2012 Yamaha YZ250F Review
An absolute pleasure to ride!
Totally updated and refined for 2012, the new YZ250F delivers unparalleled power and handling.
Supported by pro racers and weekend warriors, due to its seamless cornering ability, the new 2012 Yamaha YZ250F gets a boost of power from the mid to top power range and an updated chassis design.
New to the sport, or a seasoned pro, you\'ll appreciate the effortless handling and smooth, responsive power.
It\'s tricky building a bike that caters to the world\'s fastest racers, and those who just want to have some fun. The #1 demand from both sides is cornering performance; that\'s what our engineers and test riders focused on when developing the new YZ250F. For 2012, the 250F retains its superior cornering prowess but benefits from increased mid-to-top end power and a stronger, more rigid chassis surpasses current expectations. Take your competitiveness—or weekend fun—to an all-new level with Yamaha\'s potent YZ250F.
New for 2012 with more power and better handling.
The new 2012 YZ250F features a new Bilateral Beam frame, beefy new front suspension components, revised rear shock internals, and more rigidity in the swing arm axle block area. Engine refinements include a larger 39mm carburetor, optimized CDI, and lighter piston for more power as well as exceptional throttle response in the mid to high speed range.
2012 Yamaha YZ250F Highlights and Key Features:
Increased mid-to-top end power
Stronger, more rigid chassis
Revised suspension settings
•New optimized engine pumps out more power in the 8,000 to 12,000 rpm range with outstanding throttle response, thanks to new crankshaft webs, new vibration-reducing counterbalancer, new connecting rod, and low-friction piston rings, as well as a new piston, piston pin, and clip assembly that’s over 8% lighter overall than before. To take full advantage of these advancements, there’s also new CDI mapping and a bigger 39mm carb with freer breathing air cleaner cage. Added to the new frame and suspension refinements, this latest engine gives YZ250F amazing balance – a powerful, light-handling machine with performance that’s accessible to all levels of riders.
•The new-for-2012 Bilateral Beam frame has revised rigidity balance for superior cornering performance as well as great stability on rough, high-speed straights. Beefy new front suspension components plus revised rear shock internals and more rigidity in the swingarm axle block area give this new machine a serious handling advantage with light, quick steering.
•The styling emphasizes the bike’s lightweight and nimble handling character. The sharp, horizontal lines set the bike apart with a clean, aggressive look.
•New KYB® suspension is tuned to work with the also new Bilateral Beam frame for unmatched handling.
•There’s no disputing the YZ250F’s unmatched four-stroke prowess – it was the 1st four-stroke 250 motocross bike on the market, the 1st to win an international race, the 1st to win an AMA® Supercross,® and the 1st to take an AMA® U.S. Supercross Championship® title, as well as the ?rst to win an AMA® National race.
New for 2012:
•Engine refinements, including a larger 39mm carburetor, optimized CDI, and lighter piston with a lighter piston pin, mean YZ250F has more power as well as exceptional throttle response in the mid-to-high speed range.
•The crankshaft web design is revised to match the lighter piston and reduce high-rpm vibration.
•The air cleaner cage is a new design that provides increased airflow, contributing to the excellent throttle response in the mid-to-high speed range.
•The new muffler is designed to meet 94 dB standards.
•The new Bilateral Beam frame with a revised balance of longitudinal, lateral, and torsional rigidity is used for superior cornering performance, especially while exiting turns, as well as great stability on rough, high-speed straights.
•YZ250F has beefy new outer fork tubes and triple clamps. The result? An increase in the front fork assembly’s torsional rigidity for unmatched chassis stability.
•Fork offset has been changed from 25mm to 22mm to accommodate the new frame design. This shortened offset increases trail length which, in turn, contributes to excellent stability and reduces the inertial moment of the front fork assembly for quick, race-winning handling. The rider can take advantage of the higher level of performance throughout the turn.
•The redesigned axle block portions of the swingarm provide greater rigidity to further optimize the rigidity balance between the new frame and the revised front fork assembly.
•Front and rear suspension settings have been optimized for the new frame design, including a shock that uses a 16mm shaft for optimal hydraulic flow, resulting in exceptionally smooth suspension and great traction capability.
•New seat foam material has an excellent cushion feel.
•Both color options feature rich-looking black rims and a gold-color drive chain.
< strong>2012 Yamaha YZ250F Features and Benefits
Rev ised, liquid-cooled, 250cc, DOHC, 5-valve (titanium), 4-stroke engine features a 13,500-rpm redline. The modifications to the engine provide improved performance in the mid to high speed range.
The 13.5:1 compression ratio provides fast, controlled combustion and excellent engine performance.
Optimized 5-valve (3-intake & 2-exhaust) combustion chamber design provides the most efficient intake and exhaust flow for maximum power.
Titanium valves decrease weight by more than 40% over a conventional steel valve train and reduce reciprocating mass for faster-revving.
"Load reduced" valve springs reduce the amount of force required to open the valves and thereby minimizes power losses associated with friction and improves torque in the low and mid ranges.
Special chromium nitride coating on the tips of the intake valve stems reduces wear.
Ceramic composite cylinder bore is a "liner less" design with the ceramic coating sprayed directly on the aluminum block to create the "sleeve" the piston travels in. The benefits include reduced weight (no heavy iron liner), reduced friction, extended cylinder life and excellent heat dissipation for consistent power delivery.
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."
Lightweight engine crankcases also utilizes special cutaways to reduce "pumping losses." The crankcase cutaways match the cutaways in the cylinder for maximum efficiency.
Revised, short skirt forged piston with new rings and new piston pin reduce weight and mechanical vibration, while offering excellent durability. The weight reduction helps improves throttle response.
Revised balancer shaft ratio. The balancer shaft offsets the vibration produced by the crankshaft and influences the amount of engine vibration a rider feels, especially in the handlebar. For 2012 the balancer shaft ratio has been modified for reduced vibration, improved comfort and less rider fatigue.
Lightweight magnesium cylinder head cover.
Dry sump lubrication system uses a remote oil tank reservoir positioned in front of the engine. This compact oil tank features a partition in the centre of the tank that improves the air-oil separation function. This tank is positioned low in the chassis which centralizes mass and lowers the centre of gravity for exceptional handling and a light feeling.
Oil volume in the engine has been optimized to reduce weight and "oil drag" related power losses.
5-speed transmission features "involute splines" on the transmission axles to ensure smooth shifting and instant hook-up under power.
Multi-plate wet clutch provides an easy clutch lever pull.
Lightweight, "quick-access" outer clutch cover provides fast, easy access for clutch maintenance.
Compact automatic cam chain tensioner reduces maintenance and mechanical engine noise
New, larger Keihin FCR-MX39 flat-slide carburetor with throttle position sensor (TPS) and an accelerator pump for excellent throttle response. The carb bore has been increased from 37mm (2011) to 39mm for improved engine performance and less intake airflow resistance. The diameter of the intake boot has also been increased to match the new carb.
The revised air box features a straight design "boot" between the air box and the carb for optimum air flow. The air cleaner holder or guide has been modified for less intake airflow resistance for improved performance.
Washable, dual-stage, foam air filter.
No fuss auto decompression system means fast, easy starting. The YZ250F restarts in any gear.
Convenient, handlebar-mounted hot start lever ensures fast starts when the engine is hot.
CD ignition system delivers a strong, precise spark and monitors engine rpm to insure optimal timing for fast, strong response at all rpms.
Direct ignition system means the ignition coil is integrated into spark plug cap to reduce weight and complexity.
Compact, lightweight, single core, dual radiators provide outstanding cooling efficiency. The location of the rads has been optimized for maximum airflow and protection in the event of a crash, plus they help reduce the center of gravity and centralize mass too.
Lightweight titanium exhaust header pipe minimizes weight, improves performance and allows hassle-free replacement of the oil filter.
The lightweight exhaust system utilizes a 4-stage expansion format that improves the cylinder filling induced by the exhaust pulse effect, resulting in excellent power characteristics.
Revised muffler assembly features an internal diffuser pipe and noise reducing "punched hole pipe" to achieve maximum performance with reduced noise levels. The muffler can be repacked to maintain peak performance. The sound "deadening" material now extends into the newly designed tapered end cone of the muffler for a further reduction in noise.
Works-style race-spec "barrel adjuster" for on-the-fly clutch lever free play adjustments.
CHASSIS / SUSPENSION
Revised, compact "bilateral beam" aluminum frame centralizes mass for exceptional handling and cornering ability. The frame consists of forged, extruded and panel aluminum parts. The revised frame features new tank rails (or top rails) which utilize 3 internal box sections instead of 2. The swingarm pivot area has also been modified for improved handling performance. The longitudinal and torsional rigidity balance of the frame has been modified and optimized for improved handling and a light, agile feel. The benefit of this revised chassis is fast, easy cornering … one of the most important keys to winning races.
The front and upper rear engine mounting brackets have been revised and strengthen the engine\'s function as a stressed member of the chassis.
The head pipe (steering head), wheelbase, caster and trail dimensions are optimized to accentuate the engine and frame characteristics. The benefit is incredible turning ability and quick, stable handling.
Removable rear sub frame is constructed of square-section, lightweight aluminum pipe. Its detachable design allows easy access when servicing rear suspension components.
Revised lightweight, tapered, aluminum swingarm is produced using "hydro forming", a special method that uses high pressure water to form shapes. The swingarm design provides great overall "balance" with the frame for precise cornering, excellent traction and a light handling feel. The end portion (chain adjuster area) has been modified and the rigidity increased.
Cast aluminum upper and forged aluminum lower triple clamps. The new cast upper clamp features a 50% increase in rigidity for improved handling.
Fork offset has been decreased from 25mm to a 22mm offset. This increases the trail dimension and provides excellent stability.
Revised 48mm, adjustable, inverted, Kayaba, "Speed Sensitive", cartridge fork features a twin-chamber design, meaning the damper unit is in a separate structure which prevents aerated fork oil from entering the inner damper assembly and degrading its damping abilities. Since the inner damper is pressurized, it also prevents air bubbles forming in the oil.
For 2012 the fork modifications include a weight reduction to the internal cylinder head, tank and spring guide (these are fork internals … not engine internals). The outer tube shape is revised and is now the same as the YZ450F
Front fork adjustments include: 20-way compression damping and 20-way rebound damping. Optional fork springs are available through Genuine Yamaha parts.
The 48mm inverted KYB fork also features a Transfer Control Valve (TCV) system. The TCV enhances the damping force of the inner damper from mid stroke to full stroke and improves bottoming characteristics. The benefit of TCV is more precise control throughout the full stroke. The TCV is located on the upside of the spring and its function is controlled by piston speed, not piston position … hence the term "Speed Sensitive fork".
Front and rear suspension settings have been modified to accentuate the engine and frame changes.
The combined benefits of the revised frame, fork and fork offset provides less front - rear pitching and excellent stability when exiting a corner.
Front wheel travel is 300mm or 11.8"
Large "wrap-around" plastic fork protectors provide excellent lower fork tube protection. The "self-supporting" design reduces friction for smoother fork operation.
Revised Monocross link rear suspension system features a fully adjustable Kayaba, piggyback shock which features separate adjusters for high- and low-speed compression damping. Adjustments include: spring preload, 20-way rebound damping, 20-way low-speed compression damping and 2 turns of high speed compression damping.
The revised shock uses a new 16mm diameter piston rod. Kashima coating is used in the shock body and sub tank to reduce friction and improve suspension performance during a long moto. The Kayaba shock utilizes a full rebound oil lock system for excellent suspension function and great ride quality.
Rear wheel travel has increased from 307mm (12.1") to 317mm (12.5").
250mm floating front wave-style disc reduces weight and improves heat dissipation. It is squeezed by a compact Nissin twin piston caliper.
245mm rear disc brake features a lightweight "wave-style" disc and a single piston Nissin caliper.
Compact, lightweight rear master cylinder is an integrated design (fluid reservoir is integrated into the top of the master cylinder) for strong stopping power with excellent feel and control.
Pro Taper handlebar provides excellent strength and durability. Foam handlebar pad is included.
Adjustable handlebar clamps offer a total of 4 different handlebar positions with an adjustment range of 30mm, to suit a wide variety of riders.
Eye catching, compact body work enhances the lightweight feel and look of the YZ250F. This "minimal" bodywork is a flat design, allowing fast, easy rider movements. The ergonomics provide a natural and roomy riding position. The body has been designed to maintain it good looks throughout the life of the machine.
The lightweight, plastic resin 6.4 litre fuel tank compliments the chassis and its location helps to centralization tank mass. Its compact design allows excellent rider mobility.
Revised seat material reduces weight and improves rider comfort. The seat surface texture has been designed to give a grip when needed, yet still allow easy rider movements. The seat cover resists clogging with dirt or mud to ensure long lasting good looks.
Lightweight, 21" front and 19" rear Excel rims provide exceptional durability and help reduce unsprung weight for optimal suspension performance and handling.
Rear wheel assembly uses a large 25mm diameter axle and the rear hub features a second bearing on the sprocket side for increased rigidity and durability.
Lightweight Sun Star rear sprocket.
ADDITIONAL DETAILS / FEATURES
Rugged polypropylene engine and integrated water pump protector plate reduces weight.
"Shorty" adjustable front brake lever. Adjustment range is 5.5mm.
New throttle tube design provides improves throttle feeling and response
Convenient oil sight glass window
Heavy duty plastic rear caliper and lower rear disc protectors.
Lightweight, extra wide foot pegs excellent grip
Lightweight header pipe heat shield.
Serrated rear brake pedal for extra grip
Folding gear shifter tip
Stainless steel inner clutch cable provides excellent strength and durability.
Lightweight chain guide / support helps reduce chance of chain derailment and also helps protect the rear sprocket.
Heavy duty DID 520 drive chain
E10 friendly fuel system components
2012 Yamaha YZ250F - Specifications/Technical Details
Type 250cc liquid-cooled DOHC 4-stroke; 5 titanium valves
Bore x Stroke 77.0mm x 53.6mm
Compression Ratio 13.5:1
Fuel Delivery Keihin® FCR MX39
Transmission Constant-mesh 5-speed; multiplate wet clutch
Final Drive Chain Drive
Suspension / Front KYB® Speed-Sensitive System, inverted fork: fully adjustable, 11.8-in travel
Suspension / Rear KYB® Fully adjustable single shock; 12.5-in travel
Brakes / Front Hydraulic single disc brake, 250mm
Brakes / Rear Hydraulic single disc brake, 245mm
Tires / Front 80/100-21
Tires / Rear 100/90-19
Length 85.4 in
Width 32.5 in
Height 51.4 in
Seat Height 39.0 in
Wheelbase 58.1 in
Ground Clearance 14.9 in
Fuel Capacity 1.6 gal
Wet Weight*** 227 lb