I too have expierienced a loss of coolant. I have already replaced my clamps(crap, for sure!) I guess I don't know where it's going. I keep my bike in a heated garage and have noticed no leaking coolant.
Bad head gasket? I don't know and it didn't seem like enough to worry about, but it was about half of the overflow tank that came up missing. I really haven't checked as often as I should. I have already had a pinhole in the rad from a rock shot, but successfully repaired that. It could be a leak that only appears when hot.
Keep us posted,
09 Xcountry-the money pit
75 CB400F Supersport-close to stock and for sale
79 CB400T2- so I don't cut up the 400F
Why do I want a CBR250R so bad?