For the very hard to remove lacquer on the engines, strip the engine of plastic. Take it apart. Place in a $5 individual crockpot, cover with any antifreeze. Cook it for about 5 hours, remove, wash, it should be like new. If not, then brush, or do what ever needs to be done. You will be amazed. With the Dawn, this works with those engines that do not have really "cooked" on fuel. Use them both with a little elbow grease and take a pic! Old to new!