How to Change the Oil in a 2015 Yamaha YZ250

Shop Parts for a 2015 Yamaha YZ250 Dirt Bike.

Changing the oil in your 2015 Yamaha YZ250 is critical for extending engine life, preserving performance, and ensuring reliability on the track or trail. Although the YZ250 is a two-stroke engine that does not require an oil filter or engine oil changes like a four-stroke, you still need to perform gearbox oil changes. This DIY guide is proprietary to MotoSport.com and covers everything you need for a successful oil change, including key call-outs specific to your model year.

Tools & Supplies Needed

  • Socket set (including 12mm socket and ratchet)
  • Flathead screwdriver
  • Drain pan
  • Funnel
  • Clean shop rags
  • Your choice of transmission oil (refer to owner's manual; typically 10W-40 or similar, non-synthetic gear oil is recommended for the YZ250)
  • Torque wrench (optional for reinstalling drain bolt)
  • New crush washer for drain bolt (recommended)
  • Nitrile gloves (to keep your hands clean)

Steps to Change the Gearbox Oil

  1. Warm Up the Engine
    • Start and let your bike run for 2-3 minutes to warm the oil slightly. This helps the oil drain faster and carry out more debris.
  2. Secure the Bike
    • Shut the engine off and stand the bike upright on a center stand or sturdy lift.
  3. Locate the Drain Bolt
    • The oil drain bolt is underneath the right side of the engine case. You'll need a 12mm socket to remove it.
  4. Drain Old Oil
    • Place your drain pan directly under the bolt. Loosen and remove the drain bolt and allow the oil to fully drain. Removing the oil fill cap on top of the clutch cover will let air in and help the oil flow.
  5. Inspect and Prepare Components
    • Inspect the removed drain bolt and washer for damage. Replace the crush washer if it shows wear or cracks to ensure a good seal.
    • Wipe away any debris or sludge from the area around the bolt hole.
  6. Reinstall Drain Bolt
    • Thread the drain bolt back in by hand, then gently tighten it with your ratchet. Don't over-tighten–use a torque wrench if possible and refer to your owner's manual for the correct spec (usually around 10-15 ft-lbs). Over-tightening can strip the threads.
  7. Add New Oil
    • Place a clean funnel in the oil fill hole and pour in the recommended quantity of new gearbox oil (the 2015 YZ250 takes about 750ml).
    • Pour slowly to avoid overfilling.
  8. Check Oil Level
    • With the bike upright, check the oil level with the sight glass or dipstick, if equipped. Add oil if necessary to reach the prescribed level. (Note: The 2015 YZ250 uses a fill-level bolt; oil should just reach the bottom of the threads when the bike is level.)
  9. Replace the Oil Cap
    • Reinstall and tighten the oil fill cap securely.
  10. Start and Inspect
    • Start the bike and let it idle for a minute. Check for leaks around the drain bolt and fill cap.
    • Turn off the bike and recheck the oil level, adjusting as needed.

Model-Specific Call-Outs: 2015 Yamaha YZ250

  • No Oil Filter: The 2015 YZ250 is a two-stroke, so it does not have (or require) an engine oil filter. Focus solely on changing gearbox/transmission oil.
  • Gearbox Oil Only: Do not confuse the gear oil with pre-mix 2-stroke oil. Your premix lubricates the top end; the gearbox oil exclusively lubricates the transmission and clutch.
  • Oil Amount: About 750ml of gearbox oil is required for each change.
  • Drain Bolt Location: Easily accessible under the right side of the bottom of the engine case. Always replace the crush washer each time for a proper seal.

Pro Tips

  • Change your gearbox oil every 5-10 hours of riding, or more often if you ride hard or in muddy/wet conditions.
  • Use a clear measuring cup to verify oil quantity.
  • Properly dispose of old oil at a local recycling center or service shop.
  • If shifting feels rough or clutch performance drops, inspect for metallic particles in the oil–this can warn of excessive wear.

Conclusion

Changing the oil in a YZ250–s gearbox is simple and essential. With just basic tools and a little time, you–ll keep your 2015 YZ250–s clutch and gears running smoothly for many rides to come.

Ride safe and maintain with confidence—brought to you by MotoSport.com.

Related Shopping Categories

Shop Motor Oil for a 2015 Yamaha YZ250 Dirt Bike.

Shop Oil Filters for a 2015 Yamaha YZ250 Dirt Bike.

Shop Oil Drain Pans for a 2015 Yamaha YZ250 Dirt Bike.

Shop Tools for a 2015 Yamaha YZ250 Dirt Bike.

Shop Oil Fillers and Drain Plugs for a 2015 Yamaha YZ250 Dirt Bike.

Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.