How to Change the Coolant in a 1989 Honda CR250: Step-By-Step Guide

Shop parts for a 1989 Honda CR250 Dirt Bike.

Your 1989 Honda CR250 is a race-bred machine designed for serious performance, and routine coolant changes are crucial for protecting the high-revving engine from dangerous overheating. Coolant degrades over time and, especially in vintage models with aluminum radiators like your CR250, fresh coolant helps prevent scaling, corrosion, and internal damage. This model requires diligence, as an incorrect coolant or improper flush can have long-lasting impact. Let&s walk through the process to keep your machine running cool.

What You Need

  • High quality ethylene glycol based coolant (safe for use with aluminum radiators)
  • Drain pan
  • Socket wrench with 10mm socket
  • New water pump crush washer (recommended)
  • Funnel
  • Clean water (for flushing, optional)
  • Gloves & shop rags

Step 1: Preparation

  • Make sure the engine is completely cool.
  • Place the bike upright on a level surface. Remove any body panels, the seat, and the fuel tank for easier access to the radiator cap and hoses if necessary.

Step 2: Draining the Old Coolant

  • Locate the radiator cap on the left side of the bike and remove it to relieve any leftover pressure in the system.
  • Find the coolant drain bolt–typically the lowest water pump bolt on the right engine cover. Place a drain pan under this bolt.
  • Loosen and remove the drain bolt. Allow the coolant to drain completely.
  • For a thorough flush, you can refill the system with distilled water, reattach the bolt, run the engine briefly, and repeat the drain process until clear fluid exits.

Step 3: Inspect and Replace Components

  • Inspect the removed drain bolt's crush washer. Replace it if it shows any signs of wear or deformation.
  • Check the radiator cap's rubber seal for cracks or damage.

Step 4: Refilling with New Coolant

  • Reinstall the drain bolt and torque it snug, but do not overtighten (refer to your service manual, but 7–9 lb-ft is typical for small bolts).
  • Using a funnel, slowly fill the radiator with your ethylene glycol based coolant until the fluid is visible at the base of the filler neck.
  • Rock the bike gently to help release any trapped air bubbles. You may need to "burp" the system by squeezing the radiator hoses.

Step 5: Bleeding and Verifying

  • Leave the radiator cap off and start the engine. Let it idle for a couple minutes.
  • Keep an eye on how the coolant level drops as trapped air escapes; add coolant as needed.
  • Once the coolant level stabilizes, shut off the engine and top off again if necessary. Reinstall the radiator cap securely.

Step 6: Final Check

  • Inspect around the drain bolt and hoses for leaks.
  • Test ride the bike until fully warm. After cooling, recheck the coolant level and top off if necessary.

Special Notes for 1989 Honda CR250 Owners

  • This year's CR250 uses a magnesium case for reduced weight, which is susceptible to corrosion–never use straight water for extended periods.
  • Always ensure your coolant is silicate-free and rated for aluminum cooling systems to prevent internal pitting of the radiator and water pump.
  • If racing or riding in extremely hot conditions, consider checking the coolant after every hard ride for peace of mind.

With periodic coolant changes, your 1989 CR250 will maintain peak power output and keep its legendary reliability. Always dispose of old coolant legally and protect pets–ethylene glycol is toxic if ingested.

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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.