The mainstay of 250cc and 350cc class racing at national and international level for many years, the twin-cylinder two-stroke Yamaha well deserved the title of 'privateer's friend'. Following its successful adoption for the 1972 works twins, water cooling first appeared on Yamaha's over-the-counter racers with the introduction of the TZ range in 1973. Power output increased only marginally over that of the preceding air-cooled TD/TR models, but reliability was much improved. Over the succeeding decade the TZ engine was updated with reed-valve induction, exhaust power valves, separate cylinders and a backwards-rotating crankshaft, but the layout always remained that of a parallel twin. On the chassis side, discs replaced the original drum brakes, a 'lowboy' frame was introduced, and an aluminium swinging arm adopted. With Yamaha concentrating their resources on developing their 500 Grand Prix bike and the new TZ750, the smaller TZs remained unchanged through 1974 (TZ250/350B) and 1975 (TZ250/350C). From the mid-1980s onwards, a succession of more radical changes would see the TZ fundamentally altered. This beautiful TZ350B had already been restored when it was purchased by the Museum. It should be noted that the crankcases are unstamped apart from the (correct) 'R5' prefix, indicating that they were supplied new as spares. It should also be noted that it the engine believed to be of 250cc capacity. There are no documents with this Lot.