Kawasaki Ninja Service Manual: Cooling System Flushing

Over a period of time, the cooling system accumulates rust, scale, and lime in the water jacket and radiator. When this accumulation is suspected or observed, flush the cooling system. If this accumulation is not removed, it will clog up the water passage and considerable reduce the efficiency of the cooling system.

• Drain the cooling system (see Coolant Change in the Periodic Maintenance chapter).
• Fill the cooling system with fresh water mixed with a flushing compound.

NOTICE

Do not use a flushing compound which is harmful to the aluminum engine and radiator. Carefully follow the instructions supplied by the manufacturer of the cleaning product.

• Warm up the engine, and run it at normal operating temperature for about 10 minutes.
• Stop the engine, and drain the cooling system.
• Fill the system with fresh water.
• Warm up the engine and drain the system.
• Repeat the previous two steps once more.
• Fill the system with a permanent type coolant and bleed the air from the system (see Coolant Change in the Periodic Maintenance chapter).