How to Change the Coolant in a 1994 Honda CR250

Shop parts for a 1994 Honda CR250 Dirt Bike.

Keeping your 1994 Honda CR250's cooling system in top shape is essential for engine performance and reliability, especially on the track or trail. Coolant not only manages engine heat but also protects internal passages from corrosion and deposit buildup. Here is a step-by-step, MotoSport-exclusive guide to confidently change your CR250's coolant with tips that matter most for this iconic 2-stroke.

What You Need

  • Silicate-free, ethylene glycol-based motorcycle coolant (avoid automotive coolants that may harm aluminum radiators)
  • 5mm Allen key (for radiator shroud plastics)
  • 10mm socket or wrench (for water pump drain bolt)
  • Phillips screwdriver (radiator cap retainer)
  • Funnel and a drain pan
  • Replacement crush washer for the drain bolt
  • Clean rags
  • Gloves and safety glasses

Steps to Change the Coolant

  • Ensure the engine is completely cool. Never open the radiator cap on a hot engine due to risk of pressurized steam and hot coolant.
  • Remove the seat and radiator shrouds to access the radiator cap and water pump area. Use the 5mm Allen key for shrouds.
  • Place your drain pan beneath the engine's right side, under the water pump.
  • Remove (do not lose) the radiator cap. If there's a Phillips-head retainer screw, remove it first. This releases pressure and allows fluid to drain freely.
  • Locate the coolant drain boltthis is the lowest bolt on the water pump cover, typically a 10mm. Remove the bolt and washer; coolant will start draining. Inspect and replace the crush washer with a new one to ensure a tight seal.
  • Gently tilt the bike side to side (rock it from the footpegs) to help drain any trapped coolant from the crankcase and hoses.
  • After draining stops, reinstall the drain bolt with your fresh crush washer. DO NOT overtighten; snug it just past finger-tight with your 10mm wrench or socket.
  • Slowly pour fresh coolant into the radiator using your funnel until it sits just below the filler neck. Leave a small air gap for expansion.
  • Reinstall the radiator cap and any retainer hardware. Make sure the cap seats securely.
  • Start the bike and let it idle for 2-3 minutes with the radiator cap on to circulate coolant and remove air pockets. Shut off the bike, allow it to cool, then check and top off coolant as necessary.
  • Reinstall plastics and seat after confirming there are no leaks.

CR250-Specific Tips – 1994 Model Notes

  • The 1994 CR250 uses a relatively simple, open two-stroke cooling system with no external reservoir. Always fill from the radiator neck directly.
  • Inspect your radiator hoses and clamps: These older lines may become brittle. Consider a hose kit replacement during this service if you see swelling, cracks, or leaks.
  • Use only ethylene glycol-based, silicate-free coolant; this protects the CR250's aluminum radiator from internal corrosion.
  • Replacement parts: The radiator drain bolt crush washer (Honda part 90463-ML7-000) should always be swapped at each service to prevent leaks.
  • Overfilling can lead to coolant overflow when riding hard, especially as the 1994 CR250 does not have an overflow tank like newer modelsfill just to the bottom of the filler neck.

Final Check

  • Start the bike, let it idle, and check the radiator and water pump area for leaks.
  • If you notice foaming, excessive bubbles, or repeated overflow, recheck for trapped air or drain and fill again.

Changing coolant is a simple way to extend your 1994 Honda CR250's service life and deliver consistent power when you twist the throttle. Stay ahead of overheating and protect your ridehappy wrenching.

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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.