How to Change the Oil in a 1985 Honda CR250

Shop parts for a 1985 Honda CR250 Dirt Bike.

Regular oil changes are crucial for the longevity and top-notch performance of your 1985 Honda CR250. This guide, proprietary to MotoSport.com, covers every step, tool, and specific call-out for changing the transmission oil (gear oil) in your vintage two-stroke.

Tools and Supplies Needed

  • Drain pan – To catch old oil
  • Rubber gloves – To protect your hands
  • 17mm socket/wrench – For drain bolt removal
  • 10mm socket/wrench – May be needed for side covers or check bolt
  • Rag – For cleaning spills and parts
  • Transmission Oil: 10W-40 recommended, Maxima MTL is a popular choice
  • Ratio Rite measuring cup – For precise measurement
  • Funnel – To prevent spills when refilling

Recommended Oil Quantity

  • If you own a 1985–1989 Honda CR250, you will generally use 0.6 liters (600cc) of oil after a change. For 1989 and newer, the spec goes to 0.7 liters (700cc), so always double-check your owner's/service manual if your bike is in transition years.
    Call-out: For your 1985 model, use 600cc (refer to your service manual for exact capacity)

Step-by-Step Oil Change Instructions

  1. Warm Up the Engine
    • Start your CR250 and let it run for a few minutes. This warms the oil, allowing it to drain more thoroughly and carry out more contaminants.
  2. Position the Bike
    • Put your bike on a level stand. This ensures accurate draining and proper refilling.
  3. Gather Tools & Supplies
    • Place an oil drain pan directly beneath the bike’s transmission oil drain bolt.
  4. Remove the Oil Filler Cap
    • Locate and remove the oil filler cap on the right crankcase cover. This allows air to enter and oil to drain out smoothly.
  5. Remove the Drain Bolt
    • Using your 17mm socket, carefully loosen and remove the drain bolt at the bottom of the engine. Allow the oil to drain completely. Be patient—tipping the bike gently side to side helps remove more old oil, as described by expert mechanics.
      Call-out for CR250: The drain bolt is conveniently located, so you won’t be making a mess if you’ve warmed the bike up first.
  6. Inspect and Clean the Drain Bolt
    • Check for metal shavings or contamination on the magnet (if equipped). Wipe clean with a rag.
  7. Reinstall the Drain Bolt
    • Thread the bolt back in by hand, then tighten snugly with your wrench. Do NOT overtighten, as stripping the aluminum crankcase is a common mistake—torque spec is 8–12 Nm (6–9 ft-lbs).
  8. Measure and Add Oil
    • Use your measuring cup to fill exactly 600cc of 10W-40 transmission oil. Pour slowly through a funnel into the oil filler port.
  9. Replace Filler Cap and Check Level
    • Reinstall the filler cap securely. For a level check, locate the oil check bolt. With the bike upright, remove this check bolt: if oil flows out, the level is correct. If not, slowly add oil until it does.
      Tip: Start the bike and run for a minute, then repeat the level check as oil may need to settle through the cases.
  10. Clean Up and Inspect
    • Wipe away any spilled oil, check for leaks at the drain and filler, and properly dispose of the used oil.

Specific Call-Outs for the 1985 Honda CR250

  • The 1985 CR250 uses a transmission/gear oil system (not engine oil, as it's a two-stroke). Always use high-quality 2-stroke transmission oil for best clutch and gear life.
  • Do NOT overfill—the correct level is crucial for smooth shifting and clutch performance. Too much oil can cause drag and clutch issues.
  • Check for leaks around the drain bolt and filler after the change, especially if your bike has older gaskets or has seen heavy use.
  • Always use the torque spec for bolts to avoid costly damage to a vintage crankcase.
  • Change the oil every 3 races or 7.5 hours of riding, as recommended by factory service manuals.

Safety Note

  • Used oil can be a skin irritant and environmental hazard—dispose of it at a certified recycling center.

Changing the oil on your 1985 Honda CR250 is straightforward when you follow these steps and heed model-specific advice. Keeping up with regular oil changes ensures your legendary Honda runs strong for many rides to come.

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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.