How to Change the Coolant in a 2006 Suzuki RM125
Shop parts for a 2006 Suzuki RM125 Dirt Bike.
Keeping your 2006 Suzuki RM125 running cool on the track or trail hinges on proper coolant maintenance. This step-by-step guide gives you everything you need to flush and replenish your cooling system, plus special notes for RM125 owners.
Why Change Your Coolant?
Coolant is vital for protecting your RM125's engine from overheating and possible damage, especially during aggressive riding or summer heat. Old or contaminated coolant becomes less effective and can cause corrosion in the cooling system – compromising performance and reliability.
Supplies Needed
- Compatible engine coolant (silicate-free, formulated for aluminum radiators)
- Bucket or pan for waste coolant
- Socket set (8mm and 10mm)
- New drain bolt gasket washer
- Clean rags
Step-by-Step Coolant Change Process
-
Let the Bike Cool Completely.
Never remove the radiator cap when hot – steam or hot coolant can cause severe burns. -
Remove the Shrouds.
Use an 8mm socket to take off the three bolts on each radiator shroud for clear access to the radiator cap and overflow bottle, if equipped. -
Open the Radiator Cap.
Slowly unscrew the cap to release system pressure. -
Locate and Remove the Coolant Drain Bolt.
The drain bolt is found at the bottom of the water pump cover (right side of engine). Place a drain pan directly underneath.
With a 10mm socket, remove the drain bolt and allow coolant to fully drain. -
Inspect and Replace Gasket Washer.
Always install a new gasket washer to ensure a perfect seal and prevent leaks. -
Reinstall the Drain Bolt.
Torque the drain bolt to 11 N·m (8 lbf–ft). -
Flush if Needed.
If switching coolant types (e.g., water-based to silicate-free antifreeze), flush the system with compressed air. Remove radiator hoses and blow air through to remove old fluid entirely. Never use plain water for flushing aluminum radiator systems. -
Fill with New Coolant.
Pour coolant into the radiator neck until it reaches the bottom of the filler hole. The correct capacity for the RM125 cooling system is about 950 ml. -
Remove Air Pockets.
Start the engine briefly (without cap) to help air escape. Some models have a dedicated bleeder screw – loosen it to aid burping the system, then retighten. -
Install Radiator Cap and Shrouds.
Reinstall cap securely and bolt shrouds back into place. -
Dispose of Used Coolant Safely.
Never pour old coolant down drains – take it to an authorized recycling location.
RM125 Model-Specific Notes
- The RM125 uses an aluminum radiator and water pump, requiring silicate-free and phosphate-free coolant formulated for dirt bikes – this prevents internal corrosion and scale formation.
- After any coolant change, inspect for leaks at the radiator seams, hoses, and drain bolt – aging gaskets and hoses are common issues on older RM125 models.
- Regular coolant changes and careful attention to fluid levels help preserve engine power and extend the life of your RM125 under hard riding conditions.
Additional Tips
- If your RM125 overheats or shows visible coolant leaks, check the radiator core and hoses for bends, punctures, or deterioration – quick repair or replacement restores cooling efficiency.
- Always use gloves. Coolant is toxic and can irritate skin and eyes. Wash hands and cleanup tools after any spill.
Related Shopping Categories
Shop Radiators for a 2006 Suzuki RM125 Dirt Bike.
Shop Coolant for a 2006 Suzuki RM125 Dirt Bike.
Shop Temperature Sensors for a 2006 Suzuki RM125 Dirt Bike.
Shop Tools for a 2006 Suzuki RM125 Dirt Bike.
Shop Radiator Hoses for a 2006 Suzuki RM125 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.