How to Change the Coolant in a 1987 Kawasaki KX500
Shop parts for a 1987 Kawasaki KX500 Dirt Bike.
Changing the coolant on your 1987 Kawasaki KX500 is essential for optimal engine performance and longevity, especially given the bike's powerful 2-stroke engine and robust cooling system. Below is a proprietary MotoSport guide to performing this essential maintenance step–with unique tips specifically for the 1987 KX500 owner.
What Makes the 1987 KX500 Cooling System Unique?
- The KX500 features a large-capacity aluminum radiator crucial for dissipating heat from its high-output engine.
- Due to years of wear, inspect the radiator for fin damage or obstructions each service interval, as core airflow is critical for these bikes.
- Always use a coolant compatible with magnesium and aluminum alloy components to prevent internal corrosion specific to this model's construction.
Tools & Supplies Needed
- Drain pan
- Socket set (8mm or specified drain bolt size)
- Phillips screwdriver
- Fresh premixed motorcycle coolant
- Cone funnel
- Clean shop rags
- Replacement radiator cap or hoses if needed
Drain the Old Coolant
- Ensure the engine is cold. Never open the system when hot to avoid burns.
- Remove the radiator cap slowly to release any built-up pressure.
- Locate the water pump drain bolt. On the KX500, this is typically on the lower right side of the engine case near the water pump. Place your drain pan beneath and remove the bolt to let old coolant flow out.
- Remove lower radiator hoses if you wish to maximize fluid removal.
- Inspect the coolant. Any brown color or debris signals rust or gasket trouble and further inspection is advised.
Flush the System (Recommended)
- For a thorough job, pour distilled water into the radiator and briefly idle the engine with the drain bolt in place. Shut it down, then remove the plug to let water drain. Repeat as needed until water runs clear.
Refill with Fresh Coolant
- Replace the drain bolt and lower radiator hose, tightening carefully to factory specs.
- With the radiator cap off, slowly pour in fresh premixed coolant using a funnel; fill to just below the filler neck to allow for expansion.
- Top up the overflow bottle (if equipped), filling to the upper mark.
Bleed Air from the System
- With the cap still off, start the engine and let it idle for about 1 minute. This helps purge air pockets.
- Shut off the engine and check the coolant level–top up if necessary. Reinstall the radiator and overflow bottle caps securely.
- Inspect for leaks at the drain bolt, hose connections, and around the radiator cap.
Final Checks & Maintenance Tips
- Recheck the coolant level after the engine cools completely; top off if needed.
- Inspect the radiator fins and the cap’s sealing surface. If the cap does not hold 14–18 psi (as recommended for the KX500), replace it for proper system pressure.
- Consider upgrading to silicone radiator hoses for greater durability if originals show signs of wear.
Notes for 1987 KX500 Owners
- Because older plastics and hoses may degrade, always double-check for any cracks, leaks, or brittle connections before riding.
- The 2-stroke KX500 runs hot under aggressive riding–do not skimp on coolant quality, and never use straight tap water.
- Periodic radiator cleaning is essential; bent fins can often be straightened with a small screwdriver to restore cooling efficiency.
Related Shopping Categories
Shop Radiators for a 1987 Kawasaki KX500 Dirt Bike.
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Shop Tools for a 1987 Kawasaki KX500 Dirt Bike.
Shop Radiator Hoses for a 1987 Kawasaki KX500 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.