2008 Yamaha YZ250F

– 2008 Yamaha YZ250F

2008 Yamaha YZ250F

YZ250F… choosing the YZ250F is the easy part.

The 2008 Yamaha YZ250F is one of the most popular and durable MX2 rides in the business. Its combination of a powerful easy to use engine and a chassis characterized by outstanding handling and stability make the 2008 YZ250F a winner right out of the bix. For 2008 we have taken it to the next level with a new piston for increased compression, a revised clutch for improved durability and as always, we’ve improved the syspension too.

Blitz faster, scrub flatter and dive deeper. Now more than evr, you are lookingat the most highly refined, sweetest-handling, easiest to ride quarter liter motocrosser money can buy.

The epitome of quarter liter, free-revving four-stroke performance, the 2008 YZ250F gets a handful of key changes to keep it at the front of the pack.

Ongoing refinements to the engine and chassis produce an amazingly balanced, light handling machine with performance that’s accessible to all level of riders. A new piston, new ignition mapping, and new lighter front fork … improvements designed to help you find the “holy grail”… a.k.a. the top step of the podium.

FEATURES:

Revised liquid-cooled, 249cc, DOHC, 5-titanium valve, 4-stroke engine features a 13,500-rpm redline for incomparable, competition-crushing power.

All new design short skirt forged piston increases compression from 12.5 to 13.5:1 for 2008. The increased compression maximizes the 5-valve combustion chamber design allowing for faster combustion and improved engine performance.

Optimized combustion chamber design provides the most efficient intake flow for maximum power.

Titanium valves and load-reduced springs decrease weight by more than 40% over a conventional valve train and reduce reciprocating mass for faster-revving, smoother-hitting power delivery across the rev range.

The cylinder features a ceramic composite coating which insures faster, more uniform heat dissipation, reduced friction and a longer service life.

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.”

Lightweight crankcase also utilizes special cutaways to reduce “pumping losses.” The crankcase cutaways match the cutaways in the cylinder for maximum efficiency.

Magnesium cylinder head cover helps reduce weight.

Dry sump lubrication system uses an oil tank reservoir positioned just in front of the engine. The 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.

Slick-shifting, 5-speed transmission features involute splines on the transmission axles, ensuring smooth shifting and instant hook-up under power.

Optimized backlash clearances between the drive, driven gears and balancer gears reduce mechanical noise. Backlash is the small “gap or clearance” between meshing gears.

Lightweight balancer shaft reduces vibration for improved rider comfort and less rider fatigue.

Revised clutch features a new oil passage and optimized oil supply to both the friction and steel plates for improved reliability. Friction plate design and material have been modified for improved durability.

Lightweight, magnesium “quick-access” outer clutch cover provides fast access for clutch maintenance.

Compact design automatic cam chain tensioner reduces maintenance and mechanical engine noise

Revised Keihin FCR-MX37 flat-slide carburetor with throttle position sensor (TPS) ensures ultra-precise fuel/air mixing and lightning-quick throttle response. The 2008 carb features revised settings to accommodate the increased compression ratio and improved power output.

Automatic decompression system means easy starting. The YZ250F restarts in any gear.

Convenient, handlebar-mounted hot start lever ensures fast starts when the engine is hot.

Washable, dual-stage, foam air filter provides excellent filtering qualities.

Revised CD ignition system delivers a precise spark and monitors engine speed to ensure optimal timing for faster, stronger response at all rpms. The CD settings have been improved for 2008 to match the engine improvements.

Ignition coil is integrated into spark plug cap to reduce weight and complexity.

Compact, lightweight, single core, dual radiators provide outstanding cooling efficiency. Reinforcing bars provide protection in the event of a tip over.

Lightweight titanium exhaust header pipe and heat shield reduce weight. Specially shaped header pipe angle maximizes engine power and allows hassle-free replacement of the oil filter.

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. The muffler can be repacked to maximize power and maintain noise limits. The lightweight aluminum / stainless steel muffler complies with current CMRC & AMA noise regulations.

Trick, works-style clutch lever features a race-spec “barrel adjuster” for on-the-fly adjustability.

Compact aluminum semi-double-cradle frame features a cast steering head while the remainder of the frame uses forged, pipe stock and extruded components. Yamaha has maintained the semi double cradle design to allow for “controlled flex” to optimize suspension action. This frame design provides a lower centre of gravity for a light feel and razor sharp handling, plus less rider fatigue, and excellent stability.

Removable rear subframe 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 forming method that uses high pressure water to form shapes. The revised swingarm features a change to the chain adjuster area of the arm to reduce weight. The swingarm improves overall chassis balance for a lighter handling feel.

New, forged aluminum upper triple clamp reduces weight by 17% over last year’s cast version. The reinforcing ribs have also been modified for improved strength and reduced weight. The handlebar holder has also been revised for reduced weight.

New forged aluminum lower triple clamp has been revised to improve the overall rigidity balance. It shape is now an “H” shape in the cross section plane.

Lightweight, forged aluminum adjustable handlebar mounts allow the handlebars to be moved 10mm rearward if desired.

Pro Taper handlebars are one of the most sought after style of bars and are stock items on Yamaha’s big YZ motocross models. The Pro Taper bars provide excellent strength and durability. Foam handlebar pad is included.

Revised 48mm, adjustable, inverted, Kayaba cartridge forks feature a twin-chamber design. The twin chamber design means 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 eliminates bubbles forming in the oil.

The balance between the inner and outer tubes is optimized, while the Kashima coating on the pressure tank and the piston rod reduce friction for smoother suspension performance. The cylinder diameter is 24mm for excellent primary cushioning.

The design of the outer tube below the fork seal has been revised to reduce weight. Low friction oil seals are used to reduce stiction. The compression valve port is lager and the slide clearances to the bushings have been revised to reduce friction and improve damping.

The 48mm inverted KYB fork also features a Transfer Control Valve (TCV). 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 range. 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”.

“Kashima coating” has been applied to the fork tubes to reduce friction for smoother suspension performance. Front wheel travel is 300mm (11.8″).

Front fork adjustments include: 20-way compression damping and 20-way rebound damping. Optional fork springs are available through Genuine Yamaha parts.

New design “wrap-around” plastic fork protectors provide excellent protection from dirt, mud and stone chips. The “self-supporting” design reduces friction for smoother fork operation. The lower axle brackets have been revised to accommodate the new protectors.

Revised Monocross link rear suspension system features a fully adjustable Kayaba, piggyback shock which provides 306mm (12″) of wheel travel and 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 shock features a new larger compression valve port for improved damping performance. The piston rod diameter is 18mm and 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.

Lightweight and trick “Beta” titanium shock spring reduces “unsprung weight” which has a dramatic effect on suspension performance. This titanium spring provides outstanding strength, and durability, combined with reduced weight

The rear linkage lever ratio and lower rear pivot shaft and collar diameters have been revised for improved suspension performance and reduced weight.

250mm floating front disc brake system utilizes a lightweight “wave-style” rotor to reduce weight.

Twin piston front brake caliper utilizes aluminum pistons to reduce weight. It features a revised “shorty style” adjustable front brake lever with an increased lever range.

245mm rear disc brake features a lightweight “wave-style rotor. The rotor (disc) is squeezed by a single piston caliper. The 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. Rear brake pads have been revised for 2008

The rear caliper and the lower portion of the wave rotor are protected by heavy duty plastic protectors.

New design rear brake lever provides excellent feel

“Slim line” body components include: front and rear fenders, rad shrouds, side covers /number plates, gas tank and seat. This body design not only provides an aggressive appearance to the YZ250F but also allows for fast, easy rider movements.

Specially designed “Sun Star” rear sprocket increases the contact area between the sprocket and chain rollers, thereby reducing the load on the chain and increasing the service life of both chain and sprocket.

Lightweight, 21″ front and 19″ rear Excel rims provide exceptional durability and help reduce unsprung weight for optimal suspension performance and handling.

New Bridgestone knobby tires offer competition-spec traction and excellent wear.

Compact engine protector plate offers excellent protection.

“Flat-design” seat features a dual foam design that provides good initial softness / comfort and then increases the firmness as more pressure is applied. The “pebble or “gripper” finish on the top and side surfaces provides excellent rider grip and durability.

Large fuel cap and filler hole ensures easy opening and fast, hassle-free refueling.

New lightweight, extra wide foot pegs provide excellent grip and ground clearance. The 2008 pegs are 10mm wider than last year’s version

Cleated, rear brake lever and folding shift lever tip offer superb grip and exceptional durability.

Stainless steel, inner clutch cable provides excellent strength and long life.

Rugged engine and water pump protector plates.

7 liter fuel tank

Lightweight chain guide / support helps reduce chance of chain derailment. Also helps protect rear sprocket damage too.

Heavy duty rubber swingarm protector

SPECIFICATIONS USA – 2008 Yamaha YZ250F:
MSRP* $6,249 (Team Yamaha Blue/White) Available from June 2007
$6,349 (White/Red) Available from June 2007


Engine
Type 250cc liquid-cooled DOHC 4-stroke; 5 titanium valves

Bore x Stroke 77.0mm x 53.6mm

Compression Ratio 13.5:1

Carburetion FCR-MX37 x 1

Ignition CDI

Transmission Constant-mesh 5-speed; multiplate wet clutch

Final Drive Chain Drive


Chassis
Suspension/Front Speed-Sensitive System inverted fork; fully adjustable, 11.8-in travel

Suspension/Rear Fully adjustable single shock; 12.0-in travel

Brakes/Front Hydraulic single disc brake, 250mm

Brakes/Rear Hydraulic single disc brake, 245mm

Tires/Front 80/100-21-51M

Tires/Rear 100/90-19-57M


Dimensions
Length 85.1 in

Width 32.5 in

Height 51.2 in

Seat Height 38.8 in

Wheelbase 57.8 in

Ground Clearance 14.6 in

Dry Weight 204 lb

Fuel Capacity 1.8 gal


Other
Warranty 30 Day (Limited Factory Warranty)

SPECIFICATIONS Canada – 2008 Yamaha YZ250F:
Suggested Retail $7,949 CDN

Engine 4-stroke, liquid-cooled, DOHC, 5-valve (titanium), single
Displacement 249 cc
Bore and Stroke 77 x 53.6 mm
Compression Ratio 13.5:1
Maximum Torque 3.0 kg-m (21.7 ft-lb) @ 8,500 rpm
Fuel Delivery Keihin FCR MX37, flat-slide w/throttle position sensor
Ignition CDI
Transmission 5-speed
Final Drive Chain

Suspension (Front) Fully Adjustable 48 mm inverted fork; 300 mm (11.8″) travel
Suspension (Rear) Fully adjustable link Monocross; 306 mm (12″) travel
Brakes (Front) 250 mm floating disc
Brakes (Rear) 245 mm disc
Tires (Front) 80/100-21
Tires (Rear) 100/90-19

Length 2,162 mm (85″)
Width 825 mm (32.5″)
Height 1,300 mm (51.1″)
Wheelbase 1,469 mm (57.8″)
Ground Clearance 370mm (14.6″)
Seat Height 985 mm (38.7″)
Dry Weight 92.7 kg (203.9 lb)
Fuel Capacity 7 litres (1.6 imp. gallons)
Colour(s) Yamaha Blue; White

Specifications and features are subject to change