Hi, everyone!!

I just purchaced an engine that has a few flights on it. then it was put away for about 5 years. the internals are good and loose. (it runs fine) Here is my question. How do you get the brown baked on gunk off of the out side of the engine. I know it does not affect the perfomance of the engine but I just like things to look nice. If at all possible I do not want to take the motor apart. Thanks for the help every one always comes through.