How to Change the Oil in a 2018 Yamaha WR450F

Changing the oil on your 2018 Yamaha WR450F is an essential part of regular maintenance, ensuring your dirt bike continues to run at peak performance and prolonging its engine life. This guide is tailored specifically for the 2018 WR450F and is proprietary content for MotoSport.com.

Tools and Supplies Needed

  • 10mm and 12mm socket or box wrenches
  • 8mm socket or wrench (for skid plate or belly pan, if installed)
  • Oil catch pan
  • New oil filter (recommended: OEM or high-quality aftermarket)
  • Replacement oil drain bolt washer (crush washer)
  • 1 liter (approx. 1.06 US quarts) of 10W-40 4-stroke engine oil
  • Funnel
  • Shop towels or lint-free rags
  • Torque wrench (for precise bolt tightening, recommended)
  • Gloves (optional, for hot oil protection and cleanliness)

Step-by-Step Instructions

  1. Warm Up the Engine
    Start your WR450F and let it idle for a few minutes. This heats the oil and helps suspend contaminants, making it drain faster and more completely.
    Note: The WR450F is equipped with an engine auto-stop system that will shut off the engine after about seven minutes of idling, so you don't need to warm it up for long.
    Make sure the bike is upright and on level ground during this process.
  2. Remove the Skid Plate (Belly Pan, if equipped)
    Using an 8mm wrench or socket, remove the three bolts securing the skid plate and set it aside. This allows clear access to the oil drain bolt.
    On the 2018 model, this is a simple process—watch for washers and hardware that may drop.
  3. Unscrew the Oil Filler Cap
    This cap is located on the right side of the bike. Removing it allows oil to drain faster and more smoothly.
    Set the cap somewhere clean.
  4. Drain the Engine Oil
    Place your oil catch pan beneath the drain bolt (just behind and below the right crankcase area).
    Use a 12mm wrench to carefully remove the drain bolt and crush washer.
    Allow the oil to drain fully.
    Model-Specific Call-out: The 2018 WR450F’s oil drain bolt is easily accessible, and the oil drains rapidly due to the low capacity. Ensure the bike is upright–not on the sidestand–to maximize drainage.
    Let the oil drip until it slows to a very thin stream for the most complete change.
  5. Replace the Drain Bolt Washer
    Always install a new crush washer on the drain bolt to prevent oil leaks. Old washers can allow leaks and eventually damage the bolt seat.
    Reinstall the drain bolt and tighten by hand, then torque to spec (usually around 17 Nm, double-check your manual if possible).
    This is an often-skipped but vital step for all WR450F owners.
  6. Remove and Replace the Oil Filter
    Locate the oil filter cover just ahead of the shift lever.
    Remove the three 10mm bolts holding the cover (torque to approx. 10 Nm on reinstallation).
    Carefully remove the oil filter and allow excess oil to drain out.
    Wipe out the filter cavity and inspect or replace the cover O-ring if necessary.
    Insert the new oil filter; the hole faces the engine. Installing the filter backward can cause catastrophic engine damage.
    Reinstall the oil filter cover, tightening fasteners evenly to the correct torque.
  7. Refill the Engine with New Oil
    Use a funnel and pour in the recommended amount of 10W-40 motorcycle oil (typically 1 liter with filter change).
    Replace the oil filler cap.
  8. Check the Oil Level
    Start the engine and idle for a minute. Shut off and wait a minute.
    With the bike upright and on a level surface, remove the filler cap and inspect the oil level (using the dipstick or sight glass as appropriate for the 2018 model). Add oil if needed, but do not overfill.
    Inspect around the drain bolt and filter cover for leaks.
  9. Reinstall the Skid Plate
    Reinstall the skid plate using the original hardware, ensuring all bolts are snug.
    Clean up spilled oil and dispose of used oil/filter responsibly.

Model-Specific Tips and Warnings

  • 2018 Yamaha WR450F uses approximately 1 liter of oil with a filter change, but always check your owner’s manual for exact amounts.
  • The WR450F oil filter must be installed with the hole facing inwards toward the engine—incorrect installation can cause severe engine damage.
  • Torque specs matter: Over- or under-tightening drain or filter bolts can strip threads or cause leaks.
  • Replace the crush washer every oil change to avoid seepage–this is a common issue on these models.
  • The engine’s auto-stop feature prevents excessive idling; don’t let the bike idle excessively to warm it up, a few minutes is sufficient.
  • Avoid overtightening the oil filter cover bolts–the aluminum threads can easily crack if overtightened.

Conclusion

Maintaining your WR450F’s oil will ensure strong performance on every ride. Following these steps makes the job safe, effective, and straightforward. For all your OEM and aftermarket oil change products, trust MotoSport.com for the best performance parts and supplies.

Related Shopping Categories

Shop Motor Oil for a 2018 Yamaha WR450F Dirt Bike.

Shop Oil Filters for a 2018 Yamaha WR450F Dirt Bike.

Shop Oil Drain Pans for a 2018 Yamaha WR450F Dirt Bike.

Shop Tools for a 2018 Yamaha WR450F Dirt Bike.

Shop Oil Fillers and Drain Plugs for a 2018 Yamaha WR450F 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.