompression passages fluidly communicate with each other when the valve actuator is in the second actuator position, and are fluidly separate from each other when the valve actuator is the first or the third actuator position.

Abstract: A method of operating a vehicle at different altitudes. The vehicle has an engine, a throttle valve and a throttle operator. A continuously variable transmission has a driving pulley connected to the engine, a driven pulley, and a belt operatively connecting therebetween. A ground engaging member is operatively connected to the driven pulley. A piston is connected to the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes determining an altitude and/or an atmospheric pressure, a driven pulley speed, and at least one of the throttle operator position and the throttle valve position. The piston is selectively actuated based on the altitude and/or the atmospheric pressure. The piston force is controlled based on the driven pulley speed, and at least one of: the throttle operator position and the throttle valve position. Vehicles and other methods of operation thereof are also disclosed.

Abstract: An exhaust valve assembly for a two-stroke internal combustion engine has a valve actuator having a first pressure chamber and a second pressure chamber, and a valve operatively connected to the valve actuator. The first and second pressure chambers are adapted for selectively receiving one of a first pressure and a second pressure. The first pressure is higher than the second pressure. The valve actuator moves the valve between at least a first valve position and a second valve position. The valve actuator moves the valve to the first valve position when the first pressure is supplied to the first pressure chamber and the second pressure is supplied to the second pressure chamber. The valve actuator moves the valve to the second valve position when the second pressure is supplied to the first pressure chamber and the first pressure is supplied to the second pressure chamber.

Abstract: An exhaust valve assembly for a two-stroke internal combustion engine has a valve actuator having a first pressure chamber and a second pressure chamber, and a valve operatively connected to the valve actuator. The first and second pressure chambers are adapted for selectively receiving one of a first pressure and a second pressure. The first pressure is higher than the second pressure. The valve actuator moves the valve between at least a first valve position and a second valve position. The valve actuator moves the valve to the first valve position when the first pressure is supplied to the first pressure chamber and the second pressure is supplied to the second pressure chamber. The valve actuator moves the valve to the second valve position when the second pressure is supplied to the first pressure chamber and the first pressure is supplied to the second pressure chamber.