How to Change the Oil in a 1999 Honda CR125

Shop parts for a 1999 Honda CR125 Dirt Bike.

Keeping your 1999 Honda CR125 operating at its peak requires routine maintenance, with transmission oil changes topping the list. This step-by-step guide details the tools, procedures, and specific tips for the CR125, ensuring safe and reliable servicing. This how-to is proprietary content created exclusively for MotoSport.com.

Tools and Supplies Needed

  • 17mm socket or wrench (Drain bolt size specific to the CR125)
  • Socket wrench
  • Oil drain pan
  • Funnel
  • Clean rags or paper towels
  • New transmission oil (Honda recommends Pro Honda HP2 2-stroke oil or equivalent at 32:1, See Call-outs)
  • New sealing washer for the drain bolt
  • Measuring cup (to ensure the correct oil volume)
  • Torque wrench

1999 Honda CR125: Oil Change Procedure

  1. Warm Up the Engine
    • Start the bike and let it idle for 1-2 minutes. This allows the oil to heat up and become less viscous, so contaminants drain away more efficiently.
  2. Stabilize the Bike
    • Position the bike upright using a stand or have a helper keep it level. Place your drain pan beneath the engine's oil drain bolt.
  3. Remove the Filler Cap
    • Unscrew the filler cap on the right-side crankcase cover to allow air in, helping the oil drain smoothly.
  4. Drain the Oil
    • Use your 17mm socket to remove the oil drain bolt, located at the bottom of the right side of the engine.
    • Let the oil completely drain into the pan. Inspect the oil for any metal shavings or unusual discoloration which could indicate internal wear.
  5. Replace the Sealing Washer
    • Before reinstalling, fit a new sealing washer onto the drain bolt to prevent leaks.
  6. Reinstall and Torque the Drain Bolt
    • Screw in the drain bolt by hand to avoid cross-threading, then use a torque wrench to tighten it securely to 21 lbf·ft (29 N·m) .
  7. Add New Oil
    • Pour in 0.60 US qt (0.57 L) of the recommended transmission oil using your funnel. Do not overfill.
  8. Check Oil Level
    • Let the oil settle for a few minutes.
      Follow this procedure:
      • Wipe down the check bolt (located above the drain bolt).
      • Remove the check bolt; oil should just start to seep out. If not, add oil a little at a time, reinstall the check bolt, and check again.
      • Once level, reinstall and torque the check bolt to 7 lbf·ft (10 N·m) .
  9. Secure the Filler Cap
    • Screw the filler cap back on tightly.
  10. Dispose of Old Oil Responsibly
    • Transfer used oil into a suitable container and take it to a recycling facility. Never pour oil on the ground or into drains .

Model-Specific Call-Outs: 1999 Honda CR125

  • Transmission Oil Only: The CR125 is a 2-stroke; you are changing only the transmission/clutch oil, not engine oil. The engine is lubricated separately by the 2-stroke premix .
  • Oil Capacity: Do not exceed 0.60 US qt (0.57 L). Too much oil can cause seal leaks, while too little may lead to clutch damage .
  • Drain and Check Bolt Locations: The 1999 CR125 drain bolt uses a 17mm head, located at the bottom right of the case. The check bolt is directly above it—both are easy to strip if overtightened, so always use a torque wrench .
  • Oil Recommendations: Use only high-quality transmission/dirt bike gear oil. Honda's Pro HP2 or a dedicated 2-stroke gear oil at 32:1 is recommended .
  • Washer Replacement: The sealing washer should be replaced every oil change to prevent drips and maintain correct torque settings .

Quick Tips for First-Time CR125 Owners

  • Always run the engine briefly before starting—the oil will drain more completely when warm .
  • Inspect your oil after draining. Dark, burnt-smelling, or metal-laced oil suggests your clutch may need maintenance.
  • Change your transmission oil every 5-10 hours of riding for optimal clutch and transmission longevity.
  • Consult your owner's manual for other scheduled maintenance or torque settings if uncertain .

With these instructions and regular care, your 1999 Honda CR125 will deliver top performance on every ride. If you need Honda-approved oils, parts, or further tips, MotoSport.com is your trusted source.

Related Shopping Categories

Shop Motor Oil for a 1999 Honda CR125 Dirt Bike.

Shop Oil Filters for a 1999 Honda CR125 Dirt Bike.

Shop Oil Drain Pans for a 1999 Honda CR125 Dirt Bike.

Shop Tools for a 1999 Honda CR125 Dirt Bike.

Shop Oil Fillers and Drain Plugs for a 1999 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.