How to Change the Oil in a 2020 Yamaha WR450F

Shop parts for a 2020 Yamaha WR450F Dirt Bike.

Changing the oil in your 2020 Yamaha WR450F is essential maintenance that will keep your dirt bike running at top performance and extend its engine life. This detailed guide is proprietary to MotoSport.com and covers every tool you need, clear step-by-step instructions, and important model-specific tips to avoid issues specific to your WR450F.

Tools and Materials Needed

  • 8 mm and 12 mm socket or box-end wrenches (for skid plate, drain plug, and oil filter cover bolts)
  • Oil drain pan
  • Gloves (for protection from hot oil)
  • Clean rags or shop towels
  • Replacement oil filter
  • Replacement drain plug washer (copper preferred)
  • Funnel
  • Recommended engine oil: 10W-40 synthetic or as per Yamaha spec
  • Torque wrench (for filter cover bolts: set to 10 Nm)
  • Owner's manual (for checking oil quantity, specs, and verifying steps)

Model-Specific Call-Outs for the 2020 Yamaha WR450F

  • Skid Plate Removal: The WR450F features a straightforward skid plate mounting system with three bolts (some aftermarket plates use Allen bolts in front and an 8 mm bolt in the rear). You must remove the skid plate to access the drain plug easily.
  • Drain Plug and Washer: The drain plug is located toward the back right side of the engine. Always replace the copper washer to prevent future leaks.
  • Oil Filter Orientation: Install the new oil filter with the side that has the hole facing inward. Installing it backward can lead to catastrophic engine failure specific to this engine design.
  • Oil Capacity: With filter change, add approximately 1 liter (1.05 US qts) of oil. Confirm exact capacity in your owner's manual.
  • Auto-Stop System: Your model may have an auto-stop system—if so, it will cut the engine after 7 minutes of idling, a feature to prevent overheating while warming up the bike.

Step-by-Step Oil Change Instructions

  1. Warm Up the Engine: Start and run your WR450F for 3–5 minutes. This helps circulate the oil and suspend impurities, making it easier to drain out.
  2. Set Up Your Workspace: Put the bike upright on a flat, stable surface. Place the oil drain pan directly under the engine.
  3. Remove the Skid Plate:
    • Use 8 mm or Allen wrenches (depending on your skid plate) to remove the three retaining bolts.
    • Take the skid plate off and set aside with bolts organized.
  4. Remove the Oil Drain Plug:
    • With the engine still warm, use a 12 mm wrench to carefully loosen and remove the drain plug and copper washer from the right-rear underside of the engine.
    • Let oil drain completely (wait several minutes).
  5. Remove the Oil Filler Cap
    • This allows air in and speeds up oil drainage. Be careful—the engine and oil may be hot.
  6. Replace the Drain Plug and Washer:
    • Once all the oil has drained, wipe the area clean.
    • Install a fresh copper washer on the drain plug.
    • Hand-tighten the drain plug, then use a wrench to snug it (do not over-tighten).
  7. Remove the Old Oil Filter:
    • Using an 8 mm wrench, remove the oil filter cover (three bolts).
    • Take care not to lose the O-ring or the cover bolts.
    • Remove the old oil filter—note its orientation for correct installation of the new one.
    • Wipe the filter cavity clean with a rag.
  8. Install the New Oil Filter:
    • Install the new filter, aligning the hole inward. Incorrect installation can severely damage your engine.
    • Reinstall the filter cover and torque the bolts to 10 Nm.
  9. Check Oil Strainer (Optional but Recommended):
    • Yamaha recommends periodic removal and inspection of the oil strainer. Consult your manual for location and cleaning guidance.
  10. Add Fresh Oil:
    • With a funnel, pour in approximately 1 liter (or as per your manual) of 10W-40 oil.
    • Install and hand-tighten the oil filler cap.
  11. Start and Check Oil Level:
    • Start the engine for 1–2 minutes (do not rev hard), then shut it off and wait a minute.
    • With the bike upright, remove the dipstick, clean it, reinsert (do not screw in), and check the level.
    • Add or remove oil as needed until the level is correct.
  12. Reinstall the Skid Plate
    • Bolt it back in using the original hardware, ensuring it's secure.
  13. Dispose of Used Oil and Filter Responsibly: Take old oil and filter to a recycling center or auto parts store that accepts them.

Tips for WR450F Oil Changes

  • Change your oil every 5 rides or 1,000 kilometers (about 620 miles) for best engine longevity.
  • Always use a fresh, quality filter and proper grade oil to ensure correct lubrication.
  • Check for leaks at the drain plug and filter cover after every oil change.
  • Keep a maintenance log for your records (and resale value).

Regular oil changes are one of the most important maintenance tasks for your Yamaha WR450F. With the right tools, factory-recommended process, and these model-specific tips, you'll keep your bike running strong for years to come.
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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.