The Yamaha TZR is a series of two-stroke, single-cylinder sport bikes produced by the Japanese motorcycle manufacturer Yamaha from 1984 to 2008. The TZR series was based on the popular TZ series of street bikes, but was designed to be higher-performance. The bikes featured Yamaha's innovative Power Valve System (YPVS), which opened exhaust ports at different times during the power stroke to optimize the engine's power delivery. Additionally, the TZR featured Yamaha's Autolube oil injection system, allowing for easier starting and longer engine life. The TZR was popular in both road and race competition, and several versions were offered, including race-spec versions such as the TZR250SP and TZR250R.