Yamaha WR450F

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Yamaha WR450F
2010 Yamaha WR450F at 2009 Seattle International Motorcycle Show 1.jpg
2010 Yamaha WR450F
Manufacturer Yamaha Motor Company
Parent company Yamaha Corporation
Class Enduro
Engine Single-cylinder, DOHC, Multivalve, water-cooled, four-stroke
Transmission 5-speed, wet clutch, chain drive
Suspension

Front: Kayaba inverted fork; fully adjustable

Rear: single shock; fully adjustable
Brakes Hydraulic single disc brakes

The Yamaha WR450F is an off-road motorcycle made by Yamaha Motor Company. It currently has a 450 cc (27 cu in) liquid-cooled single-cylinder engine. First offered in 1998 at 400cc, it shared many components and design concepts with the YZ400F motocross model. It is basically the racing YZ450F detuned slightly for more controllable power, with a headlight and lighting coil, softer suspension, a kickstand, lower noise specifications, larger radiators and lower emissions. The WR in the name indicates a wide-ratio gear box common to most enduro or trail bikes and stands in contrast to the close-ratio gearbox essential to a motocross racer. Over the years the WR has benefited from the advances made in the YZ motocross version gaining displacement and advancements such as an aluminum frame and improved suspension. Over much of its life the weight of the WR450F has remained fairly constant ranging from 244 to 249 pounds dry weight.[1]

2003 450cc displacement, Automatic decompression exhaust cam and electric starting, side access airbox
2006 Digital display, revised CDI map
2007 Aluminium frame, new headlight, LED taillight, revised dry-sump engine & camshafts (less lift and duration)
2012 Fuel injection, YZ250F-based chassis, KYB SSS-type forks
2016 Reverse slant, 4-valve engine
First Generation WR400F
Yamaha WR 400F 2000.jpg
Production 1998-1999
Successor WR426F
Engine Five-valve, 400 cc
Fuel capacity 3.2 US gal (12 l; 2.7 imp gal)

First generation: WR400F - 1998-2000[edit]

Yamaha introduced the WR 400F in 1998. The 400F is a four-stroke off-road motorcycle produced for three years, beginning in 1998 and ending in 2000 (only the YZ was upgraded to 426 cc in 2000). The WR400F is related to the YZ400F, a motocross model. Like the YZ400, it was considered to be a groundbreaking model in motorcycle history, ushering in the four-stroke era which ended the dominance of two-stroke engines in motocross and offroad racing. While many modern performance four-stroke dirt bikes have been criticized for excessive rebuild costs and short motor lifespans, the Yamaha WR400F has an impressive record of reliability, often attributed to its steel valves and generous oil capacity.[citation needed]

Second Generation WR426F [2][3]
Production 2001-2003
Predecessor WR400F
Successor WR450F
Engine Titanium five-valve, 426 cc, 95mm x 60.1mm stroke, compression ratio 12.5:1
Brakes 250mm front, 245mm rear
Wheelbase 58.7 in (1,490 mm)
Fuel capacity 3.2 US gal (12 l; 2.7 imp gal)

Second generation: WR426F - 2001-2002[edit]

In 2001 the WR400F's engine was uprated and it became the WR426F increasing the displacement to 426 cc (26.0 cu in) for greater power and throttle response.[citation needed] A beefier YZ style clutch basket and plates than those on the WR400 improved clutch performance. Frame geometry was identical to the 2002 YZ250 and YZ426F with a 58.7 inch wheelbase and 14.7 inches of ground clearance. This was the last WR to make use of a manual compression release for starting.

Third generation: Yamaha WR450F - 2003-2006[edit]

Third Generation WR450F
Production 2003 through 2006
Predecessor WR426F
Engine Titanium five-valve, 449 cc, 95mm x 63.4mm stroke, compression ratio 12.3:1
Frame type Steel
Suspension Front: 11.8 in (300 mm) travel
Rear: 11.6-in travel
Brakes Front: 250 mm disc
Rear: 245 mm disc
Tires Front: 80/100-21 51M
Rear: 110/100-18 64M
Wheelbase 58.5 in (1,486 mm)
Dimensions L: 85.6 in (2,174 mm)
W: 32.5 in (826 mm)
H: 51 in (1,295 mm)
Seat height 38.6 in (980 mm)
Weight 244 lb (111 kg) (dry)
273 lb (124 kg) (wet)
Fuel capacity 2.6 US gal (9.8 l; 2.2 imp gal) 2003-2005, 2.1 US gal (7.9 L) 2006
Related YZ450F, WR250F

For 2003, the engine displacement was increased to 449 cc, the fuel tank was reduced to 2.6 gallons [1] and the bike came with an electric starter as standard equipment. The 2005 WR weighed in at 244 pounds dry, the seat height was reduced to 38 inches and the fuel tank was decreased to 2.1 gallons.[1][4] The 2006 WR weighed in at 249 pounds dry[1] and produced 42 horsepower.[5]

A limited production version of the WR450F was the WR450F 2-Trac, which featured 2-wheel drive. The gearbox output sprocket drove a short, fully enclosed chain to a pump, which in turn pushed the oil to the front hub via the pipe and back via the parallel pipe.[6] A maximum of 15% of the power was transmitted to the front wheel at any time.[6] Yamaha planned on building 250 2-Tracs in 2004, but only a few were built, which were used for enduro racing.[6] 2006 was the last year of the steel frames.

Fourth generation: Yamaha WR450F - 2007-2015[edit]

Fourth Generation WR450F
2010 Yamaha WR450F at 2009 Seattle International Motorcycle Show 1.jpg
2010 Yamaha WR450F
Manufacturer Yamaha Motor Corporation
Production 2007 through 2015
Predecessor WR450F
Engine Titanium five-valve, 449 cc, 95mm x 63.4mm stroke, compression ratio 12.3:1
Transmission 5-speed, constant mesh[7]
Frame type Aluminum, semi-double cradle[7]
Suspension Front: KYB cartridge forks with 11.8 in (300 mm) travel
Rear: KYB shock with 12 in (305 mm) travel[7]
Brakes Front: 250 mm disc
Rear: 245 mm disc
Tires Front: 80/100-21 51M
Rear: 110/100-18 64M
Rake, trail 27.3°, 117 mm (4.6 in) [7]
Wheelbase 1,485 mm (58 in)[7]
Dimensions L: 2,175 mm (86 in)[7]
W: 825 mm (32 in)[7]
H: 1,295 mm (51 in)[7]
Seat height 980 mm (39 in)[7]
Weight 248 lb (112 kg)[7] (dry)
273 lb (124 kg) (wet)
Fuel capacity 2.11 US gal (8.0 L)[7]
Related YZ450F, WR250F

For 2007, the WR gained an aluminum frame dropping the weight from 249 to 246 pounds.[8] In addition to the aluminum frame, the 2007 WR450F saw a revised dry-sump engine, with a new balancer, cylinder head, and camshafts with less lift & duration than previous generations and restyled plastics. 2009 saw new graphics, and 2010 was not sold in the USA.[clarification needed]

For 2012, the WR450F added fuel-injection and a compact YZ250F-based chassis to provide a lighter feel and more manueverablity.

Fifth generation: Yamaha WR450F - since 2016[edit]

Fifth Generation WR450F [9]
Production Since 2016
Predecessor WR450F
Engine Fuel-injected, Titanium four-valve, 97.0 mm x 60.8 mm stroke, compression ratio 12.5:1
Suspension Front: 12.2 in (310 mm) travel
Rear: 12.5 in (318 mm) travel
Brakes Front: 270 mm disc
Rear: 245 mm disc
Tires Front: 80/100-21 51M
Rear: 120/90-18 64M
Wheelbase 57.7 in (1,466 mm)
Dimensions L: 85.2 in (2,164 mm)
W: 32.5 in (826 mm)
H: 50.4 in (1,280 mm)
Seat height 38.0 in (965 mm)
Weight 249 lb (113 kg) (dry)
271 lb (123 kg) (wet)
Fuel capacity 2.0 US gal (7.6 l; 1.7 imp gal)
Related Yamaha YZ250FX

For 2016, the WR was given the reverse slant, 4-valve, fuel injected motor previously available in the YZ450F since 2010. Yamaha also introduced a new model, the YZ450FX, a more Enduro competition oriented version of the off-road 450 utilizing more design elements of the motocross model such as stiffer suspension and a close ratio gear box while maintaining electric start and the 18" rear wheel.

For 2017, the WR450F largely remained the same, except for modifications to the air box cover as well as a change from silver to black rims.

For 2018, the WR450F remained similar to the 2016-2017 models, with a large distinction being that the bike was no longer available to register as green sticker in the state of California.

https://www.yamahamotorsports.com/off-road/models/2016/wr450f

See also[edit]

References[edit]

  1. ^ a b c d http://www.yamaha-motor.com/sport/products/modelspeccompare/210/1132/0/compare.aspx
  2. ^ 2001 Yamaha WR426F, Motorcycles.com, 2001 
  3. ^ 2002 Yamaha WR426F, MotorcycleUSA.com, 2002 
  4. ^ "2005 WR450F vs CRF450X Comparo Conclusion". Motorcycle USA. 2005-05-23. Retrieved 2011-12-27. 
  5. ^ "2006 Yamaha WR450 Comparison". Motorcycle USA. 2006-05-22. Retrieved 2011-12-27. 
  6. ^ a b c Blezard, Paul. "Yamaha WR450F 2-Trac - Review". www.mcnews.com.au. Retrieved 14 March 2013. 
  7. ^ a b c d e f g h i j k Owner's Service Manual WR450FW. August 2006. 
  8. ^ "2007 Yamaha WR450F WR250F". Motorcycle USA. Retrieved 2011-12-27. 
  9. ^ 2016 Yamaha WR450F Off-Road Motorcycle - Specifications, Yamaha Motor Corporation USA, 2016