mhhhhh at first place i was think that radiator was dirty, l take the radiator to the mechanic and wash it, but my R4 still have too hot water in expansion bottle and it make it to dry every time. but it was gasket failure.................
l take my lovely R4 to home, next day l drive it happy..... but l notice there is leak like milk in oil filter............. mechanics told me its mixture of oil and water............. so it needed to do reface cylinder head.....
they open cylinder head for doing reface, while open..one clever mechanics told me that the new gasket is not fit perfectly in sleeves, the cycle of gasket is big compare of sleeves that is why it make mixture of oil and water