With the engine off and cool, open the radiator drain petcock and drain the coolant into a container for proper disposal. Close the petcock, pour in Royal Flush (for small systems like motorcycles the entire contents may not be appropriate), then fill with water. Replace the radiator cap, start the engine and turn the heater on high. Run the engine for at least 10-15 minutes or take a short drive. Please be aware that Royal Flush is completely safe for the cooling system and is non-corrosive. Therefore Royal Flush can be left in the cooling system for an entire day or more. If you choose to leave Royal Flush in the vehicle for an extended period, try to do this during a period of above freezing ambient temperatures. Neither Royal Flush nor Purple Ice provide any anti-freeze protection or boil over protection, so avoid overheating the engine.

After the flushing with Royal Flush is complete, turn off the engine, allow it to cool, open the drain petcock and drain into a disposal container. Then flush the system thoroughly with water. Close the petcock and refill the cooling system with straight water. Replace the radiator cap and run the engine again for at least 10-15 minutes. Turn off the engine, allow it to cool and drain and flush again with water as before. After the water flushing is complete, drain the water, close the petcock and refill with an appropriate water/antifreeze mixture for proper freeze protection in your region and replace radiator cap.

For best results and to improve heat transfer and corrosion protection also install - Purple Ice Radiator Coolant Additive