KZ2 is a kart racing class using 125 cc water-cooled two-stroke engines yielding about 52 hp (39 kW). The engines are equipped with a 6-speed gearbox. Z2 is the second fastest of the KZ karting racing categories, and technical regulations are similar to faster KZ1 except that in KZ2 the gearbox must be "hand-operated and exclusively mechanical without a servo system", as well as the use of medium tires. Both the engine and chassis must be approved by the CIK-FIA racing governing commission. The class is open to drivers aged 15 years and up with the minimum weight being 175 kg, this includes the kart and driver.