Midwest Track & Training Reviews
2025 Yamaha YZ250FX
Owner’s Spec & Maintenance Reference
250cc 4-stroke
A verified reference compiled by MWR — not a reproduction of the factory manual.
1Full Specifications
| Displacement | 250 cc |
|---|---|
| Bore × stroke | 77 × 53.6 mm |
| Cooling | Not documented |
| Induction | Mikuni fuel injection, 44mm |
| Power valve | Not documented |
| Starter | Not documented |
| Transmission | 6-speed |
| Clutch | Not documented |
| Final drive | Chain |
| Front suspension | KYB spring-type fork with speed sensitive damping; fully adjustable |
|---|---|
| Front travel | 11.8 in |
| Rear suspension | KYB single shock |
| Rear travel | 12 in |
| Front brake | 270 mm |
| Rear brake | 240 mm |
| Front tire | 80/100-21 Dunlop Geomax MX33F |
| Rear tire | 110/100-18 Dunlop Geomax MX33 |
| Seat height | 37.6 in |
|---|---|
| Wheelbase | 57.9 in |
| Ground clearance | 13 in |
| Weight | 243 lb (Wet weight*** includes the vehicle with all standard equipment and all fluids, including oil, coolant (as applicable) and a full tank of fuel. It does not include the weight of options or accessories.) |
| Fuel capacity | 2.1 gal |
| Fuel / premix | Unleaded (4-stroke) |
| MSRP (new) | Not documented |
2Fluids & Capacities
Safety-critical — published only from the service/owner’s manual for this exact year-model. Always confirm against your manual before service.
Not documented from the service manual for this year — consult the factory manual.
3Torque Specifications
Safety-critical — listed only as published in the service manual for this exact year-model. Use a calibrated torque wrench.
Not documented from the service manual for this year — consult the factory manual.
4Maintenance Schedule
Guideline intervals — they vary by year and how hard the bike is ridden. Confirm exact figures in your owner’s manual.
| Service item | Interval | Notes |
|---|---|---|
| Air filter — clean or replace | every ride | Do this basically every ride. A clogged filter chokes power; a torn one lets grit into the engine. |
| Engine oil & oil filter | ~every 10 h | Fresh oil protects the whole motor. Hard riders change it often — many every few hours of race time. |
| Top-end / piston check | ~every 80 h | The piston and rings wear out. Replacing on time prevents a far more expensive bottom-end failure. (2-strokes need it much sooner than 4-strokes — check your manual.) |
| Valve clearance check | ~every 25 h | Four-stroke valves tighten over time and can burn if ignored. Checking is cheap; a new head isn’t. |
| Spark plug | ~every 30 h | A fresh plug means easy starts and clean running. Cheap insurance. |
| Chain & sprockets | ~every 40 h | A worn chain and sprockets rob power and can snap. Replace as a set. |
| Coolant | ~every 50 h | Fresh coolant stops overheating and corrosion. Roughly once a season for most riders. |
| Grease linkage & bearings | ~every 20 h | Re-greasing the suspension linkage and wheel bearings keeps the bike handling right and saves bearings. |
5Known Issues & Fixes
No verified year-specific issues documented yet.
6Common Upgrades
Not documented yet.
7Owner Tips
Not documented yet.
9Official Manuals
No verified factory manual linked for this year yet — always service to your model-year service manual.