Yes, thanks for that info, Pleiades.

I've stayed with the pre-mixed Yamaha coolant with both my water-cooled bikes. I realise that owners who aren't the original buyers won't necessarily know what coolant is currently used.

I do know that even the Yamalube coolant is corrosive when exposed to air long-term. I was away from my WR250R for three months. Coolant drooled from a compressed thermostat seal, dribbled into the valley behind the cylinder, and spread all around the cylinder base. It turned into an aqua-blue gelatinous substance, and has left marks on the starter-motor and aluminium components.

I change my coolant yearly on this bike, as it's used in very hot weather continuously (and occasionally and briefly in sub-zero temps - I don't know how you people do it!!).