c.1979 Yamaha TZ750 Racing Motorcycle
Frame no. 409-200366
Engine no. 409-200203
Although Formula 750 had been intended as a class for modified production road bikes, Yamaha managed to get its TZ750 racer homologated provided that at least 200 were built. Yamaha's new F750 contender drew on the Hamamatsu firm's tried-and-tested two-stroke technology, its engine looking like two TZ350 twins on a common crankcase, although in actual fact few components were shared. The TZ350's 64x54mm bore/stroke dimensions were retained, giving the first TZ750 model (retrospectively re-designated TZ750A) a capacity of 694cc. Together with the contemporary YZR500 Grand Prix machine, the TZ750 was the first Yamaha road-racing motorcycle to feature reed valve induction, a measure considered necessary to broaden what would otherwise have been an unacceptably peaky power delivery. The TZ750 engine was built in unit with a six-speed gearbox and went into an entirely new, twin-shock frame that looked reminiscent of the Rob North-designed chassis used by the racing BSA-Triumph 750 triples.
The pre-production TZ750 prototype was tested in Japan towards the end of the 1973 by Australian World Champion Kel Carruthers, who on his retirement at the season's end assumed the role of managing Yamaha's works team in the USA. Works riders Gene Romero and Kenny Roberts tested the first production examples prior to the season-opening Daytona 200, but the honour of securing the TZ750's debut race win at the Florida track went to Giacomo Agostini, newly arrived from MV Agusta. Roberts finished 2nd, slowed by a cracked exhaust, while Romero came in 6th.
Despite the 'TZ750' moniker, displacement remained at 700cc until October 1974 when the second batch of TZ750Bs was released featuring a full-size (750cc) engine, For 1976, the works TZ750s used the YZR500 Grand Prix racer's lightweight frame and a more powerful engine ported to Kel Carruthers' specifications. Designated 'OW31' by the factory, these works bikes provided the blueprint for the customer TZ750D for 1977 although the production models did not fully match the works specification, lacking most of the latter's magnesium and titanium components, and were only marginally lighter than the twin-shock TZ750C. In its ultimate, OW31-type configuration, the TZ750 continued essentially unchanged until production of the final 'F' variant ceased in 1979.
Like the smaller TZ twins, the TZ750 was an enormous success, providing privateers the world over with the means to compete against the factory teams in Formula 750. With its spindly tubular frame, relatively narrow tyres, 130bhp maximum power output and a wheelbase shorter than a current Moto GP bike, the TZ750 was certainly a handful. Packed grids of near-identical bikes made for close racing, and no-one who witnessed these demanding machines being wrestled around UK short circuits, the Isle of Man TT course or Daytona's bumpy banking will ever forget the sight. Various authorities have suggested a manufacturing total for the TZ750 at somewhere in the 500-600 range, though more recent research suggests that Yamaha eventually made a little under 800. Today these spectacular machines are highly sought after by collectors and classic racers alike.
Representing a wonderful opportunity to acquire one of the most charismatic racing motorcycles of modern times, this late example is fitted with an earlier engine, which according to an accompanying letter from retired French rider Hubert Rigal, powered the TZ750 he rode in the 1977 Formula 750 Championship. The current owner purchased the machine in France in 1987 and it is hoped that further information concerning its racing history will have come to light by time of sale. A seat unit, two front brake callipers and one rear calliper are included in the sale.