A two-cycle engine that includes a high pressure fuel pump that pressurizes fuel to produce pressurized fuel and pumps the pressurized fuel from a fuel controller to a fuel injector. The fuel injector injects the pressurized fuel into a cylinder. A high pressure air pump pressurizes air to produce pressurized air and pumps the pressurized air from an air controller to an air injector. The air injector injects the pressurized air into the cylinder.

In the present invention, an internal combustion engine is provided with an in-cylinder fuel injection valve and a secondary air supply device and is formed so as to make possible first catalyst warming control and second catalyst warming control that promote the raising of the temperature of an exhaust gas purification catalyst. The first catalyst warming control comprises control to inject fuel from the in-cylinder fuel injection valve during the compression stroke to form a stratified state, and control to greatly delay ignition timing. The second catalyst warming control comprises control to supply secondary air to an engine exhaust gas passage. The internal combustion engine executes the first catalyst warming control after startup and, after the first catalyst warming control is executed, carries out control (third catalyst warming control) to execute the first catalyst warming control and the second catalyst warming control simultaneously.

In the present invention, an internal combustion engine is provided with an in-cylinder fuel injection valve and a secondary air supply device and is formed so as to make possible first catalyst warming control and second catalyst warming control that promote the raising of the temperature of an exhaust gas purification catalyst. The first catalyst warming control comprises control to inject fuel from the in-cylinder fuel injection valve during the compression stroke to form a stratified state, and control to greatly delay ignition timing. The second catalyst warming control comprises control to supply secondary air to an engine exhaust gas passage. The internal combustion engine executes the first catalyst warming control after startup and, after the first catalyst warming control is executed, carries out control (third catalyst warming control) to execute the first catalyst warming control and the second catalyst warming control simultaneously.

An internal combustion engine (10) includes at least one cylinder (12) having a piston, and a cylinder head containing an inlet duct (3) incorporating an inlet valve 1 to allow flow in only one direction and an exhaust duct incorporating no mechanical flow restricting device and at least one chamber valve (2) through which both inlet and exhaust fluids pass from the ducts (3,4) into and out of the cylinder (12), and a combustion chamber (6) in the cylinder (12) that allows the chamber valve (2) to be significantly open when the piston (5) is at top dead centre enabling a transfer of fluid, fluid flow pressure and pressure waves between the cylinder, and the inlet (3) and exhaust ducts (4).