There are some jobs I can't do on the motor car because it needs to go up on the hoist, which I don't have. Also I don't have CV joint breakers. I'll do the jobs I can, but I'll leave the jobs I can't to people who have the proper equipment.
When the bill comes in, there it is, 15 minutes. General fettling. The girl on the desk says I can't charge you for this, what is 'fettling'?
How do you define 'fettling'? A squirt here and there with the grease gun? Tightening things up a bit? A drop of oil in the carb damper?
It's something a motor mechanic who takes pride in his work does and oops, there went 15 minutes. He has to book his time to something.