An two-stroke internal combustion engine includes a cooling circuit having at least one passageway on the exhaust side of the engine for cooling the exhaust side of the engine and at least one passageway on the intake side of the engine for cooling at least a portion of the intake side of the cylinder. The engine also includes at least one cooling channel traversing the engine located in the vicinity of one of the bearings supporting the crankshaft for cooling the bearings.