1974 Yamaha TZ750A Racing Motorcycle
Frame no. 409-00356
Engine no. 409-81
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. Yamahas new F750 contender drew on the Hamamatsu firms 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 TZ350s 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. Despite the TZ750 moniker, displacement remained at 694cc until October 1974 when the second batch of TZ750Bs was released featuring a full-size (747cc) engine.
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. 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 Daytonas bumpy banking will ever forget the sight. Recent research suggests that Yamaha eventually made a little under 800 of these spectacular motorcycles, which today are highly sought after by collectors and classic racers alike.
This TZ750A originally belonged to Danish rider Borje Nielsen, who raced it in period in the FIM Cup (photographs on file). It racing career over, the machine stood idle for 34 years before being restored by Nielsens mechanic in 2009/2010, since when it has been used for a parade in Portugal. The engine was rebuilt again earlier this year and needs running in. Work carried out included reconditioning the crankshafts, con-rods, big-ends and main bearings; re-plating one cylinder; and renewing the countershaft and clutch. We are advised that the rear brake is inoperative and that the machine will need to be carefully checked and re-commissioned prior to further use. The engine has not been started since the rebuild and there is no oil in the gearbox. Representing a wonderful opportunity to acquire one of the most charismatic racing motorcycles of modern times, this outstandingly original TZ750 comes with a quantity of used spares.
- The frame number is: -900356
The engine number is 409-01