New Yamaha WR250R2009 : Photo and Reviews

 New Yamaha WR250R2009 : Photo and Reviews






The WR250R draws upon over 50 years of Yamaha experienc, on pavement and off, to bring you a bike that'll take you practically anywhere - one hundred percent legally. More power than you might expect flows from its high-tech fuel-injected DOHC engine while a hybrid aluminum frame keeps you in complete command. Pavement optional.
super light titanium intake valves and electronic fuel injection.
Super convenient electric starting means fast, sure starts.
Hassle free automatic decompression system ensures fast restarts in any gear.
Lightweight magnesium cylinder head cover helps reduce weight.
Double overhead cam, 4-valve combustion chamber features a compact "pent-roof" design for maximum breathing efficiency. Shim under bucket type valve adjustment is used.
Downdraft -type straight design intake port provides the most efficient intake flow for maximum engine performance.
Intake side, lightweight titanium valves and load-reduced springs decrease weight by more than 40% (Vs steel valves). Titanium valves reduce reciprocating mass for faster-revving, plus reduced frictional losses for smoother-hitting power delivery across the rev range. Intake valves are 30mm in diameter, while the steel exhaust valves are 24.5mm in diameter.
Steep valve angles, 11.5 degrees on the intake side and 12.5 degrees on the exhaust produce a more compact combustion chamber.
Dual electrode NGK CR9EK spark plug is located in the centre of the combustion chamber for fast, controlled combustion and great throttle response.
Ceramic composite cylinder provides excellent heat dissipation for consistent power delivery, reduced oil consumption, reduced friction for increased power and reduced weight.
Special cylinder design features cutaways that allow the air "trapped" under the piston to enter a side chamber (or cutaway) to reduce horsepower-robbing "pumping losses."
Special design Crankcases also utilize cutaways to reduce "pumping losses." The crankcase cutaways match the cutaways in the cylinder to reduce 'pumping losses.
The crankcases feature a "tri-axis" design for the crankshaft, main and drive axles. This tri-axis design keeps the crankcases more compact while also centralizing mass for better handling. All of the shafts are positioned low in the cases to maintain a low centre of gravity for great handling and maneuverability.
Lightweight, high strength, short-skirt, forged aluminum piston provides great durability and its lightweight design means fast engine response.
Lightweight roller bearing style crankshaft with optimized mass delivers excellent response and strong acceleration.
Single balancer shaft reduces vibration for improved rider comfort and reduced rider fatigue. This bike can cruise at highway speeds comfortably.
Special design high performance camshafts (intake & exhaust) provide outstanding class leading power. The cams feature a WPC (Wonder Process Craft) treatment that increases surface hardness for great durability and reduced sliding resistance.
Wet sump lubrication system is used. This system reduces weight and the number of moving parts versus a dry sump system. Piston oil cooler nozzle is used to maintain consistent piston temperatures for durability.
Oil volume in engine has been optimized to reduce weight and oil "drag" related power losses.
Easy access paper-type oil filter is used.
Compact design "clip stopper"- type hydraulic automatic cam chain tensioner reduces maintenance and mechanical engine noise.
38mm, Mikuni electronic throttle body type fuel injection system is used (38EIS). This system is a return-less FI system with TPS (throttle position sensor). This system provides excellent throttle response, great fuel economy, reduced emissions and a choke-free design. Throttle response and acceleration are excellent.
Long nozzle type 12 hole injector is used and provides a dual spray pattern for best in class performance.
Easy to service 4.1 liter airbox with a new intake control valve provides state of the art intake and emission control. The foam air filter is a washable design
Compact 16 bit ECU features 3D ignition mapping to accommodate the engine power characteristics. The ECU provides optimal timing at all rpms for fast engine response.
Lightweight direct ignition coil is integrated into the plug cap to reduce weight and complexity
Wide ratio 6-speed transmission features gear ratios designed for both on and off road riding. This transmission adopts a "shower type" lubrication system for great reliability.
Heavy-duty clutch matches engine output and offers a light, progressive clutch feel with less lever effort for smoother shifting.
Quick-access, lightweight aluminum outer clutch cover allows fast, easy access to the clutch.
Single, 9.5KW rad is used. The "exhaust air" (after it has passed through the rad) is directed away from the rider for excellent rider comfort. An electric cooling fan maintains consistent engine temperatures even in stop and go traffic. The single rad is located on the left side of the fuel tank.
Lightweight, compact "rare-earth-type" ACM (Alternative Current Magnet … 14V & 350W output ) is used.
Lightweight exhaust system features a stainless steel header pipe and a compact 3-stage expansion type upswept muffler with a honeycomb catalytic converter to reduce exhaust emissions. This system maximizes engine power and allows hassle-free replacement of the oil filter. It features a cleanable screen-type spark arrestor. Heat shields protect rider and passenger.
The exhaust system also features Yamaha's EXUP System (Exhaust Ultimate Power Valve). The single butterfly valve prevents the "blow back" phenomenon caused by "valve overlap". The EXUP system eliminates "flat spots" in the power band and reduces emissions too.
Solenoid activated AIS (Air Induction System) reduces harmful exhaust emissions like carbon dioxide and hydro carbons.

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