How to Change the Coolant in a 1987 Honda CR80
Shop parts for a 1987 Honda CR80 Dirt Bike.
Changing the coolant on your 1987 Honda CR80 is a straightforward task that ensures optimal engine cooling performance, extends component life, and helps prevent corrosion and overheating. Here's a proprietary MotoSport guide tailored to your vintage CR80.
Why Coolant Change Matters for Your CR80
The CR80 two-stroke engine relies on fresh coolant to maintain correct operating temperatures and avoid internal damage. Old coolant can corrode passages and reduce the effectiveness of your radiator, which is especially important for the high-revving, race-proven CR80 engine design.
What You'll Need
- Fresh coolant (ethylene glycol premix recommended for Honda dirt bikes)
- Distilled water (for system flush, optional but beneficial)
- Drain pan
- 10mm wrench or socket (common for radiator drain bolt)
- Screwdriver (for hose clamps if needed)
- Clean rags
- Funnel
- Crush washer (replace if worn or damaged to prevent leaks)
- Gloves and safety glasses
Step-by-Step Coolant Change Instructions
- Let the engine cool. Never open the radiator cap on a hot engine. Wait until the bike is cool to the touch to avoid burns.
- Remove the radiator cap. Release any remaining pressure slowly by turning the cap counterclockwise. Removing the cap allows the coolant to drain freely.
- Locate the radiator drain bolt. Most CR80s position this at the bottom of the left-side radiator. Place your drain pan beneath it.
- Remove the drain bolt. Use a 10mm wrench or socket to carefully remove the drain bolt and washer. Allow all old coolant to drain into the pan. Inspect the washer; replace if necessary to avoid leaks on reassembly.
- Flush the system (optional but recommended for neglected bikes). Temporarily reinstall the drain bolt, fill the radiator with distilled water, and run the engine for 2-3 minutes. Let the engine cool, then repeat the drainage process to flush out any lingering debris or old coolant.
- Reinstall the drain bolt and washer. Tighten firmly – do not overtighten. Ensure the crush washer is in good condition.
- Add new coolant. Using your funnel, slowly fill the radiator to just below the filler neck with premixed coolant. Stop if air bubbles surface and wait for them to clear before topping off. Some CR80 models include a small bleed bolt on the cylinder head or thermostat housing – loosen this bolt briefly while filling to let any trapped air escape (consult your service manual if present on your model).
- Bleed air from the system. With the radiator cap off, start the engine and let it idle for a few minutes. Gently rock the bike side to side or blip the throttle to move trapped air upward. Bubbles may surface. Top off coolant as the level drops.
- Check coolant level and radiator cap. Once idling smooth and no more bubbles rise, replace the radiator cap. Inspect the reserve tank (if equipped) and fill to the correct line.
- Thoroughly clean up and safely dispose of old coolant. Ethylene glycol is hazardous – never pour it down drains or onto the ground.
Model-Specific Notes for the 1987 Honda CR80
- The 1987 CR80 has a compact, high-revving two-stroke engine that runs hotter than modern four-strokes. Overheating from coolant neglect can cause rapid piston wear or seizure.
- This model year uses a single radiator – pay attention to the radiator's age, as fins or seams can corrode with time. Inspect for leaks or physical damage at every coolant change.
- The factory-recommended mixture is typically 50/50 coolant and distilled water. Avoid using tap water, as minerals can cause deposits.
- Any sign of persistent bubbles after multiple bleeds may point to a failing head gasket – more likely on older engines. Monitor the condition of the coolant for oil contamination.
Finishing Touches & Maintenance Tips
- Check the coolant level again after your next ride as air can work its way out during initial heat cycles. Top up as needed.
- Replace coolant every two years or as directed by your maintenance schedule for best protection & performance.
- If racing or riding in high-temperature environments, inspect radiator guards and clean out debris to ensure proper airflow.
Related Shopping Categories
Shop Radiators for a 1987 Honda CR80 Dirt Bike.
Shop Coolant for a 1987 Honda CR80 Dirt Bike.
Shop Temperature Sensors for a 1987 Honda CR80 Dirt Bike.
Shop Tools for a 1987 Honda CR80 Dirt Bike.
Shop Radiator Hoses for a 1987 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.