Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/1497874
Martin Wimmer as teammate. The YZF750 Magee used was an evolution of the FZ750 that was being raced around the world with a different swing- arm, a highly tuned engine and a new version of the Deltabox chassis, which made its produc- tion debut on the 1985 Yamaha TZR250 two-stroke roadbike and was originally a development of the 1982 Yamaha YZR500 Kenny Roberts used in 500GP. Mick Doohan also used a fac - tory Yamaha YZF750 Formula One machine to take victory in the TBC Road Race at Sugo and the Mt Fuji Super Sprint event in Japan in 1988. So the basis for the 1989 Yamaha FZR750R OW01 had been set. The OW01 cost the equivalent of a small apartment in 1989. You had to part with over $16K to get one, and that was for the standard bike. If you wanted the race kit that was available as an aftermarket purchase, which included a non-road-legal carburetor kit, exhaust muffler, ignition system, alternative fork springs, heavier clutch springs, ECU and wiring harness, race camshafts, some new gaskets, spark plugs and sockets, you could easily add another $12- 15K to the deal. However, a small ace in the OW01's deck over the RC30 was that it came pretty spec'd up as a standard bike. The RC30 had a massive list of add-ons via the race kit that needed to be fitted if you wanted a real race weapon, whereas the Yamaha was pretty quick straight out of the box. Australian Simon Thomas was crew chief to double WorldSBK and 1994 AMA Su - perbike Champion Troy Corser during his 1992 Australian Su- perbike season on the Yamaha OW01 and remembers it well. "It was a real production race bike," Thomas says of the OW01. "When you see a stan - dard OW01, you can see what you paid for. Parts of it were designed to be a racing bike. Simple things that we all take for granted like the first-ever detachable subframes—you could throw it down the road, put a new subframe on and away you went. That way you rarely damaged the frame, you just damaged the auxiliary bits. It had nice axle adjusters, and it was the first bike I ever saw with fully adjustable forks. "All the levers were light - weight aluminum; it had an alloy top triple-clamp nut; plus, it had dropped offset top triple-clamps so you had a lot more adjust- ment in front ride height. They had a lot of things on them that you just didn't get on a produc- tion bike that commanded such a massive price tag for the time." The engine was Yamaha's first real go at a proper short stroke engine. The FZ750's dimensions were 68 x 51.5mm. The new OW01 came in at a dis - tinctively oversquare 72 x 46mm with an 11.2:1 compression ratio (this was increased to up- wards of 12.5:1 via race kit head gaskets). Those dimensions allowed the revs to rocket up the scale, with peak claimed power of 121 hp coming in at 12,000 rpm; torque was measured at a claimed 51 lb-ft at 9000 rpm. Those were blazing numbers for a standard production bike back in 1989. Indeed, 1989 really signaled the start of the power race, as figures climbed expo - nentially over the next 10 years to near Grand Prix levels by the end of the 20th century. The OW01 followed the RC30's lead in using ultra- special titanium conrods. These were bolted to a plain bearing crank down the bottom and pumped two-ring forged alumi - num pistons up top—and went a way to explaining why this thing cost as much as it did! Thanks to the use of only two piston rings (one oil and one com - pression), the OW01 has been known to like a drink of oil. As was Yamaha's signature of the time (and for a long time after), they fitted their five-valve (two 23mm inlet and three 24.5mm exhaust) cylinder head. Feeding the beast was a quartet of downdraft Mikuni BDST 38mm carburetors with removable tops for quick needle changes in the pits, mixing with the fresh air routed from the front of the fairing to the airbox in front of the fuel tank. Cooling came via a single piece radiator, rather than the twin unit on the RC30 (which was replaced for racing anyway). On the exhaust side, the OW01 had Yamaha's EXUP valve to optimize backpressure and overall horsepower. It worked by what is now a primitive micro - computer driving a servomotor CNII ARCHIVES P122