2013 Yamaha YZ250
General Specifications
| Model | Yamaha YZ250 |
| Year | 2013 |
| Category | Motocross / Competition Off-Road |
| Engine Type | Liquid-cooled, single-cylinder, 2-stroke, piston reed-valve induction with Yamaha Power Valve System (YPVS) |
| Weight | 103 kg (227 lb) wet / curb weight |
Engine
| Displacement | 249 cc |
| Bore x Stroke | 66.4 x 72.0 mm |
| Compression Ratio | 8.9–10.6:1 (effective compression varies with exhaust-port timing) |
| Fuel System | Keihin PWK38S, 38 mm flat-slide carburettor with reed-valve induction | Replacement Options |
| Ignition | CDI magneto ignition |
| Spark Plug | NGK BR8EG (resistor type) |
| Spark Plug Gap | 0.5–0.6 mm (0.020–0.024 in) |
| Cooling System | Liquid-cooled, twin radiators; coolant capacity approximately 1.20 L |
| Starting System | Kick starter |
Transmission
| Transmission | 5-speed constant-mesh manual |
| Clutch | Wet, multi-plate, cable-operated |
| Final Drive | Chain drive; standard gearing 14T front / 50T rear (3.571:1) |
Dimensions
| Overall Length | 2,179 mm |
| Overall Width | 827 mm |
| Overall Height | 1,307 mm |
| Wheelbase | 1,481 mm |
| Ground Clearance | 382 mm |
| Seat Height | 994 mm |
| Fuel Capacity | 8.0 litres |
Chassis
Suspension
| Front Suspension | 48 mm KYB upside-down Speed Sensitive System (SSS) twin-chamber cartridge forks, adjustable compression and rebound damping | Fork Oil Levels |
| Front Suspension Travel | 300 mm (11.8 in) |
| Rear Suspension | KYB gas/oil-damped Monocross linkage shock with adjustable spring preload, compression and rebound damping |
| Rear Suspension Travel | 315 mm (12.4 in) |
| Fork Oil | Yamaha Suspension Oil S1. KYB twin-chamber forks: inner damper approximately 205 mL per leg; outer chamber approximately 330 mL per leg, with quantity adjustable for suspension tuning. Inner and outer chamber quantities are separate. Confirm exact filling quantities against the applicable regional service manual and fork assembly. |
Brakes & Wheels
| Front Brake | Hydraulic single disc, 250 mm rotor, twin-piston caliper |
| Rear Brake | Hydraulic single disc, 245 mm rotor, single-piston caliper |
| Front Wheel Size | 21 x 1.60-inch aluminium spoked rim |
| Rear Wheel Size | 19 x 2.15-inch aluminium spoked rim |
Service Data
| Fuel Type | Premium unleaded petrol, minimum 95 RON, mixed with suitable 2-stroke oil |
| Premix Information | 30:1 petrol-to-oil ratio using Yamaha Yamalube 2-R or suitable equivalent 2-stroke oil. Approximately 33.3 mL oil per litre of petrol | Premix Calculator |
| Gearbox Oil | Yamalube SAE 10W-40, API SG or higher, JASO MA. Periodic transmission oil change: 0.75 L (750 mL). Total transmission oil capacity: 0.80 L (800 mL). |
| Air Filter | Reusable, oil-treated foam air-filter element |
| Service Notes | The 2013 YZ250 was mechanically carried over from the preceding model, with minor cosmetic revisions in some markets. Maintain the specified 30:1 premix ratio and ensure carburettor jetting suits local temperature, altitude and fuel. Inspect piston, piston rings, reed valves and YPVS operation according to racing hours and operating conditions. Spark plug tightening torque: 20 Nm. Regularly clean and oil the foam air filter, change transmission oil and inspect coolant, chain tension, brake pads and spoke tension. Check fork seals, suspension linkage bearings, steering-head bearings and wheel bearings. Regional equipment, graphics and carburettor settings may differ. |
2013 Yamaha YZ250 – Keeping the Two-Stroke Tradition Alive
The 2013 Yamaha YZ250 continued one of motocross racing's longest-running and most successful two-stroke designs. While four-stroke motorcycles dominated professional racing and manufacturer development budgets, Yamaha maintained its commitment to the 249cc two-stroke. The 2013 model was essentially a continuation of the previous year's motorcycle, with minor cosmetic revisions rather than significant mechanical changes.
Much of the YZ250's reputation came from engineering introduced years earlier. Its aluminium frame had arrived in 2005, followed by the highly regarded Kayaba Speed Sensitive System suspension in 2006. By
