125cc 4-stroke. Starts on the first kick and also has a convenient push-button electric start ignition system. It is in great condition and has had several recent updates/improvements including: a fresh set of Artrax TG5 off road tires, new heavy-duty tubes, and a Motion Pro clutch cable. Just had a fresh oil change and is ready to ride. This bike is easy to maintain and a lot of fun to ride for both experienced riders and beginners.