The fuel-injected YZ450F will enters its third season in the FIM MX1 Motocross World Championship in 2012 for what will be the ninth campaign since the series reverted to MX1 and MX2 class regulations in 2004.

With the introduction of the four-stroke YZM400F factory prototype in 1997 Yamaha changed off-road motorcycle sport as few other manufacturers have ever achieved before. The YZM400F brought four-stroke power and traction with an agile two-stroke type of chassis to the race track, a concept that in the end proved to be more competitive than the commonly used two-stroke machines of that era. The initial stones in the YZ ‘wall’ of supremacy were laid in 1998 when Doug Henry took the YZ400F to a thrilling debut in the AMA-MX championship, winning five nationals on the way to the crown. He also gained four podiums within the Supercross campaign of that year.

In 1999, Andrea Bartolini won the machine's first Rider’s World Championship in the 500cc class with the production based YZ400FM and ever since that time Yamaha have led the four-stroke revolution. The bike has formed the basis of winning technology in MXGP, MX1, MX3 and AMA Supercross and AMA Nationals since the turn of the century; most notably through 426cc and onto 450cc for the MX1 class from the beginning of 2004. Stefan Everts won the 500cc world title in 2001, 2002 and MXGP crown with the 450cc model in 2003. He then added crowns in 2004, 2005 and 2006 before retiring triumphant.

In 2008 innovations of the production YZ450F involved a new aluminium frame with altered geometry, making the base for racing machinery extremely competitive straight from the crate.
For 2009, on the race-bike, an altered swing-arm and linkage system helped lighten and add precision to the handling while the rear hub also carried less weight. The 2009 YZ450FM as used in MX-GP was a further, refined development of the motorcycle that propelled the legendary Everts to his 2006 world title, winning fourteen from fifteen Grand Prix. Josh Coppins’ took the machine to within one race of the 2007 MX1 championship (taking five wins on the way) while Philippaerts claimed the title in only his second season in the premier category during 2008, continuing a fantastic run of results for Yamaha's strong four-stroke technology. In 2009 Antonio Cairoli used a De Carli-tuned version of the YZ450F to win the title at his first attempt.

World Champions
1999 - Andrea Bartolini - YZ400FM (MX500)
2001 - Stefan Everts - YZ500FM (MX500)
2002 - Stefan Everts - YZ500FM (MX500)
2003 - Stefan Everts - YZ450FM (MXGP)
2004 - Stefan Everts - YZ450FM (MX1)
2005 - Stefan Everts - YZ450FM (MX1)
2006 - Stefan Everts - YZ450FM (MX1)
2008 - David Philippaerts - YZ450FM (MX1)
2009 - Antonio Cairoli - YZ450F (MX1)

2010 saw Yamaha dazzle the market and race paddocks again with a brand new YZ450F. The rear slanting and re-positioned fuel-injected engine unit benefitted from a new configuration with innovative displacements of the airbox and exhausts. Housed within a chassis that helped lower and further centralise the riding sensation the motorcycle was feted by the world’s press. YRRD (Yamaha Rinaldi R&D) sharpened this formidable piece of equipment and two Grand Prix wins were taken in 2010. A refined version of the motorcycle in the hands of Philippaerts and Steven Frossard for 2011 permitted a total of four Grand Prix victories from fifteen rounds. The Rinaldi-entered YZ450FM was the only bike in the class to carry all team members to the top step as Gautier Paulin claimed the final GP of the season in Italy. This was a unique achievement in 2011. Frossard was runner-up in his first season in the premier class meaning that Yamaha’s last two riders in the works team have been able to classify 1st and 2nd in their first terms on the YZ450F.

For 2012 the evolution process continues with YRRD again making further steps with controllable performance delivery of the YZ450F while also adhering to the strict regulations to reduce noise levels. Working in-house on their production-based suspension system for the second year in a row and also keeping a consistent riding staff with Philippaerts and Frossard again contracted for the sixteen round ’12 championship the Rinaldi Monster Energy Yamaha team are well-placed for yet more gains. Former British Champion Shaun Simpson will be the third rider on YZ450F machinery, using a YRRD engine in a chassis prepared by the Dixon splinter of Monster Energy Yamaha and using Ohlins suspension.

Engine:
YRRD tuned head
YRRD Camshaft
YRRD new Crankshaft
Akrapovic exhaust pipe
GET programmable ECU

Chassis and others:
Production-based suspension front and rear (Ohlins for Simpson)
Special triple clamp with different off-set compared to 2010
Front disc brake – 280mm for Frossard, 270mm for Philippaerts