Valve system for two-stroke engine

A two-stroke engine comprising:

• a cylinder having a cylinder axis, the cylinder including a combustion chamber and a fluid port formed in a sidewall of the cylinder, the fluid port including at least one of an intake port and an exhaust port;
• a piston configured to move within the cylinder along the cylinder axis during a power cycle between a first position in which a volume of the combustion chamber is at a maximum, and a second position in which the volume of the combustion chamber is at a minimum;
• a valve member moveable along the cylinder axis and disposed in the cylinder between the piston and the sidewall, the valve member configured to be moved between an open position and a closed position, wherein the valve member covers the fluid port in the closed position;
• and
• an actuator configured to move the valve member in coordination with movement of the piston during a power cycle, so that the valve member is in the closed position as the piston traverses the fluid port.

A method of operating a two-stroke engine comprising:

• providing a fuel mixture to a cylinder of the two-stroke engine, the cylinder having a cylinder axis, the cylinder including a combustion chamber and a fluid port formed in a sidewall of the cylinder, the fluid port including at least one of an intake port and an exhaust port, the cylinder enclosing a piston configured to move within the cylinder between a first position in which a volume of the combustion chamber is at a maximum, and a second position in which the volume of the combustion chamber is at a minimum;
• moving the piston along the cylinder axis between the first position and the second position during a power cycle;
• and
• moving a valve member along the cylinder axis in coordination with the piston, the valve member disposed in the cylinder between the piston and the sidewall and moveable between an open position and a closed position, wherein the valve member covers the fluid port in the closed position, and wherein the valve member is controlled so that the valve member is in the closed position as the piston traverses the fluid port.