A mechanic was removing a motor from a Harley when a world famous surgeon walked into the shop. The mechanic yelled across the floor to the doctor, "Hey Doc, can I ask you something?"
The surgeon was a bit surprised but he walked over to the mechanic. The mechanic straightened himself up and wiped his hands with a rag and said, "Look at this engine doc, I can also open hearts, take out valves, fix 'em, put 'em back in and when I'm done they'll work just like new. So how come you get the big bucks when I barely have enough to get by?"
The doctor leaned in close to the young mechanic and whispered, "Try doing it with the engine running."