ZX-6R.us

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 section below).
  • Fill the cooling system with fresh water mixed with a flushing compound.
CAUTION
Do not use a flushing compound which is harmful to the aluminum engine and radiator. Carefully follow the instructions supplied by themanufacturer of the cleaning product.
  • Warm up the engine, and run it at normal operating temperature for about ten 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 section below).

Coolant Change

⚠ WARNING
To avoid burns, do not remove the radiator cap or try to change the coolant when the engine is still hot. Wait until it cools down. Coolant on tires will make them slippery and can cause an accident and injury. Immediately wipe up or wash away any coolant that spills on the frame, engine, or other painted parts.
Since coolant is harmful to the human body, do not use for drinking.
  • Remove:
        Upper Fairing Assembly (see Upper Fairing Assembly
        Removal in the Frame chapter)
        Radiator Cap [A]
    • Remove the radiator cap in two steps. First turn the cap counterclockwise to the first stop. Then push and turn it further in the same direction and remove the cap.
 Remove Radiator Cap
  • Place a container under the drain bolt [A] of the water pump cover.
  • Drain the coolant from the radiator by removing the drain bolt.
 Remove Drain Bolt
  • Remove:
        Coolant Reserve Tank Mounting Bolts [A]
        Cap [B]
  • Pour the coolant into a container.
  • Tighten:
    Torque - Coolant Reserve Tank Mounting Bolts: 6.9 N·m (0.70 kgf·m, 61 in·lb)
  • Tighten the drain bolt with gasket.
    Torque - Coolant Drain Bolt (Water Pump): 8.8 N·m (0.90 kgf·m, 78 in·lb)
 Remove Reserve Tank
  • Fill the radiator up to the radiator filler neck [A] with coolant, and install the radiator cap.
    • NOTE: Pour in the coolant slowly so that it can expel the air from the engine and radiator.
  • Fill the reserve tank up to the “F” level line with coolant, and install the cap (see Coolant Level Inspection).
 Fill Radiator
CAUTION
Soft or distilled water must be used with the antifreeze (see below for antifreeze) in the cooling system.
If hard water is used in the system, it causes scales accumulation in the water passages, and considerably reduces the efficiency of the cooling system.
    Water and Coolant Mixture Ratio (Recommended)
        Soft Water: 50%
        Coolant: 50%
        Freezing Point: –35°C (–31°F)
        Total Amount: 2.5 L (2.6 US qt)
  • NOTE: Choose a suitable mixture ratio by referring to the coolant manufacturer’s directions.
  • Bleed the air from the cooling system as follows.
    • Start the engine with the radiator cap removed and run it until no more air bubbles [A] can be seen in the coolant.
    • Tap the radiator hoses to force any air bubbles caught inside.
    • Stop the engine and add coolant up to the radiator filler neck.
  • Install the radiator cap.
  • Start the engine, warm it up thoroughly until the radiator fan turns on and then stop the engine.
  • Check the coolant level in the reserve tank after the engine cools down.
    ★ If the coolant level is lower than the “L” level line, add
    coolant to the “F” level line (see Coolant Level Inspection). 		Bleed Cooling System
CAUTION
Do not add more coolant above the “F” level line.