How to Change the Coolant in a 2007 Suzuki RM125
Shop parts for a 2007 Suzuki RM125 Dirt Bike.
Maintaining the proper coolant level and condition in your 2007 Suzuki RM125 is vital for engine health, especially since this model features a high-revving 2-stroke engine that relies on efficient heat dissipation. MotoSport.com presents this exclusive, step-by-step guide so you can confidently change the coolant on your RM125—plus, we highlight what makes this maintenance task different on your specific bike.
Tools & Supplies Needed
- Metric socket set (8mm socket needed)
- Drain pan
- Funnel
- Distilled water (never use tap water)
- Premixed 50:50 engine coolant (ethylene glycol based, safe for aluminum engines)
- Clean shop rags
- Protective gloves (recommended)
Step-by-Step Coolant Change
- Ensure Engine Is Cool
Never open the radiator cap on a hot engine – wait until completely cool to avoid burns from scalding fluid or steam.
- Stabilize Your RM125
Place your bike securely on a stand or level surface.
- Remove Radiator Cap
Slowly twist off the radiator cap – even a cool engine can have residual pressure. Place the cap somewhere clean.
- Drain Old Coolant
Locate the water pump drain bolt (bottom of the right-side engine case). Place the drain pan underneath.
Use the 8mm socket to carefully remove the drain bolt and allow all coolant to empty into the pan.
Optionally, gently tilt the bike from side to side to remove trapped fluid.
- Flush (Optional for Thoroughness)
Reinstall the drain bolt temporarily, then pour distilled water into the radiator. Remove the bolt again to flush out any old residue. Never use tap water due to mineral content.
Reinstall and tighten the drain bolt securely.
- Refill with New Coolant
Using a funnel, pour the premixed 50:50 coolant slowly into the radiator until it reaches the bottom of the radiator filler neck.
This bike does not have a coolant overflow tank—the coolant level should be checked directly at the radiator.
- Bleed the Cooling System
Gently rock the bike or squeeze upper radiator hoses to burp any trapped air.
Top up as needed.
- Reinstall Radiator Cap
Press down and turn the cap until it locks firmly. Improperly tightening the cap can prevent the system from reaching proper pressure and cause leaks.
- Warm Up & Recheck
Start the bike and let it idle for a few minutes. Shut off, allow to cool, and recheck the coolant level. Add more if necessary.
- Dispose of Old Coolant Properly
Never pour used coolant down a drain or onto the ground. Dispose of it at an approved recycling center.
2007 Suzuki RM125 Model-Specific Notes
- No Overflow Tank: This model does not feature a coolant overflow or recovery tank. Expect minor coolant loss during intensive rides—check the coolant level frequently, ideally before every ride.
- Use the Correct Coolant Mix: Always use a coolant safe for aluminum engines, mixed 50:50 with distilled water to prevent corrosion and overheating.
- Capacity: Fill to the radiator neck; do not overfill.
- Tighten Radiator Cap Firmly: Improperly seated caps can cause loss of coolant and overheating. – always ensure it clicks securely in place.
Regular Maintenance Tips
- Monitor coolant level before every ride, as this model is prone to gradual coolant loss.
- If you notice rapid coolant loss, check for leaks at hoses or the water pump.
- Consider replacing the radiator cap if you notice recurring pressure loss or leaks.
Changing your coolant is a straightforward DIY for any RM125 owner – performing it regularly helps protect your high-strung engine and ensures performance on the trail or track.
Related Shopping Categories
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Shop Radiator Hoses for a 2007 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.