A small boy was pushing a gasoline-powered lawnmower down the street
with a "For Sale" sign on it.  A man stopped him asked if the mower
would run.  The boy told him it would so the man bought it.  A while
later, the boy was walking past the man's house and saw him pulling
repeatedly on the starting rope with no success.  The man noticed the
boy and said, "I thought you told me this mower would run!" The boy
said, "Well you have to use some cuss words to make it start." The
Man said, "Son, I'm a preacher; I don't know any cuss words!" The
boy replied, "You keep pulling on that starter rope and some'll come
to you!"