How to Change the Oil in a 2019 Honda CRF450RX

Shop parts for a 2019 Honda CRF450RX Dirt Bike.

Keeping your 2019 Honda CRF450RX running at its best means regular oil changes. Honda recommends changing the oil after every six races or after 15 hours of use. The oil change process is straightforward, but paying attention to specific steps and details for this model will help ensure optimal performance and engine longevity.

Tools and Supplies You’ll Need

  • 8mm and 10mm sockets and ratchet
  • 10mm Allen (hex) wrench
  • Torque wrench
  • Honda oil filter
  • Honda 20W-50 motor oil (check your owner’s manual for temperature-specific oil weights)
  • New crush washer
  • Replacement O-ring/gasket for drain bolt
  • Oil drain pan
  • Shop rags
  • Funnel (optional but recommended)

Before You Start

  • Warm up your engine for 2-3 minutes. Warm oil flows faster and helps remove more contaminants.
  • Work on a stable surface with your bike upright and secure.

Step-by-Step Oil Change Guide

  1. Remove the skid plate/engine guard:
    • Use a 10mm socket to remove the three bolts (left, right, and bottom) that hold the skid plate. Set it aside.
  2. Remove the oil filler cap:
    • Take off the cap on the top of the engine to allow air in and help the old oil drain thoroughly.
  3. Drain the oil:
    • Place your oil pan beneath the bottom of the engine.
    • With a 10mm Allen wrench, remove the drain plug from the lower rear of the crankcase. (Note: The factory bolt is large and can make oil removal messy; have plenty of rags handy and expect a large flow initially.)
    • Remove the old crush washer and O-ring (if applicable). Discard them.
  4. Let the oil drain completely:
    • This may take several minutes. Lightly rocking the bike can help remove trapped oil.
  5. Remove and replace the oil filter:
    • Remove the left side engine guard if needed (8mm or 10mm socket).
    • Take out the two cover bolts (usually 8mm or 10mm) and gently remove the cover.
    • Pull out the old filter, noting its direction for reinstallation.
    • Wipe the filter cavity with a clean rag.
    • Lubricate the new filter’s gasket with fresh oil, then install it.
    • Replace the O-ring for the filter cover if it appears worn or damaged.
    • Reinstall the cover and torque the bolts to 9 foot-pounds.
  6. Reinstall the drain plug:
    • Add a new crush washer and O-ring to the cleaned plug. Tighten with the 10mm Allen wrench until snug (do not overtighten; refer to your service manual for proper torque).
  7. Add new oil:
    • Insert a funnel into the filler hole.
    • Pour in Honda 20W-50 engine oil, starting with the manufacturer’s recommended capacity (usually about 1 quart, but confirm via the user manual).
    • Check the oil level through the sight glass; add oil if needed, but do not exceed the maximum mark.
  8. Reinstall the oil filler cap and engine guard/skid plate:
    • Tighten all bolts to their specified torque values. Double check that the oil drain bolt and oil filter cover are properly secured.
  9. Start your engine and check for leaks:
    • Let the engine idle for 1-2 minutes, then shut it off and inspect for oil leaks at the drain bolt and filter cover.
    • Re-check the oil level once the bike has sat for a few minutes and top off if necessary.

Important 2019 Honda CRF450RX Call-Outs

  • Large Drain Plug Caution: The 2019 CRF450RX uses a large drain bolt which can result in a big, fast pour of oil. Be prepared for this by using a wide oil catch pan and protective rags to manage spills.
  • Oil Level Window: Instead of a dipstick, this bike uses a sight glass on the crankcase to check the oil level–ensure you are on level ground when checking.
  • Oil Change Interval: Honda recommends oil changes every 15 hours or after six races–a more frequent interval than some bikes; track your ride time closely.
  • Gasket and O-ring Inspection: Always inspect and replace the drain bolt O-ring and oil filter cover O-ring if they show any wear or damage to prevent leaks.
  • Correct Oil Type: Use 20W-50 or as specified for the temperatures you ride in. Avoid car oil; use only motorcycle-specific, wet-clutch safe oil.
  • Dispose of Used Oil Properly: Take your used oil and filter to a local recycling center or auto parts retailer.

Changing the oil is a simple job that can greatly extend the life of your 2019 Honda CRF450RX. Always double check your work and refer to the owner’s manual or a certified technician if you encounter any unusual issues. For genuine parts, oil, and expert gear, trust MotoSport.com to keep your Honda running at its best.

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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.