Overview Model: Yamaha YZ250 (two-stroke motocross competition bike) Engine: 249?cc liquid-cooled reed-valve two-stroke with Yamaha Power Valve System (YPVS), fueled by a 38?mm Hitachi Astemo Keihin PWK38S carburetor  Powerband: Crisp bottom and mid-range response with strong top-end punch  Specs & Features Engine & Drivetrain Bore × Stroke: 66.4?mm × 72?mm Compression Ratio: 8.9 – 10.6:1 Transmission: 5-speed constant-mesh manual gearbox Final Drive: Chain  Suspension & Chassis Front Suspension: 48?mm KYB Speed-Sensitive inverted fork, fully adjustable – 11.8 in (300?mm) travel Rear Suspension: KYB single shock with Kashima coating and separate high-/low-speed compression adjustment – 12.4 in (315?mm) travel Frame: Lightweight aluminum chassis and removable subframe Brakes: 270?mm front disc, 240?mm rear disc hydraulic brakes Wheels/Tires: Excel rims with front 80/100-21 & rear 110/90-19 Dunlop Geomax MX33 tires  Dimensions & Ergonomics Wet Weight: Approximately 227?lb (including fluids & full fuel) Seat Height: ~38.4 in Wheelbase: 58.5 in Dimensions: 86?in (L) × 32.5?in (W) × 50.8?in (H) Ground Clearance: About 14.2 in