Editing Yamaha YZR500

{{Infobox Motorcycle
| name = Yamaha YZR500
| image = [[Image:YAMAHA YZR500 OW20.jpg|200px|Yamaha YZR500 (OW20)]]
| aka = 
| manufacturer = [[Yamaha Motor Company]]
| production = 1973 - 2002
| predecessor = [[Yamaha YZ634A]]
| successor = [[Yamaha YZR-M1]]
| parent_company = 
| class = 
| platform = 
| engine = 500&nbsp;[[cubic centimeter|cc]] [[Two-stroke cycle|two-stroke]]
| transmission =
| rake =
| trail =
| wheelbase =
| length = 
| width = 
| seat_height =
| dry_weight =
| wet_weight = 
| fuel_economy =
| fuel_capacity =
| related = 
| similar = [[Suzuki RGV500]]<br>[[Honda NSR500]]
}}
The '''YZR500''' was the [[Yamaha Motor Corporation]]’s entry for 500cc [[Grand Prix motorcycle racing]] between the years of 1973 and 2002. Riders who rode it to world championships are [[Giacomo Agostini]] ([[1975 Grand Prix motorcycle racing season|1975]]), [[Kenny Roberts]] ([[1978 Grand Prix motorcycle racing season|1978]], [[1979 Grand Prix motorcycle racing season|1979]], [[1980 Grand Prix motorcycle racing season|1980]]), [[Eddie Lawson]] ([[1984 Grand Prix motorcycle racing season|1984]], [[1986 Grand Prix motorcycle racing season|1986]], [[1988 Grand Prix motorcycle racing season|1988]]) and [[Wayne Rainey]] ([[1990 Grand Prix motorcycle racing season|1990]], [[1991 Grand Prix motorcycle racing season|1991]], [[1992 Grand Prix motorcycle racing season|1992]]). The Yamaha YZR500 has achieved more wins or [[podium]]s than any other bike.
==Chronology==
{| class="wikitable" style="font-size: 95%;"
|-
! Year
! Model
! [[List of Grand Prix motorcycle racing World Champions#By manufacturer|Constructor's<br>championship]]
|-
! [[1973 Grand Prix motorcycle racing season|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 Grand Prix motorcycle racing season|1973 season]], ridden by [[Jarno Saarinen]].
| 2nd
|-
! [[1974 Grand Prix motorcycle racing season|1974]]
| rowspan=2 | '''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 Grand Prix motorcycle racing season|1975]]
| 1st
|-
! [[1976 Grand Prix motorcycle racing season|1976]]
| 
| 2nd
|-
! rowspan=2 | [[1977 Grand Prix motorcycle racing season|1977]]
| '''OW35''': Changes were made to the valve intake system, [[stroke ratio]] and [[carburator]].
| rowspan=2 | 2nd
|-
| rowspan=2 | '''OW35K''': Introduction of Yamaha’s Power Valve System (YPVS). [[Kenny Roberts]] won his first of three championships with it.
|-
! [[1978 Grand Prix motorcycle racing season|1978]]
| 2nd
|-
! [[1979 Grand Prix motorcycle racing season|1979]]
| '''OW45'''
| 2nd
|-
! rowspan=2 | [[1980 Grand Prix motorcycle racing season|1980]]
| '''OW48''': Introduction of an aluminum frame to the YZR500.
| rowspan=2 | 2nd
|-
| '''OW48R''': At round 4 of the season, the YZR500 returned to a steel frame, and the engine had rear-directional exhaust.
|-
! rowspan=2 | [[1981 Grand Prix motorcycle racing season|1981]]
| '''OW53''': Same rear-directional exhaust as the '''OW48R''', and the aluminum frame used a squared cross-section. Last [[inline-4]] YZR500.
| rowspan=2 | 2nd
|-
| '''OW54''': Square-4 engine, rotary disc valve.
|-
! rowspan=2 | [[1982 Grand Prix motorcycle racing season|1982]]
| '''OW60'''
| rowspan=2 | 2nd
|-
| '''OW61''': The first [[V4 engine]] in a 500cc [[List of Grand Prix motorcycles|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.<ref>Adams, Dean. [http://www.superbikeplanet.com/2004/Apr/040414z.htm ''Antonio Cobas Dead at 52''] Superbikeplanet.com 2004.</ref>
|-
! [[1983 Grand Prix motorcycle racing season|1983]]
| '''OW70''': Introduction of the aluminum Deltabox frame and designed specifically for a 17-inch front wheel (from 18 inches).
| 2nd
|-
! [[1984 Grand Prix motorcycle racing season|1984]]
| '''OW76''': Crankcase reed valve system. [[Eddie Lawson]] wins the rider championship with it.
| 2nd
|-
! [[1985 Grand Prix motorcycle racing season|1985]]
| rowspan=2 | '''OW81''': Re-designed V-4 engine. [[Eddie Lawson]] won the rider's championship with it.
| 2nd
|-
! [[1986 Grand Prix motorcycle racing season|1986]]
| 1st
|-
! [[1987 Grand Prix motorcycle racing season|1987]]
| '''OW86''': Improvements to the exhaust and cooling systems.
| 1st
|-
! [[1988 Grand Prix motorcycle racing season|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 Grand Prix motorcycle racing season|1989]]
| '''OWA8''': Introduction of a data-recording device.
| 2nd
|-
! [[1990 Grand Prix motorcycle racing season|1990]]
| '''OWC1''': [[Wayne Rainey]] won his first rider's championship on it.
| 1st
|-
! [[1992 Grand Prix motorcycle racing season|1992]]
| '''OWE0''': In the latter-half of the season, Yamaha introduced their own [[NSR500#1990 - 1998|"big- bang" firing order]] to the YZR500. Second championship for [[Wayne Rainey]].
| 2nd
|-
! [[1993 Grand Prix motorcycle racing season|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 Grand Prix motorcycle racing season|1994]]
| rowspan=2 | '''OWF9''': Re-design of the fairing and introduction of [[ram-air intake]].
| 3rd
|-
! [[1995 Grand Prix motorcycle racing season|1995]]
| 3rd
|-
! [[1996 Grand Prix motorcycle racing season|1996]]
| '''OWJ1''': New alloy for the engine and new design for the frame.
| 2nd
|-
! [[1997 Grand Prix motorcycle racing season|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 Grand Prix motorcycle racing season|1998]]
| rowspan=2 | '''OWK1''': Move to unleaded fuel.
| 2nd
|-
! [[1999 Grand Prix motorcycle racing season|1999]]
| 2nd
|-
! [[2000 Grand Prix motorcycle racing season|2000]]
| '''OWK6''': General improvements to the engine, frame and cowl.
| 1st
|-
! [[2001 Grand Prix motorcycle racing season|2001]]
| '''OWL6'''
| 2nd
|-
! [[2002 Grand Prix motorcycle racing season|2002]]
| '''OWL9''': The 28th and last generation of the YZR500 had to compete against the newly allowed [[4-stroke]] machines.
| 2nd<ref>All but 10 points that counted towards the Constructor's championship were scored by Yamaha's [[YZR-M1]] [[4-stroke]] machine</ref>
|-
|}

==Notes==
{{reflist|1}}

==External links==
*[http://www.yamaha-motor.co.jp/profile/sports/race/history/machine/index.html Official Yamaha page for the history of the YZR500 (in Japanese)]

{{Grand Prix motorcycles}}
{{Yamaha motorcycles}}

[[Category:Yamaha motorcycles]]
[[Category:Grand Prix motorcycles]]