FUEL INJECTION FOR THE 250
A main feature of the 2014 Yamaha YZ250F is its new liquid-cooled, DOHC 4-valve, fuel-injected engine. Drawing from its big brother, the YZ450F, the new engine adopts fuel-injection and Yamaha's rear-inclined cylinder position to deliver more power than the 2013 250cc model. A new 44mm throttle body comes with 3-dimensionally mapped control of the volume of fuel injected, ignition timing based on engine rpm and throttle opening. The MX bike also sports Yamaha’s newly designed aluminum bilateral beam frame.