2015 Gas Gas EC Racing 300 E, Just in, very nice ride with digital read out! - Technological leap forward in the Racing range 2015. Definitely the 2-stroke range is receiving most of the latest news prior to the release of the 2015 models, with changes in the depths of its heart: the engine. Thus, the new externally adjustable centrifugal exhaust valve system gives outside access to the centrifugal spring preload, so as to provide a fast and simple way to customize engine performance to the tastes of each client.