The brand new engine Polini THOR 250 is distinguished by being provided with liquid cooling, securing an extraordinarily consistent performance and higher performance characteristics at every rpm. With its small size and extremely compact, the new THOR 250 has an extraordinary weight ratio power. The cylinder is cast in aluminum alloy and provides greater thermal stability. The barrel is characterized Nickel-silicon coating; It is particularly resistant to wear and abrasion, enhancing the sliding of the piston. The piston is gravity cast in light alloy with high silicon content. It allows to contain the thermal expansion, reducing the coupling play. The design of the piston crown is specific to optimize the compression ratio. The advanced technology and the high performance of the new THOR 250, allow a better feeling of driving by making more powerful, dynamic, responsive and sensitive to the flight, in addition to also ensure greater stability. Like its predecessor to 200 cc., Also THOR 250 is provided with a balancer; feature that cancels the vibrations guaranteeing driving comfort never experienced in flight and a longer life to the motor. Polini has addressed a great attention to safety.The fact THOR 250 adopts the centrifugal clutch in oil bath totally mechanically reduced with helical teeth. The counter rotating weight significantly decrease the annoying pair of reversal for added comfort in flight. The manual start is facilitated thanks to the flash device starter that speeds and simplifies the movement. Polini Thor engine 250 is distinguished by many other advanced solutions, including the preferred closed loop system for the fuel recovery during transport and the output arrangement 12 V for any uses electrical. As an option it is available with electric start. The engine has already confirmed its outstanding performance characteristics when tested on the dyno by technicians Polini. The new engine THOR 250 is suitable for such diverse applications including tandem paracarrelli, micro-lights, small axes three cars, motor gliders, microlight.