How to change the oil in a 2021 Honda CRF450R Dirt Bike

How to Change the Oil in a 2021 Honda CRF450R: Complete Step-by-Step Guide

Shop parts for a 2021 Honda CRF450R Dirt Bike.

Regular oil changes are critical for ensuring the longevity and peak performance of your 2021 Honda CRF450R. Honda recommends oil and filter changes every six races or 15 hours of use, but aggressive riding may demand even more frequent service. This guide is proprietary to MotoSport.com and will walk you through the process, including the specific tools required and vital notes unique to this model.

Tools and Parts Needed

• 8mm socket
• 10mm socket (for drain bolt and filter cover bolts)
• Ratchet
• Torque wrench (for correct reinstallation torque)
• Honda oil filter (OEM recommended for best fit)
• Honda 20W-50 motor oil (or as specified in the manual)
• New crush washer for the drain bolt
• O-ring for the oil filter cover (replace if damaged)
• Engine oil drain pan
• Funnel
• Clean rags
• Latex gloves and safety glasses (recommended)

Model-Specific Callouts for 2021 CRF450R

• Torque Specifications:– The oil filter cover bolts should be torqued to 9 ft-lbs.
• Oil Filler Cap:– Located on the left side—removing this prior to draining oil will improve flow.
• Sight Glass:– The oil level is checked via a sight glass below the oil filter cover.
• Drain Bolt Location:– The 10mm oil drain bolt is under the lower rear of the crankcase.

Steps to Change the Oil in a 2021 Honda CRF450R

• Warm Up the Engine
  • Start the motorcycle and let it idle for about a minute. Warming the oil helps suspend contaminants and enables a thorough drain.
• Remove Engine Guards and Skid Plate
  • Using the 8mm and/or 10mm socket, take off the left engine guard to access the oil filter cover. If your bike is equipped with a skid plate, remove it to easily access the drain bolt.
• Open Oil Filler Cap
  • Remove the oil filler cap to allow the crankcase to vent, ensuring oil drains quickly and fully.
• Drain the Engine Oil
  • Place the oil drain pan under the drain bolt at the lower rear of the crankcase.
  • Remove the 10mm drain bolt and its crush washer. Be cautious as the oil may be hot.
  • Allow all oil to drain—this may take a few minutes.
• Replace the Crush Washer and Reinstall the Drain Bolt
  • Install a new crush washer on the drain bolt and reinstall it, tightening with a torque wrench to the manufacturer’s specification if provided. Do not over-tighten, as this can damage the case.
• Replace the Oil Filter
  • Remove the oil filter cover (secured by two 8mm or 10mm bolts).
  • Take out the old oil filter and any remaining O-ring. Replace the O-ring if cracked or worn.
  • Install the new oil filter (open side facing out, spring side in if applicable).
  • Reinstall the oil filter cover and torque its bolts evenly to 9 foot-pounds.
• Reinstall Guards and Skid Plate
  • Reinstall the left side engine guard and any skid plate you removed.
• Add New Engine Oil
  • Using a funnel, pour Honda 20W-50 engine oil (or the recommended type/viscosity) slowly into the filler opening.
  • Check your owner’s manual for the exact oil capacity. Do not overfill.
• Check Oil Level
  • With the bike on a level surface, check the oil level through the sight glass just below the oil filter cover. Top off if necessary.
  • Replace the oil filler cap once the level is correct.
• Start Engine and Recheck for Leaks
  • Start the engine and let it idle for a minute. Shut it off, wait a few minutes, and recheck the oil level, topping off as needed.
  • Inspect for leaks around the filter cover and drain bolt.

Tips & Best Practices

• Always use the recommended oil and OEM filters for the best engine protection and fit.
• Dispose of used oil and filters responsibly at your local auto parts store or recycling center.
• Tighten all bolts to specifications to avoid leaks and damage.
• Record your oil changes and hours of use to stay on schedule.
• If you race or ride aggressively, consider changing oil even more frequently than Honda suggests.

Key Differences and Reminders for the 2021 CRF450R

• The 2021 model has a uniquely designed left-side engine guard and sight glass, making oil level checks straightforward but requiring the guard be removed for filter access.
• Thread sizes and torque specs have changed from previous years; always double-check with your owner's manual.
• The CRF450R’s high-revving engine and small oil capacity demand frequent, careful oil maintenance.

Following these steps will ensure your 2021 Honda CRF450R runs strong and lasts longer. For all your OEM parts and supplies, trust MotoSport.com for expert support and fast shipping on everything you need.

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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.