How to Change the Coolant in a 1987 Suzuki RM250
Shop parts for a 1987 Suzuki RM250 Dirt Bike.
Keeping your 1987 Suzuki RM250 running cool and performing its best starts with regular coolant changes. This classic two-stroke's cooling system relies on fresh, clean coolant for heat dissipation and long engine life. Use this proprietary MotoSport guide to change your RM250's coolant efficiently and safely, with extra care specific to the model's age and design.
What You'll Need
- New coolant formulated for off-road use (ethylene glycol-based, not pre-mixed with tap water)
- Distilled water
- Catch pan for drained coolant
- 8mm socket or wrench
- Phillips screwdriver (may be needed for plastics)
- New drain plug washer (recommended)
- Protective gloves and safety glasses
How to Change the Coolant
- Allow the bike to cool completely–never work on the cooling system when hot, to avoid serious burns.
- Remove the seat and side plastics if needed for easier access to the radiator and drain bolt.
- Place a catch pan underneath the right side of the engine. Locate the coolant drain bolt at the base of the water pump.
- Remove the radiator cap slowly to release pressure, then fully remove it.
- Use an 8mm socket to loosen and remove the drain bolt. Let coolant empty completely. Expect about 950 ml (1.0 US qt) capacity.
- Inspect and replace the drain bolt washer to ensure a leak-free seal upon reassembly.
- Flush the system: Plug the drain temporarily and fill the radiator with distilled water. Replace the drain bolt and start the bike for a few seconds to circulate (do not let it overheat). Drain again. This removes residue or debris from the system.
- Tighten the drain bolt back in place with a new washer. Do not overtighten–reference the factory spec (approximately 8 lbf–ft).
- Fill the radiator with fresh coolant, up to the bottom of the filler neck. Gently tilt or rock the bike to help release trapped air pockets.
- Reinstall the radiator cap securely.
- Start the engine and let it idle briefly. As the coolant circulates, some air bubbles may work out. Stop the engine, let it cool, and recheck the coolant level. Top off if needed.
Important 1987 Suzuki RM250 Notes
- This model uses a conventional (not pressurized recovery tank) cooling system, so getting air completely out is critical for performance.
- Never use tap water when topping off or flushing, to avoid mineral deposits damaging the cooling system.
- The RM250's aluminum radiators can corrode if mixed with incompatible coolants; always check the coolant is aluminum-safe.
- Inspect your hoses for cracks or leaks–original hoses may be brittle after decades and are a common source of leaks in vintage RM250s.
- If you find stubborn leaks or hear boiling after riding, your cap or radiator could need replacement, a common issue as these bikes age.
Proper Coolant Disposal
Always dispose of old coolant at a certified recycling center–do not pour it on the ground or down the drain, as it's toxic to people and animals.
Why Regular Coolant Maintenance Matters
Maintaining healthy coolant smalls costly engine repairs, prevents overheating on the track, and prolongs the life of your 1987 Suzuki RM250. With just some simple tools and a little time, you’ll keep your classic RM running strong for years to come.
Related Shopping Categories
Shop Radiators for a 1987 Suzuki RM250 Dirt Bike.
Shop Coolant for a 1987 Suzuki RM250 Dirt Bike.
Shop Temperature Sensors for a 1987 Suzuki RM250 Dirt Bike.
Shop Tools for a 1987 Suzuki RM250 Dirt Bike.
Shop Radiator Hoses for a 1987 Suzuki RM250 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.