Don't be rude at work (even if you think it would be funny)

Sometimes I really want to be a smart aleck. That's okay too, among family and friends in playful situations. But generally when working, you have to choke down that urge.
I called a customer yesterday morning to tell him that his machine had me stumped (yes, some things are beyond even old Marty). I told him I tried everything I knew to try but to no avail. I suggested he pick it up and take it to an electrician, as the motor simply would not run. I even suggested a place for him to take it to, someone I've known for years who is honest and does good work in a timely manner.
He came into the Shop within the hour. As he wheeled his unit towards the door he asked, "So what do you think I should I do?".
This is where not being a smart aleck is important. I said, as though I had said nothing sixty minutes ago, to take it to the electric motor shop.
Yet that is not what I wanted to say.
I wanted to say, perhaps, I have no idea what to do, simply to see if he'd remind me I had recommended someone. Because he would, you know, even though he just seemed himself ignorant of what I had said on the phone.
Or, it occurred to me, I might have led him through an entirely new process. I might have explained the situation in snide detail.
I might have started with: Okay, here's the deal. Try to keep up.
I sell and repair drain snakes. It's what I do to make a living.
Are you with me so far? Good.
I wanted to call and tell you that I could fix your machine for this very reasonable price in this perfect time frame, because I sell and repair snakes. I wanted to be able to repair your snake, not send you away.
Still with me?
Now, all that being said, don't you think that if I had had any solid idea what to do I would have done it? Why might I have you pick it up to take somewhere else otherwise?
Got that?
Good. Because I was afraid I might have to repeat it.