How to Change the Oil in a 2004 Honda CR125: A MotoSport.com Guide

Shop parts for a 2004 Honda CR125 Dirt Bike.

Changing the oil in your 2004 Honda CR125 is vital maintenance that keeps your dirt bike’s transmission in top shape, ensuring smooth shifts and extended component life. This guide provides detailed instructions, including required tools, step-by-step procedures, and specific call-outs for your model year.

Tools & Supplies Needed

  • 10mm, 17mm socket or wrench (for filler and drain bolts)
  • Oil drain pan
  • Rags or shop towels
  • Replacement sealing washer/crush washer (highly recommended every change)
  • New transmission oil (Pro Honda HP Transmission Oil or equivalent 2-stroke transmission oil, 0.60 US qt / 0.57 L)
  • Torque wrench
  • Measuring cup for oil
  • Small funnel (optional for cleaner fill-up)
  • Nitrile gloves (recommended)

Step-by-Step Oil Change Procedure

  • 1. Warm Up the Engine
    Run your CR125 for about three minutes to warm up the oil. Warm oil drains more easily and removes more contaminants.
    Pro tip: Don’t rev the engine hard—just enough to circulate the oil fully.
    Specific to 2004 CR125: The procedures remain consistent with CR125s across early 2000s model years.
  • 2. Position the Bike
    Place your CR125 upright (use a triangle stand or similar) on a level surface. This helps ensure the oil drains completely and that you fill to the correct level.
  • 3. Remove the Filler Cap
    Locate the oil filler cap on the right crankcase cover and remove it. This step lets air in and speeds up oil drainage.
  • 4. Drain the Old Oil
    • Place the oil drain pan beneath the engine.
    • Locate the oil drain bolt (17mm) on the bottom of the crankcase.
    • Remove the drain bolt carefully. Have rags handy to catch any drips.
    • Allow oil to drain until the flow reduces to a slow drip.
    • Inspect the oil—grayish tint indicates normal clutch wear, but metallic shavings may signal other issues.
  • 5. Replace the Sealing Washer & Reinstall Drain Bolt
    • Inspect the sealing (crush) washer on the drain bolt. Replace it if it’s deformed or worn—doing so prevents leaks.
    • Reinstall the drain bolt and torque to 21 lbf·ft (29 N·m).
  • 6. Add Fresh Oil
    • Use a funnel to pour in 0.60 US quarts (0.57 liters) of the recommended oil (Pro Honda HP2 2-stroke oil or equivalent).
    • Do not overfill—accurate measurement is key for performance and longevity.
  • 7. Check the Oil Level
    • With the bike upright and level, insert (but don’t screw in) the dipstick/oil check bolt, then remove to check oil level.
    • Add small amounts if necessary, but never exceed the indicator line.
    • Secure the oil filler cap and oil check bolt; torque to 7 lbf·ft (10 N·m) if tool is available.
  • 8. Clean Up and Dispose of Oil Properly
    • Wipe any spilled oil from engine surfaces.
    • Dispose of the used oil at a certified recycling center—do not pour it down drains or on the ground.

Special Call-outs & Tips for 2004 Honda CR125 Owners

  • Do not confuse the oil fill for the transmission oil (right side, larger cap) with the coolant or 2-stroke mix.
  • Like all CR125s from the late 1990s through mid-2000s, there is no oil filter to change—just replace oil as shown.
  • Use only 2-stroke specific gear/transmission oil for best clutch and gearbox performance.
  • Changing the oil every 5–10 hours of riding (or sooner if racing in mud/sand) will help reduce wear and costly repairs.

Conclusion

This oil change is a simple but significant service for your 2004 Honda CR125. Following these steps and recommendations will help keep your bike running strong on the track or trail. For all genuine parts, oils, and performance upgrades, shop MotoSport.com

Related Shopping Categories

Shop Motor Oil for a 2004 Honda CR125 Dirt Bike.

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Shop Oil Drain Pans for a 2004 Honda CR125 Dirt Bike.

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Shop Oil Fillers and Drain Plugs for a 2004 Honda CR125 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.