How to Change the Coolant in a 1985 Honda CR80
Shop parts for a 1985 Honda CR80 Dirt Bike.
Regularly changing the coolant in your 1985 Honda CR80 is essential for optimal performance and to prevent overheating or damage to the aluminum components. Here's a proprietary MotoSport guide specifically tailored to your MMY dirt bike – including important maintenance notes for the 1985 CR80's unique design.
What You'll Need
- Fresh ethylene glycol-based coolant that is aluminum-safe
- Distilled water for flushing (never tap water due to mineral deposits)
- Catch container for old coolant
- 8mm socket or wrench
- Funnel
- Replacement water pump crush washer (part 90463-ML7-000 is compatible with Honda water pumps)
- Shop rags
- Protective gloves & eyewear
Step-by-Step Coolant Change
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Make sure the engine is completely cold.
Open the radiator cap slowly to relieve any residual pressure. Never attempt to remove the radiator cap on a warm or hot engine. - Remove the skid plate if equipped for better access to the water pump. The CR80's water pump drain bolt is located on the lower right side.
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Place your catch container underneath the coolant drain bolt on the water pump.
Using your 8mm socket, remove the drain bolt and allow the coolant to flow out completely. Remove the radiator cap completely to help the coolant drain faster. -
Inspect and replace the water pump crush washer if worn.
This prevents leaks on reassembly—a must for older models like the '85 CR80. -
Flush the system with distilled water.
Pour distilled water carefully into the radiator, reinstall the drain bolt, then start and idle the engine for 1–2 minutes. Let the engine cool, remove the drain bolt, and drain the flush water. Repeat until the water runs clear. -
Reinstall the drain bolt (with new crush washer, if needed) and torque to spec.
Wipe any spilled coolant from the bike. -
Slowly refill the radiator with fresh ethylene glycol-based coolant.
Fill up to the filler neck but not above. Squeeze the lower radiator hose by hand several times to help purge air from the system. -
Reinstall the radiator cap securely.
Start the engine and let it idle for several minutes, watching the coolant level through the filler neck.
After the engine heats up, shut off and let it cool fully. Remove the cap and top off if necessary. -
Check the coolant level after your first ride.
Air bubbles may release during the initial operation, requiring a minor top-off.
Notes for 1985 Honda CR80 Owners
- Only use coolant labeled as safe for aluminum radiators; the CR80's lightweight cooling system is particularly susceptible to internal corrosion if the wrong type is used.
- The cooling system capacity for a typical CR80 is under 1 quart. Do not overfill—excess coolant will be vented out and can cause a mess.
- Old bikes like the 1985 CR80 may have brittle hoses or aging radiators. Inspect these for cracks or soft spots and replace them with high-quality parts for longevity.
- Always properly dispose of spent coolant — it is toxic for pets, people, and the environment.
Routine coolant changes keep your classic CR80 running cool all season long. With this MotoSport-specific guide, you can confidently maintain your ride – and enjoy every lap.
Related Shopping Categories
Shop Radiators for a 1985 Honda CR80 Dirt Bike.
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Shop Temperature Sensors for a 1985 Honda CR80 Dirt Bike.
Shop Tools for a 1985 Honda CR80 Dirt Bike.
Shop Radiator Hoses for a 1985 Honda CR80 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.