_rascal, use the OEM Honda Type-II "blue" coolant that's already pre-mixed. Grab an extra gallon of it, and use that to flush your Wing's radiators.
Drop the old coolant out when the engine is cold, add the Type-II, keep the radiator cap off, and run the bike up to temp. Keep a rag over the fill hole when the engine's running, as the Honda bike thermostats have a bypass section in them that allows quite a bit of coolant to flow even when the thermostat's not open. Add more coolant while the engine is running to maintain a full level, blip the throttle to get things moving and the thermostat to open up, and then shut off the bike and let things drain.
Wait for 20 minutes or so for the engine to cool off, and then fill with the final load of the Type-II. Same drill as before -- cap off, get the engine warm, keep full, shut down, and then do a final top-off before replacing the cap.
Don't forget to clean out your overflow reservoir, and then fill that to an inch or so above the "hot" line. As the bike cools off overnight, coolant will be drawn out, and you should end up just about perfect level-wise when everything's completely cold again.
BTDT many times on my ST1100.