Two-stroke internal combustion engine

A two-stroke internal combustion engine (100), comprising:

• a cylinder (135) having a pre-set central axis (B),
• a piston (145) slidably coupled to the cylinder (135) and adapted to divide the interior volume of the cylinder (135) into two distinct chambers;
• a combustion chamber (150) and a pumping chamber (155),
• an intake duct (160) communicating with the pumping chamber (155),
• an exhaust duct (170) communicating with the combustion chamber (150), and
• at least one scavenging duct (180) adapted to place the pumping chamber (155) in communication with the combustion chamber (150),
• wherein said scavenging duct (180) comprises a terminal portion (190) leading to the combustion chamber (150) which extends with configuration diverging from an inlet section (200) up to an outlet section (205) obtained on a lateral surface of the cylinder (135), and
• wherein the projection of the terminal portion (190) of the scavenging duct (180) on a median plane (M) containing the axis (B) of the cylinder (135) is fully contained in the projection of the outlet section (205) on the same median plane (M), said median plane (M) being a symmetry plane of the exhaust duct (170),
• wherein the cross-section of the terminal portion (190) of the scavenging duct (180), carried out according to a section plane orthogonal to the central axis (B) of the cylinder (135), is substantially trapezoidal-shaped wherein said cross-section has a side substantially orthogonal to the median plane (M).