How to Change the Coolant in a 1993 Honda CR125: Step-by-Step Guide
Shop parts for a 1993 Honda CR125 Dirt Bike.
The Honda CR125 is an iconic two-stroke dirt bike known for performance, simplicity, and race-ready handling. Keeping the coolant fresh ensures your 1993 CR125 stays cool under pressure, prevents overheating, and protects internal components. This model uses a straightforward single-radiator system with accessible drain and fill points, but attention to detail matters–especially on older bikes with years of service.
Why Change the Coolant?
- Prevents overheating and engine damage
- Protects aluminum engine/radiator parts from corrosion
- Ensures optimal cooling efficiency
- Removes deposits & old contaminants from the system
What You Will Need
- Fresh motorcycle coolant (avoid automotive coolant with silicates)
- Drain pan
- 8mm socket or wrench
- Soft rag
- Funnel
- Distilled water (for flushing, if needed)
- Replacement crush washer (recommended)
- Gloves & safety glasses
Step-by-Step Coolant Change for Your 1993 CR125
- Ensure the bike is completely cool. Never open the radiator cap when hot—it can cause scalding burns from pressurized coolant.
- Remove the seat and radiators' plastic shrouds for easier access if desired. This step is optional, but makes working around the radiators simpler.
- Locate the radiator cap on the left side of the bike, atop the radiator. Carefully loosen and remove it to release pressure.
- Position your drain pan beneath the water pump cover on the right side of the engine.
- Remove the coolant drain bolt.
- The CR125 drain bolt is an 8mm bolt at the bottom of the water pump cover–look for the copper crush washer. Carefully loosen and remove the bolt so coolant flows out. Allow all coolant to drain fully.
- Inspect the drain bolt and washer. Replace the copper crush washer if it's crushed or damaged. This small step prevents future leaks.
- Flush (optional for best results):
- If the drained coolant is dirty or you're switching coolant types, flush the system by reinstalling the drain bolt, filling the radiator with distilled water, and running the engine gently for a minute or two (do not overheat.). Drain again as in Step 5.
- Reinstall the drain bolt. Tighten snugly–not excessively. The copper washer does the sealing. Overtightening can strip the case threads.
- Fill with fresh coolant.
- Using a funnel, slowly pour the new coolant directly into the radiator fill neck. Fill until it's at the very bottom of the filler neck.
- "Burp" the system.
- Tilt the bike left/right or gently rock it to help release any trapped air. You can also gently squeeze the coolant hoses. Top up again if the level drops. Reinstall the radiator cap.
- Start and warm up the engine.
- Let the bike idle for a few minutes, then shut off and let cool. Recheck the coolant level and top up as needed.
- Reinstall shrouds and seat. Wipe away spills, check for leaks, and you're ready to ride.
CR125 Owner's Tips & Notes
- The 1993 CR125 uses a simple, non-pressurized overflow bottle. Check it for cracks or sludge, and clean or replace if necessary.
- Never use plain water alone for long-term coolant. Always run a quality premix or non-silicate motorcycle formula compatible with aluminum systems.
- Changing coolant every 1-2 years, or after 40-50 hours of ride time, helps avoid build-up in older two-stroke engines.
- Careful with torque when replacing bolts on the magnesium water pump cover–threads can strip easily on vintage CRs.
- Avoid overfilling: leave a small gap at the neck for expansion when hot.
Enjoy Peak Performance
Your 1993 Honda CR125 delivers legendary power—treat it to a fresh coolant change and it will run cool and crisp all season. Stay on top of regular maintenance and always double-check for leaks or signs of overheating after every coolant service.
Related Shopping Categories
Shop Radiators for a 1993 Honda CR125 Dirt Bike.
Shop Coolant for a 1993 Honda CR125 Dirt Bike.
Shop Temperature Sensors for a 1993 Honda CR125 Dirt Bike.
Shop Tools for a 1993 Honda CR125 Dirt Bike.
Shop Radiator Hoses for a 1993 Honda CR125 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.