The YZ250F is aimed at taking the quarter litre motocross class to the next level. Design goals of the new machine are increased power and optimal handling. The reverse-engine layout that has proved so successful on the 450 was selected to achieve these goals.
The engine features a fuel injection system, with revised fuel and ignition timing, that gives a great throttle response and doesn’t need to be set to temperature or altitude like a carb does.
The development team has made the new 250F smaller, lighter and easier to use. The reversed engine layout also helps with concentrating the heavy masses around the centre of gravity.
- Reverse fed fuel injected DOHC, 4-valve engine with offset cylinder. By offsetting the cylinder from the centre of the crankshaft, friction losses are further reduced.
- Though it may look similar, the main frame is an all new construction.It is created using 10 different types of forged, cast and extruded aluminium parts that are welded together into one unit with outstanding strength, rigidity balance and shock absorbing capacity that contribute to superior cornering performance.
- Quick release fastners on the airbox allows for easy access, to the large capacity air filter.
- The muffler is moved forward. The exhaust pipe, which needs a certain length for good low and mid range torque, winds around the cylinder head like a snake, centralising weight.
- Handlebars are rubber mounted for less fatigue when riding and, with less vibrations coming through, a better ‘feel’ of the front wheel.
- Graphics on the bike are not stickers but a new ‘in-mould’ design for greater durability.
|Engine Type||Liquid-cooled, 4-stroke, DOHC, 4-valves|
|Bore x Stroke||77 x 53.6 mm|
|Lubrication System||Dry sump|
|Fuel Management||Fuel Injection|
|Fuel Tank Capacity||7.5 L|
|Oil Capacity||0.9 L|
|Final Transmission||Constant mesh 5-speed|
|Seat Height||965 mm|
|Ground Clearance||330 mm|
|Dry Weight||99 kg|
|Wet Weight||105 kg with 7.5 litres of fuel|
|Frame Type||Bilateral Beam|
|Suspension Front||Telescopic fork, 330mm travel|
|Suspension Rear||Swingarm (link suspension), 315mm travel|
|Brakes Front||Hydraulic single disc|
|Brakes Rear||Hydraulic single disc|
|Tyres Front||80/100-21 MS32|
|Tyres Rear||100/90-19 MS32|