With the introduction of the revolutionary 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 in an agile two-stroke type of chassis to the race track, a concept that in the end proved to be more competitive then the commonly used two-stroke machines of that era.

Three seasons on, 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 2008 YZ450FM is a further, refined development of the motorcycle that propelled the legendary Stefan Everts to his 2006 world title, winning fourteen from fifteen Grand Prix. With Joshua Coppins and David Philippaerts as new riders, the Rinaldi team technicians have tuned the machine anew to accommodate the specific riding styles of their fresh personnel. It is what the team does best and the riders have felt ‘at home’ on the YZ from the outset.

Coppins’ praise for the machine that gave brought him to within one race of the 2007 MX1 championship (taking five wins on the way) is understandable looking at the fantastic results of Yamaha's strong four-stroke technology, with world championships won in:

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) 

The main innovations of the production YZ450F for 2008 involve a new aluminium frame with altered geometry, making the base for Coppins and Philippaerts’ factory bikes extremely competitive straight from the crate. In essence the team only needs to tailor the production bike to suit the riders' specific styles. 

The following major parts have been modified by Rinaldi's YRRD (Yamaha Rinaldi R&D) department

• Crankshaft   
• Piston   
• Cylinder head
• Camshaft   
• Ignition: programmable YRRD type   
• Exhaust pipe and silencer: GP FIM specification