How to Change the Oil in a 2019 Yamaha YZ250: Step-by-Step Guide

Shop parts for a 2019 Yamaha YZ250 Dirt Bike.

This proprietary MotoSport.com blog provides a comprehensive, model-specific walkthrough for changing the oil in your 2019 Yamaha YZ250. Proper maintenance is crucial to ensure smooth shifting, clutch performance, and long engine life, so follow these robust steps designed specifically for Yamaha’s legendary two-stroke.

Tools and Supplies Needed

  • Socket wrench set (especially a 12mm socket for the drain bolt)
  • Drain pan or container
  • Fresh transmission oil (generally 10W-40 or manufacturer-recommended type)
  • Oil funnel (optional, but minimizes mess)
  • Rags or shop towels
  • Replacement copper washer/gasket (recommended for the drain bolt)
  • Rubber gloves (optional, for cleanliness)

Specific Call-Outs for the 2019 Yamaha YZ250

  • No oil filter: Unlike modern four-stroke bikes or YZ250F models, the 2019 Yamaha YZ250 is a two-stroke engine and uses a separate transmission oil, not shared engine oil. There is no oil filter to replace on this transmission system.
  • Oil capacity: The total transmission oil capacity is approximately 0.85 US quarts (about 0.8 liters). Do not overfill.
  • Engine warm-up: Warming up the engine helps suspend particles in the oil and allows a more thorough drain.

Steps to Change Transmission Oil in Your 2019 YZ250

  1. Warm Up the Engine
    Start your YZ250 and allow it to idle for 2-3 minutes. This brings the oil up to temperature, helps collect debris, and makes draining easier and more effective. Never drain oil from a cold engine.
  2. Turn Off the Engine and Prepare
    Shut the bike off and position it securely—ideally on a stand. Place the drain pan directly under the transmission drain plug (look under the engine, typically on the left side).
  3. Remove the Drain Bolt
    Use a 12mm socket wrench to carefully remove the drain plug. Let all the oil drain into your container. Be patient and allow several minutes for all oil to exit. Inspect the old oil for excessive debris or unusual color, which could indicate clutch or gear issues.
  4. Remove the Oil Filler Cap
    While the oil finishes draining, remove the transmission oil filler cap (usually on the clutch side, top of the engine case). This helps vent the chamber and allows thorough drainage.
  5. Replace the Drain Bolt
    Inspect the drain bolt and the copper washer/gasket. Replace the washer if crushed or worn to prevent leaks. Hand-tighten the bolt, then torque to manufacturer specs (typically around 14 ft-lbs; consult your Yamaha service manual for confirmation).
  6. Add Fresh Transmission Oil
    Use a funnel to pour new transmission oil into the filler opening. Pour slowly and check the level frequently to avoid overfilling. For the 2019 YZ250, use approximately 0.85 US quarts (0.8 liters) of oil.
  7. Reinstall the Filler Cap
    Once oil reaches the correct level (there is typically a sight glass or dipstick – check your owner’s manual for exact method), securely reinstall the filler cap.
  8. Check for Leaks and Final Steps
    Start your engine and run it briefly, then turn it off and inspect for leaks around the drain bolt and filler area. Wipe up any spills and re-check the oil level, topping up if necessary.
  9. Proper Oil Disposal
    Used transmission oil should be recycled responsibly. Never pour it down the drain or onto the ground. Most motorcycle shops and auto parts stores accept used oil for recycling.

Additional Tips for YZ250 Owners

  • Oil change interval: Depending on your riding conditions, it’s recommended to change the transmission oil every 5-10 hours of riding or after every race for maximum gearbox protection.
  • No engine oil: As a two-stroke, the YZ250’s crankshaft and cylinder are lubricated by the pre-mixed fuel, not the transmission oil. Changing the transmission oil affects only clutch and gear operation.
  • Check for water or debris: Milky oil may indicate water intrusion (bad seal or gasket). Metallic flakes can signal internal component wear.

Conclusion

Changing the transmission oil on a 2019 Yamaha YZ250 is straightforward, requires minimal tools, and is an essential aspect of regular maintenance. By using the correct oil volume and performing this routine service, you’ll protect your clutch and gearbox while ensuring optimal shifting and longer component life. Visit MotoSport.com for all your OEM Yamaha parts, premium oils, tools, and advice—keeping you ready to ride.

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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.