2017 Yamaha YZ250F - Demo Bike
Featuring a "reversed" rear slanted engine design for mass centralization, minimal bodywork and a proven KYB "SSS" suspension system, the YZ450F offers class leading power in a 250 sized chassis. The YZ450F balances the 3 essential elements of an ultimate motocrosser: easy cornering, lightweight & compactness and a deep, useable power band.
- Revised air filter cover & fasteners
- Revised rear wave-style brake rotor
- New tire tread pattern front & rear
- Revolutionary reversed engine design with front mounted FI system & rear exiting exhaust
- Mass centralizing rearward-slanted-cylinder helps keeps weight centred in the chassis
- "Battery-less" 44mm throttle body FI & easy access airbox
- Compact aluminum Bilateral Beam frame & aluminum swingarm
- Industry-leading, fully adjustable KYB® "SSS" fork & Monocross rear suspension
- Large 270 mm front disc brake & twin piston caliper
- Design goals for the YZ450F are a balance of easy cornering, a lightweight & compact feeling due to excellent mass centralization and a deep power band tuned for excellent "ride-ability & controllability".
- "Reversed" liquid-cooled, 450cc, DOHC, 4-valve (titanium), 4-stroke, single with fuel injection.
- Rearward slanted, reversed cylinder design.
- "Reversed" engine design (FI system is front mounted, exhaust exits from rear of cylinder).
- Compact 4-valve cylinder head features a 12.5:1 compression ratio.
- Lightweight, hollow intake & exhaust cams
- Lightweight titanium valves use load-reduced oval valve springs.
- Automatic cam chain tensioner.
- Lightweight, ceramic composite plated aluminum cylinder.
- Cylinder is "offset" relative to the crankshaft (to exhaust side)
- Cylinder "cutaways" allow air "trapped" under the piston to enter a side chamber (or cutaway).
- Crankcase also utilizes special "cutaways"
- Lightweight, short-skirt, forged aluminum piston.
- Piston oil cooler jet nozzle directs oil to the cylinder, rod & underside of piston.
- Carburized (type of heat treatment) connecting rod for excellent durability.
- Compact, lightweight "Bilateral Beam" aluminum frame.
- Lightweight, tapered aluminum swingarm.
- Lightweight detachable rear sub frame.
- Adjustable handlebar holders offer a total of 4 different handlebar positions with an adjustment range of 30mm.
- 48mm, adjustable, inverted, Kayaba "SSS" cartridge fork with 310mm (12.2") of wheel travel.
- Fork features a twin-chamber, "Speed Sensitive System" design
- Fork also features a Transfer Control Valve (TCV).
- Large "wrap-around" plastic fork protectors provide excellent lower fork tube protection.
- Monocross link rear suspension with 315 mm (12.4") of wheel travel.
- 270mm floating front "wave-style" disc & compact Nissin twin piston caliper.