How to Change the Coolant in a 1987 Kawasaki KX80 Big Wheel
Shop parts for a 1987 Kawasaki KX80 Big Wheel Dirt Bike.
Maintaining your 1987 Kawasaki KX80 Big Wheel is essential for reliable performance on and off the track. One critical yet often overlooked aspect of maintenance is the cooling system. The KX80BW's liquid-cooled engine depends on clean, effective coolant for longevity and optimal temperature regulation. Below, you'll find a proprietary MotoSport step-by-step guide to changing the coolant, tailored specifically for owners of this legendary model.
Before You Begin: What Makes the 1987 KX80BW Unique
- Big Wheel Difference: This variation features larger wheels and tires than the standard KX80, improving stability, especially for younger riders still growing into full-size machines.
- Liquid Cooling System: The 1987 KX80BW uses a compact, efficient radiator and water pump setup. Always make sure to use the correct coolant type compatible with magnesium and aluminum alloy engine components to avoid internal corrosion.
- Vintage Construction: Older seals and gaskets are more susceptible to decay and may require closer inspection or replacement during routine coolant changes.
Required Supplies & Tools
- Fresh coolant formulated for dirt bikes (ethylene glycol-based, without silicates)
- Drain pan
- Screwdrivers or nut drivers (for shroud & drain bolt removal)
- Protective gloves and rags
- Distilled water (for flushing)
Step-by-Step Guide to Changing Coolant
-
Ensure Safety
Make sure the engine is completely cool before starting. Hot coolant can cause burns. -
Remove the Radiator Cap
Gently release the radiator cap on the left side of the bike. If you feel pressure or hissing, let it dissipate before removing fully. -
Access the Drain Bolt
Place your drain pan under the water pump, located at the bottom of the right engine case.
Remove the water pump drain bolt (usually a small 8mm bolt on the water pump cover). Let all old coolant drain out. -
Flush the System
Reinstall the drain bolt, then fill the radiator with distilled water. Run the engine for 1-2 minutes (with cap on loosely), shut off, and drain again to remove contaminants and residue. -
Inspect Seals & Hoses
Check rubber hoses, clamps, radiator cap, and visible seals for cracks, bulges, or leaks. Replace any worn pieces to prevent future issues. -
Fill with Fresh Coolant
Tighten the drain bolt snugly. Pour new coolant into the radiator until just below the filler neck. -
Bleed Air from the System
Slowly tilt the bike from side to side to release trapped air bubbles.
Start the engine and let it idle with the radiator cap off for a few minutes, topping up as necessary. Watch for bubbles signifying air release. -
Reinstall the Radiator Cap
Once bubbling stops and the coolant stays at a constant level, secure the cap. Wipe away any spills. -
Final Checks
After riding and allowing the bike to fully cool, double-check coolant level. Top off as needed. Inspect for leaks at all joints.
Additional Model-Specific Tips
- Use only coolants designed for modern motocross bikes to avoid internal corrosion and premature gasket failure.
- Monitor for any mixing of engine oil and coolant, which could indicate a failed seal or gasket—especially on vintage KX models.
- If your KX80BW is still running original radiator hoses, consider proactively replacing them for improved reliability.
Consistent coolant changes extend the life of your 1987 Kawasaki KX80 Big Wheel, keep the engine running at peak power, and help prevent catastrophic overheating. Always follow manufacturer torque specs when reinstalling drain bolts, and remember: proper maintenance is your ticket to more rides and fewer repairs.
Related Shopping Categories
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Shop Tools for a 1987 Kawasaki KX80 Big Wheel Dirt Bike.
Shop Radiator Hoses for a 1987 Kawasaki KX80 Big Wheel 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.