<P> September 8 , 2009 , Yamaha introduced its all - new YZ450F with fuel injection . The engine cylinder is rearward slanted , the crank rod angle has been changed to provide a more complete combustion , the 5 - valve head is now a 4 - valve head , the gas tank is located under the seat , the exhaust pipe exits the rear of the cylinder , and the air intake is now in the front of the bike . They have a new bi-lateral frame which allows for new improved steering and the new engine components . The entire package comes together to create a bike that is mass - centralized . The bike was introduced by Yamaha Factory Motocross rider James Stewart. The top speed has been recorded at 80 mph stock . </P>
<P> September 8 , 2009 , Yamaha introduced its all - new YZ450F with fuel injection . The engine cylinder is rearward slanted , the crank rod angle has been changed to provide a more complete combustion , the 5 - valve head is now a 4 - valve head , the gas tank is located under the seat , the exhaust pipe exits the rear of the cylinder , and the air intake is now in the front of the bike . They have a new bi-lateral frame which allows for new improved steering and the new engine components . The entire package comes together to create a bike that is mass - centralized . The bike was introduced by Yamaha Factory Motocross rider James Stewart. The top speed has been recorded at 80 mph stock . </P>
when did yamaha start fuel injection on dirt bikes
when did yamaha start fuel injection on dirt bikes
September 8 , 2009
September 8 , 2009