A mechanic was removing a cylinder head from the motor of a Harley-Davidson when he spotted a well-known heart surgeon in his shop. The surgeon was there waiting for the service manager to come take a look at his bike.

The mechanic shouted across the garage, "Hey, Doc, can I ask you question?"

The surgeon, a bit surprised, walked over to the mechanic 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 valves out, fix 'em, put 'em back in, and when I finish, it works just like new."

"Yes, so what's your question?" the doc asks.

"Well, how come I get such a small salary and you get the really big bucks, when you and I are doing basically the same work?"

The surgeon paused, smiled, leaned over, and whispered to the mechanic, "Can you do it with the engine running?"