I am often asked the above questions and it usually means a long answer, as a service to regular browsers this is my method. Free off by using heat, I use a small gas torch and wearing gloves, heat the cylinder and main bearing area as hot as you can bear, or until oil smokes and with a prop on turn gently by hand until it frees. Then apply penetrating oil such as Plus Gas, to aid lubrication, finally apply some thin oil. Never remove screwed in cylinders from stuck engines without first freeing off, otherwise you will screw the con-rod into oblivion. To clean I now use Fairy Power Spray, an oven cleaner which brings up castings like new and is fairly benign. For those of you having dificulty finding this material it is contained in a green plastic trigger operated 375ml bottle and has an image of an infant wearing boxing gloves on one side!! Read the instructions as some surfaces can be damaged. Gun Cleaning fluids and cellulose thinners can also be used to remove thin oil deposits and glow residues, but needs precautions so wear rubber gloves and do not inhale the vapour. Thats about it! Remember a clean engine is more attractive and gets a better price!!

John Goodall.