How to Change Coolant on a 2008 Honda CRF150R Big Wheel
Shop parts for a 2008 Honda CRF150R Dirt Bike.Maintaining your 2008 Honda CRF150R Big Wheel is essential for peak performance and engine longevity. Changing the coolant regularly helps your bike run cool, improves reliability, and prevents internal corrosion. This guide details the steps specific to the CRF150RB, including key model notes you should know before you begin.
What Makes the 2008 Honda CRF150R Big Wheel Special?
- The CRF150RB features a high-performance, liquid-cooled four-stroke engine – its compact dual-radiator system is designed for aggressive riding and racing conditions.
- The Big Wheel (RB) variant uses larger wheels, giving extra ground clearance but requiring the same cooling system service steps as the standard CRF150R.
- The cooling system capacity for a complete change is approximately 0.76 liters (0.80 US qt).
What You Need
- Fresh, high-quality motorcycle coolant (Pro Honda HP Coolant recommended)
- Distilled water (if flushing the system)
- 8mm socket or wrench (for drain bolt)
- Drain pan
- Funnel
- Clean rags
- Protective gloves & eyewear
Step-by-Step: Coolant Change Procedure
- Let the engine cool completely before beginning. Hot coolant can cause burns.
- Remove radiator cap (located on the left side of the bike at the top of the left radiator). Open slowly to release any pressure.
- Locate the coolant drain bolt. It is the lowest bolt on the water pump cover (right side of the engine). Place your drain pan underneath.
- Remove the drain bolt and existing sealing washer, allowing old coolant to fully drain out. Dispose of old coolant safely, as it is hazardous to animals and the environment.
- If flushing: Reinstall the drain bolt finger-tight, fill the system with distilled water, then run the engine for 1–2 minutes at idle with the radiator cap off. Turn off, let cool, and repeat the drain step until the water runs clear. Do not use tap water (minerals can cause corrosion).
- Reinstall the drain bolt with the sealing washer. Tighten to manufacturer specs (usually hand tight plus a quarter turn).
- Refill with new coolant through the radiator opening. Fill slowly until the coolant is visible just below the cap seat.
- Burp the system: Tilt the bike side-to-side and gently squeeze the radiator hoses to release trapped air. Briefly crank the engine (with the spark plug disconnected for safety) to circulate coolant and push remaining air out.
- Top off coolant as needed so it stays at the proper level.
- Reinstall radiator cap securely.
- Start the engine, let it idle for a few minutes, then check for leaks and recheck the level. Top up if necessary.
CRF150R Big Wheel Model Notes
- The cooling system is pressurized and sensitive to trapped air – always burp the system thoroughly before riding.
- Be alert for white residue or coolant smell near the water pump, which can indicate a water pump seal issue. The 150R uses a high-revving design that can stress seals if coolant level is not maintained.
- Do not overfill. Overfilling can cause coolant to overflow through the radiator cap when hot.
- Check your coolant after the first few rides, as the level may drop slightly once all air is purged.
- Never ride with low coolant or use coolant containing silicates, which can damage your water pump.
When to Replace
- Change coolant every two years or each racing season, whichever comes first, or after any overheated engine incident.
Final Tips
- Store extra coolant in a clearly labeled container, out of reach of pets and children.
- Use only coolant approved for aluminum engines.
Keeping your CRF150RB's cooling system fresh will help protect your engine, boost performance, and keep you on the track longer. Make coolant changes a routine part of your maintenance strategy.
Related Shopping Categories
Shop Radiators for a 2008 Honda CRF150R Dirt Bike.
Shop Coolant for a 2008 Honda CRF150R Dirt Bike.
Shop Temperature Sensors for a 2008 Honda CRF150R Dirt Bike.
Shop Tools for a 2008 Honda CRF150R Dirt Bike.
Shop Radiator Hoses for a 2008 Honda CRF150R 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.