2003 YZ250F Information






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Back-to-back 125 Supercross Championships**. Three "125 of the Year" crowns*** in just two seasons. And now a machine that's even better. Presenting the 2003 YZ250F four-stroke. Poked and prodded from nose to tail, this quarter-liter wonder-bike has been fine-tuned to the tiniest detail, starting with all-new bodywork and styling that creates an even more aggressive riding position while allowing maximum rider movement.

Screaming-fast revs, lightning-quick throttle response and potent low-rev torque are three of the high-performance perks served up by the YZ250F's exclusive 5-valve cylinder head technology. An all-new frame boasts lighter-weight and greater lateral rigidity for sharper handling with minimal flex. Thoroughly retooled suspension coupled with a lighter swingarm delivers more compliant, stiction-free damping action for smoother handling. And all-new front and rear disc brake componentry ensures even stronger, more progressive stopping power. The YZ250F. Bring on the competition.

"As it sits, the YZ250F is the best 125 motocross bike built. If you can have only one bike in your garage - this is the one." MOTOCROSS ACTION.

Manufacturer's Suggested Retail Price...$5,599

  • '01 125 SX West Regional

  • '02 125 SX East Regional

  • MXA, '01, '02

  • Dirt Rider, '01




NEW FOR 2003

  • The industry's most powerful and most advanced 250cc 4-stroke MX machine returns lighter and better handling than ever!
  • All-new automatic decompression system eliminates manual lever, ensuring easy restarts in any gear.
  • All-new hot start system features convenient, handlebar-mounted lever.
  • Redesigned airbox features all-new retaining bracket for improved sealing.
  • Super-strong frame redesigned with reduced weight and greater lateral rigidity for minimal flex and scalpel-sharp handling.
  • All-new tapered swingarm features less weight and greater rigidity for more compliant rear suspension action.
  • Recalibrated front fork settings deliver improved damping force with less bottoming for a smoother, more compliant overall stroke.
  • Rear shock refinements include improved actuation, a new linking ratio and enhanced damping force.
  • Removable aluminum rear subframe redesign, reduces weight and allows for easy maintenance.
  • All-new, lighter-weight front and rear master cylinders and calipers, combined with 250mm fully floating front and 245mm rear disc, delivers stronger stopping power with greater, more progressive control and feel.
  • Retooled steering crown combines with all-new bodywork - flatter seat, fuel tank and radiator shrouds - creates a more aggressive riding position while allowing optimal rider movement.
  • More weight reduction via all-new, two-piece (part aluminum, part plastic) engine protector plates and thinner-walled engine guard construction.


  • Liquid-cooled, 249cc, 5-valve, DOHC, 4-stroke is the world's most powerful, quarter-liter 4-stroke motocrosser with a stratospherically high, 13,500-rpm redline means incomparable, competition-crushing pulling power.
  • Titanium valves and load-reduced springs decrease weight by more than 40% and reduce reciprocating mass for faster-revving, harder-hitting power delivery across the rev range.
  • Lightweight forged piston reduces reciprocal mass and friction for faster revving and greater durability.
  • Slick-shifting, 5-speed transmission with heavy-duty, multi-plate clutch features an involute spline set-up, ensuring smoother shifting and instant hook-up under power.
  • 37mm Keihin FCR flat-slide carburetor with throttle position sensor (TPS) ensures ultra-precise fuel/air mixing and lightning-quick throttle response.
  • Digital CD ignition system delivers more precise spark and monitors engine speed to ensure optimal timing for faster, stronger response during hard acceleration.
  • Large-capacity radiator provides outstanding cooling efficiency.
  • Lightweight exhaust system with specially shaped header angle maximizes engine power and allows hassle-free replacement of oil filter.
  • Aluminum exhaust silencer looks trick and reduces weight.
  • Primary kickstarting (with all-new automatic decompression and hot start lever) ensures easy restarts.
  • Dry sump lubrication system uses frame as oil tank, helping to create a more compact engine and chassis for superb handling performance.
  • Magnesium cylinder head cover helps shave weight.
  • Trick, works-style clutch lever features race-spec barrel adjuster for on-the-fly adjustability.


  • Removable aluminum rear subframe constructed of square-section pipe for reduced weight.
  • Lightweight 46mm inverted Kayaba cartridge fork features 11.8" of travel with compression and rebound adjustability.
  • Low-friction outer tubes and aluminum piston rods ensure smooth, compliant fork stroke for superior handling and light steering.
  • Rear suspension system features fully adjustable Kayaba shock with 12.4" of travel and separate adjusters for high- and low-speed compression damping.
  • Lightweight 21" front and 19" rear rims provide exceptional durability and help reduce unsprung weight for optimal suspension performance.
  • Premium Dunlop 739 knobbies offer unbeatable, competition-spec traction and excellent wear.

Additional Features

  • Wide, cleated, folding cast alloy footpegs provide excellent comfort, grip and ground clearance.
  • Cleated rear brake lever and folding shift lever tip offer superb grip and excellent durability.
  • Repackable exhaust silencer.
  • Durable, comfortable handlebar grips.
  • Stainless steel clutch cable for longer life


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MSRP $5,599* Available from September 2002
Type 249cc, liquid-cooled, 5-valve, DOHC, 4-stroke w/titanium valves
Bore x Stroke 77 x 53.6mm
Compression Ratio 12.5:1
Carburetion 37mm Keihin FCR flat-slide w/throttle position sensor
Ignition Digital CDI
Transmission 5-speed w/multi-plate wet clutch
Final Drive #520 Chain
Suspension/Front 46mm Kayaba inverted telescopic fork w/adjustable compression and rebound damping; 11.8 " travel
Suspension/Rear Fully adjustable Kayaba single shock, 12.4" travel; separate hi/lo speed compression adjustment
Brakes/Front 250mm Floating Disc
Brakes/Rear 245mm Disc
Tires/Front 80/100-21 Dunlop
Tires/Rear 100/90-19 Dunlop
Length 85.1"
Width 32.5"
Height 51.2"
Seat Height 39.2"
Wheelbase 58.0"
Ground Clearance 15.0"
Dry Weight N/A
Fuel Capacity 1.8 Gallons
Main Jet #178
Main Air Jet #200
Jet Needle 0BELP-4
Needle Jet 2.9mm (I.D.)
Pilot Air Jet 1 #100
Pilot Outlet 0.9
Pilot Jet #40
Primary Reduction Ratio 57/17 (3.353)
Secondary Reduction Ratio 48/13 (3.692)
Gear Ratio - 1st Gear 30/14 (2.143)
Gear Ratio - 2nd Gear 28/16 (1.750)
Gear Ratio - 3rd Gear 29/20 (1.450)
Gear Ratio - 4th Gear 27/22 (1.227)
Gear Ratio - 5th Gear 25/24 (1.042)
Gear Ratio - 6th Gear Not Applicable
Color Team Yamaha Blue/White
Warranty 30 Day (Limited Factory Warranty)




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Last Updated 11/01/2003