My dad and I always put the engine in a crock pot full of antifreeze. We let the engine cook for about 8 hours to 24 hours. When you put the engine in the crock pot, it will also get all of the oil and gum out of your engine. After we cook the engine, we wash all the parks up with a tooth brush and a rag. After that, we put the engine back together and oil it with after run oil. All of our engines get pretty clean for the following year. Hope i could help.

Airplane_boy