Yamaha YZR500

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Yamaha YZR500
Yamaha YZR500 (OW20)
Manufacturer Yamaha Motor Company
Production 1973 - 2002
Predecessor Yamaha YZ634A
Successor Yamaha YZR-M1
Engine 500 cc two-stroke

The YZR500 was the Yamaha Motor Corporation’s entry for 500cc Grand Prix motorcycle racing between the years of 1973 and 2002.

the 1989 version of bike ridden by American Wayne Rainey

Successes[edit]

Riders who rode it to world championships are Giacomo Agostini (1975), Kenny Roberts (1978, 1979, 1980), Eddie Lawson (1984, 1986, 1988) and Wayne Rainey (1990, 1991, 1992).

Chronology[edit]

Year Model Constructor's
championship
1973 OW20: Liquid-cooled, inline-4, 2-stroke engine, chromoly frame. Yamaha’s first 500cc factory bike won from the outset at the first round of the 1973 season, ridden by Jarno Saarinen. 2nd
1974 OW23: Yamaha’s first machine created specifically for 500cc racing. Yamaha won their first 500cc constructor’s championship with it and in 1975 Giacomo Agostini rode the revised OW26 to a world championship as well as giving Yamaha their second 500cc constructor’s championship. 1st
1975 1st
1976 2nd
1977 OW35: Changes were made to the valve intake system, stroke ratio and carburator. 2nd
OW35K: Introduction of Yamaha’s Power Valve System (YPVS). Kenny Roberts won his first of three championships with it.
1978 2nd
1979 OW45 2nd
1980 OW48: Introduction of an aluminum frame to the YZR500. 2nd
OW48R: At round 4 of the season, the YZR500 returned to a steel frame, and the engine had the outer cylinders reversed and thus rear-directional exhaust.
1981 OW53: Same rear-directional exhaust as the OW48R, and the aluminum frame used a squared cross-section. Last inline-4 YZR500. 2nd
OW54: Square-4 engine, rotary disc valve.
1982 OW60 2nd
OW61: The first V4 engine in a 500cc Grand Prix motorcycle. Also had a new frame structure that was the basis for the Deltabox frame, which was developed by Spanish engineer Antonio Cobas.[1]
1983 OW70: Introduction of the aluminum Deltabox frame and designed specifically for a 17-inch front wheel (from 18 inches). 2nd
1984 OW76: Crankcase reed valve system. Eddie Lawson wins the rider championship with it. 2nd
1985 OW81: Re-designed V-4 engine. Eddie Lawson won the rider's championship with it. 2nd
1986 1st
1987 OW86: Improvements to the exhaust and cooling systems. 1st
1988 OW98: A new exhaust layout of both pipes going under the engine and out the right side required an asymmetrical swingarm. Eddie Lawson won the rider's championship on it. 1st
1989 OWA8: Introduction of a data-recording device. 2nd
1990 OWC1: Wayne Rainey won his first rider's championship on it. 1st
1991 OWD3: New regulation came into effect: the minimum weight would be 131 kg (for the 4 cylinders bikes). Yamaha used in this year first (and last) chip controlled suspension (CES). 1st
1992 OWE0: In the latter-half of the season, Yamaha introduced their own "big-bang" firing order to the YZR500. Third championship for Wayne Rainey. 2nd
1993 OWF2: An extruded aluminum frame was designed to resist flex from increased power output, though Wayne Rainey complains that it is too stiff, and in round 8 Rainey switches to a chassis used by Team ROC. 1st
1994 OWF9: Re-design of the fairing and introduction of ram-air intake. 3rd
1995 3rd
1996 OWJ1: New alloy for the engine and new design for the frame. 2nd
1997 OWH0: The "V" was widened to allow a larger air box. The OWJ1 and OWH0 were developed simultaneously and used in reverse order during the season. 2nd
1998 OWK1: Move to unleaded fuel. 2nd
1999 2nd
2000 OWK6: General improvements to the engine, frame and cowl. 1st
2001 OWL6 2nd
2002 OWL9: The 28th and last generation of the YZR500 had to compete against the newly allowed 4-stroke machines. 2nd[2]

Notes[edit]

  1. ^ Adams, Dean. Antonio Cobas Dead at 52 Superbikeplanet.com 2004.
  2. ^ All but 10 points that counted towards the Constructor's championship were scored by Yamaha's YZR-M1 4-stroke machine

External links[edit]