<P> The Yamaha YZ250F is a motocross motorcycle first released in 2001 by Yamaha . It has a five - valve, DOHC, four - stroke engine and initially had a steel frame and an aluminum subframe, which was replaced in the 2005 model with an all - aluminum frame . </P> <P> This combination leads to the YZ250F being praised for combining the broad - power characteristics of a four - stroke engine with the light handling more common in smaller, 125 cc two - stroke motorcycles . </P> <Table> <Tr> <Td> 2003 </Td> <Td> Automatic decompression exhaust cam </Td> </Tr> <Tr> <Td> 2006 </Td> <Td> Aluminium frame </Td> </Tr> <Tr> <Td> 2008 </Td> <Td> New engine </Td> </Tr> <Tr> <Td> </Td> <Td> New engine layout, with lower center of gravity </Td> </Tr> <Tr> <Td> 2014 </Td> <Td> Rear slant cylinder, Fuel Injection </Td> </Tr> </Table> <Tr> <Td> 2003 </Td> <Td> Automatic decompression exhaust cam </Td> </Tr>

When did yamaha start fuel injection on yz250f