My son trying to do the right thing has had a go at repalcing the top end on his Husky 125 while I`m away on holiday, on my return (two weeks later) he asks for a hand to re-assemble it and to my horror find that he did not drain the coolant out before removing the cylinder, you guessed it, crank is half full of coolant
Now the thing is that I cannot see any signs of rust and now think has the rust inhibitor in the coolant saved me needing to do a complete rebuild