2018 Yamaha YZ250F

2018 Yamaha YZ250F

The fuel injected YZ250F offers excellent power and amazing cornering performance thanks to exhaustive mass centralization efforts and a compact, super responsive chassis design. When this latest YZ450F was introduced in 2017, journalists were shocked by the wide spread of power the YZ250F produces, even from low rpms. The YZ250F has the response and depth of power that the competition can't match.

Yamaha's innovative engine design with forward mounted fuel injection delivers class leading power & handling. The "reversed" engine design concentrates many of the motorcycle's heaviest components; engine, fuel tank & exhaust system, towards the center of the motorcycle achieving excellent mass centralization and reduced gyroscopic effects for light , nimble, championship winning performance.

Features may include:

• Design goals for the fuel injected YZ250F are a balance of easy cornering & a lightweight feeling. thanks to excellent mass centralization. The fuel injected engine features a wide, controllable power band that sets the standard in the 250 class.

• "Reversed" liquid-cooled, 250cc, DOHC, 4-valve (titanium), single with fuel injection.

• Rearward slanted, reversed cylinder design.

• "Reversed" engine design (FI system is front mounted, exhaust exits from rear of cylinder).

• 4-valve cylinder head features a 13.5:1 compression ratio.

• Lightweight titanium valves.

• Automatic cam chain tensioner.

• High lift intake & exhaust camshafts.

• "Liner-less" lightweight aluminum cylinder features a ceramic composite coating applied directly to the aluminum block.

• Cylinder "cutaways" allow air "trapped" under the piston to enter a special side chamber (cutaway).

• Crankcase also utilizes special "cutaways."

• Lightweight, short-skirt, forged aluminum piston.

• Lightweight piston pin with diamond like coating (DLC).

• Piston oil cooler jet nozzle directs oil to the desired portion of the cylinder & underside of piston.

• Ball bearing style crankshaft.

• Nickel-chromium-molybdenum connecting rod.

• Lightweight gear driven counter balancer shaft.

• 5-speed transmission utilizes a 2-bar, floating shift guide system & a 14 mm shift shaft.

• Heavy duty, clutch with quick access magnesium outer cover & on the fly "barrel" adjuster.

• 44mm Keihin throttle body fuel injection system.

• Injector spray pattern, spray direction & distance to the intake valves have been optimized.

• Compact "Bilateral Beam" aluminum frame.

• Lightweight, tapered aluminum swingarm.

• Lightweight detachable rear sub frame.

• 48mm, adjustable, inverted, Kayaba "SSS" cartridge fork offers 310mm (12.2") of wheel travel.

• Fork features a twin-chamber, "Speed Sensitive System" (SSS) design

• Fork features a Transfer Control Valve (TCV).

• Large "wrap-around" plastic fork protectors.

• Adjustable handle bar holders offer a total of 4 different handlebar positions with an adjustment range of 30mm.

• Monocross link rear suspension with 315 mm (12.4") of wheel travel.

• 270 mm floating front "wave-style" disc & compact Nissin twin piston caliper.

• 245 mm rear disc brake uses a "wave-style" disc & single piston Nissin caliper & master cylinder.