The mechanic and the surgeon

A mechanic was removing a cylinder head from the motor of a motorcycle when he spotted a well-known cardiologist in his shop. The surgeon was there waiting for the service manager to take a look at his bike when the mechanic shouted from across the garage, "Hey Doc, can I ask you a question?"

The surgeon, a bit surprised, walked over to where the mechanic was working on the motorcycle.

The mechanic straightened-up, wiped his hands on a rag and asked, "So Doc, look at this engine. I open its heart, take the valves out, repair any damage, and then put them back, and when I'm finished, it works just like new. So how come I get such a small salary and you get the really big bucks especially when you and I are doing basically the same type of work?"

The surgeon paused, smiled, leaned over, and whispered to the mechanic...."Try doing it with the engine running!"