The enhanced two-stroke engine (1) comprises a crankcase (2), a cylinder (3) provided with an exhaust port (6), a series of transfer ports (7) communicating with the crankcase (2), the cylinder (3) further comprises at least an air inlet port (8) positione...

The adjustable gearbox (8) for vehicles with constant clearance from the ground (4) according to the invention is provided for the driving wheel or wheels (5, 6) of a vehicle, the box (8) comprises a reducing unit (8a) with three axes (11a, 13a, 33'; 11a, ...