Mix only distilled, low mineral water with the antifreeze.
Recommended mixture: 1:1 (distilled water and antifreeze).
Recommended antifreeze: Pro Honda HP coolant or an equivalent high quality ethylene glycol antifreeze containing silicate-free corrosion inhibitors.

Notice. Using coolant with silicate corrosion inhibitors may cause premature wear of water pump seals or blockage of radiator passages. Using tap water may cause engine damage.
Replacement/air bleeding
When filling the system or reserve tank with a coolant (checking the coolant level), place the motorcycle in a vertical position on a flat, level surface.
Remove the fuel tank (page 5-50).
Remove the radiator cap.
Remove the drain bolt on the water pump and drain the system coolant.

The engine must be cool before servicing the cooling system, or severe scalding may result.
Reinstall the drain bolt with a new sealing washer.
Place a suitable container under the siphon hose joint of the reserve tank.
Disconnect the siphon hose from the reserve tank and drain the reserve coolant.
Empty the coolant and rinse the inside of the reserve tank with water.

Reconnect the siphon hose.

Fill the system with the recommended coolant through the filler opening up to the filler neck.

Remove the reserve tank cap and fill the reserve tank to the upper level line.

Bleed air from the system as follows:
1. Shift the transmission into neutral.
Start the engine and let it idle for 2 - 3 minutes.
2. Snap the throttle three or four times to bleed air from the system.
3. Stop the engine and add coolant to the proper level if necessary. Reinstall the radiator cap.
4. Check the level of coolant in the reserve tank and fill to the upper level if it is low.